Hi All,
this morning this arrived in the post :) The plan is to mod it to it's limits. To start with it will be brought up to 6128+ level with the additional 64K and the floppy controller / separator. After that I have obtained a slimline 3.5in Laptop floppy which I will try to squeeze inside the case somewhere (without removing the tapedeck).
Then I will try to install a MegaFlash, additional 512K RAM, S-Video output, a USB Port for AMX Mouse, a reset switch, an ABBA switch all internally and depending on the space that's left (if any), I may look at adding a few other bits and pieces later.
I'll be documenting the lot and posting it all here. Stay tuned...
Bryce.
All information regarding the 464+ to 6128+ conversion can now be found on this wiki page: http://www.cpcwiki.eu/index.php/464Plus_Conversion (http://www.cpcwiki.eu/index.php/464Plus_Conversion)
A shame such things don't magically arrive with *my* post.
Stickying this, should be very interesting.
Could you make an auto eject for the tape player top so you can use it to launch things at people?
A friend of mine had such a stereo deck; tape was inserted vertical to the deck (which means, horizontal, like a car's tape player). This+a very strong spring+feather touch buttons=fatalities.
it's in perfect mint condition... truly sad those had so many missing components... and tapes.
128K and CD-Rom could have been perfect (also add the FDC inside...) :P
there was one recently for sale on ebay from Ireland, only one bid went on it (I was tempted) nice peice of kit you've got there
I 'consoled' myself by getting a couple of GX4000's, may decide to mod one of them one day
Quote from: BiNMaN on 17:22, 08 June 12there was one recently for sale on ebay from Ireland, only one bid went on it (I was tempted) nice peice of kit you've got there
The one from Ireland is the one Bryce is working on. ;-)
I was the only bidder. Some day in the future when Bryce is done with this, it'll be my new main CPC. :)
You lucky b@st@rd.
OOoo! Sounds like a great project, strangely enough your plans aren't a million miles away from my next GX4000/Plus Project! I even have the slimline FDD sitting waiting in the spare room, I also have a couple of dead laptops with slimline drives so if you need one I might have one for you but I'm unsure about model/make as I haven't removed them yet.
I also had a delivery today from the bay of E. A (sold as) faulty 464 first generation I was going to gut to use for my next project for the princely sum of £10.50 including delivery. I was quite amazed though how great the condition of this machine is, if you ignore the crack on the cassette drive and the sticker on the left of the case. It's near mint and I can replace the cassette door as I have a spare. The keys are like new, bright with no yellowing! Could all just do with a bit of a clean. It also works perfectly! And it appears to have a very low serial on it--- 2502. Here is a photo, which to be honest doesn't do it justice at all...
[attach=2]
I have to ask as I am also planning a 512k memory expansion, are you designing your own upgrade or are you using a extant schematic? I was intending to use the Inicron 512k Upgrade (as listed in the wiki) in my mod but if you have a better idea I would be interested to hear about/steal it ;) I am also planning a built in MegaFlash and an HxC docking port for an external cased HxC but I'm not sure about how I intend to deal with the cassette unit as I'm quite keen on having a sawn off 464 case but I'm undecided right now. I'm going to have a crack at building the MegaFlash unit myself (just to say I did) if it all goes horribly wrong I may have to buy another from you!
I will be watching this thread very closely! Good luck! ;D
If you do saw the end off your '464, add a new side panel to the cassette part and try to keep the cassette drive as an operational unit so you could load cassettes if you wanted to.
Personally, I prefer the look of the '464 as it is.
I have made my own design 512K RAM expansion. I haven't built one yet, but it should be a bit smaller than the MegaFlash and easily fit inside the 464+. As soon as I have tested it, I'll be releasing the plans for that too.
I have a 3.5in slimline drive (also salvaged from a dead laptop), which I will start converting this weekend hopefully.
Bryce.
Then we just need to figure out where to put it. :-)
The disk drive I mean.
The only sensible place at the moment seems to be in the middle between the cartridge slot and the tapedeck with the slot for the floppy at the rear. There's not enough space under the tapedeck or the keyboard, so there's nowhere else (internally) available.
Bryce.
Quote from: Bryce on 12:54, 09 June 12
The only sensible place at the moment seems to be in the middle between the cartridge slot and the tapedeck with the slot for the floppy at the rear. There's not enough space under the tapedeck or the keyboard, so there's nowhere else (internally) available.
I'm wondering if another option is to mount the drive on top of the machine with the slot facing sideways the same direction as the cartridge slot. It probably won't look great, but would probably be more handy?
If it was externally almost the same could be achieved of course, except you'd have the wired too.
You mean just "glued" on top??
Bryce.
This looks very interesting! I myself have thought about how you could manage to fit a full set of upgrades inside a CPC, but only in regard to the modding of the case, as the electronics' bit is not my league.
So, one vague idea would be to raise the back side of the Plus' case. This would result in widening the angle of the keyboard a little bit and would also mean that the upper part of the casing (where the logo and tape deck are) would not be parallel to the desk but have an angle as well.
The goal would be to essentially make room in the bottom, and place everything under the motherboard itself. Of course this would mean that you need to modify the mounting holes for the screws for the existing hardware AND the holes to screw the case back in. And on top of that, this would be the more challenging part I think, you need a custom designed extra piece of plastic for the casing that will fit between the upper and the lower parts of the original Plus case.
This custom case part will raise the back side for as much as you want and should have some mounting mechanisms of its own for holding the new hardware AND support the existing hardware. And at the same time not-look-awful :P
Needless to say that for modding an old gen 6128 you have to make a new box if you want to fit new hardware in it :P
rb
I'm dribbling just thinking about the whole idea, sounds great man! .If someone can pull such a project, that's you Bryce
Quote from: Bryce on 14:25, 09 June 12You mean just "glued" on top??
Yes. As I said, not pretty, but more practical than the rear solution.
Not saying that's what I'd like though. Just trying to think up more options.
At the moment, I'm still waiting for parts to arrive, but that's no reason to sit around staring at the wall, so today I converted the Slimline Floppy drive. It's a Mitsumi D353G which was used in many Laptops over the years. Other than it being tiny: 12.5mm high and not much bigger than the disk itself, it also has some other advantages.
[attach=2]
Laptop floppies use the 26way Shugart standard, which gives separate /DSKCHG (not needed for the CPC) and a READY signal (required for the CPC). They also only need 5V. The only dis-advantage is that they are usually connected with an FPC cable, so an adapter is needed. Unfortunately, the PCB is embedded inside the frame, so you need to disassemble quite a bit.
[attach=3]
Once it's apart I removed the FPC connector and soldered some wires to connect to the adapter.
[attach=4][attach=5]
This is the adapter:
[attach=6]
Soldered it all up and put it back together.
[attach=7]
Then I connected it up to my 6128+ for a quick test. All was fine, ready to be installed into the 464+ when the rest of the parts arrive. When I get a chance, I'll put this all in the Wiki, including the pinouts for the Floppy to Adapter.
Bryce.
Quote from: Badstarr on 22:47, 08 June 12
I'm not sure about how I intend to deal with the cassette unit as I'm quite keen on having a sawn off 464 case but I'm undecided right now.
Heh, I'm considering doing the very same thing to use with my FPGA project. :)
I even have a 464 with a completely destroyed motherboard thanks to an over-enthusiastic modder as its previous owner... (best part of the story is he claimed it was working before he put it into storage, so obviously it's the storage elves that can't be trusted!)
You can use almost any cassette player on a CPC, it doesn't have to be a CPC one.
Bryce.
What about adding a counter on the tape driver ?
also I've heard the 464PLUS' tape driver is not connected to the sound output so you can't hear the bit flow, nor audio tapes while playing...
Quote from: ralferoo on 07:47, 13 June 12
Heh, I'm considering doing the very same thing to use with my FPGA project. :)
I even have a 464 with a completely destroyed motherboard thanks to an over-enthusiastic modder as its previous owner... (best part of the story is he claimed it was working before he put it into storage, so obviously it's the storage elves that can't be trusted!)
Ah yes those little "storage elves" sometimes I hear them at night singing as they dance their way through the attic. Fortunately they rarely damage any of my things. As for over enthusiastic modding, I have seen some weird goings on in some of the faulty items I have bought from ebay. +5v Shorted to the cassette chassis due to bare twisted wire connections, a power supply connection soldered (badly) to a VCC pin on a Logic IC which it would appear made friends with a nearby pin it seems blixing out nearly every component in a 6" radius. Sometimes my own "quick fixes" can be a little "ghetto" but when I have seen what other people have done it really makes me wonder if screw drivers and CPCs should be issued only to people who can prove they can be trusted ! :laugh:
Quote from: MacDeath on 20:15, 13 June 12
What about adding a counter on the tape driver?
I suspect that will be very difficult. Not a bad idea, but most likely way too troublesome.
Quote from: MacDeath on 20:15, 13 June 12also I've heard the 464PLUS' tape driver is not connected to the sound output so you can't hear the bit flow, nor audio tapes while playing...
Not a bad idea either, and probably one that can actually be done. What do you think Bryce? One of them small flat speakers attached somehow?
Correct (MacDeath) the sound output (Pin 7) on the cassette player isn't connected. But the Op-Amp for this also isn't present. I could easily add this, but I suspect you (MrLou) will opt not to want this, because the intended use is mainly for music and you have already mentioned your dis-like of the humming on the sound output of the 464. This is probably why Amstrad chose to remove it. Having a non shielded wire routed from the tape deck on the right all the way over to the AY on the left is probably a major source of humming on the output. And do you really need to hear the tape loading? Is it worth having a humming in the speaker? I could connect it to its own speaker, not connected to the normal sound output at all? That would avoid the humming, but I will need to find a space in the CPC.
As far as the counter is concerned, I have a few counters here, I'll take a look at how much work it would be to add this.
Bryce.
Quote from: Bryce on 09:16, 14 June 12
Correct (MacDeath) the sound output (Pin 6) on the cassette player isn't connected. But the Op-Amp for this also isn't present. I could easily add this, but I suspect you (MrLou) will opt not to want this, because the intended use is mainly for music and you have already mentioned your dis-like of the humming on the sound output of the 464. This is probably why Amstrad chose to remove it. Having a non shielded wire routed from the tape deck on the right all the way over to the AY on the left is probably a major source of humming on the output. And do you really need to hear the tape loading? Is it worth having a humming in the speaker? I could connect it to its own speaker, not connected to the normal sound output at all? That would avoid the humming, but I will need to find a space in the CPC.
Less humming / noise is definitely better than being able to hear the tape loading. It's important to be able to record CPC tunes without noise.
It would however be nice to be able to hear the loading. I was thinking it could have its own speaker, one of those very small flat speakers from Game & Watch games? No need to be able to control volume of it. It just needs to be low volume so it can be heard, with the option of turning it off again (from inside the machine - no more switches outside). ;)
I'll take a look at where I could connect a small piezo speaker then.
Bryce.
Cool. :-)
I'm thinking it will be very helpful when needing to find the location of a certain program on the tape. Especially when/if there is no counter.
Maybe instead of an on/off switch inside, it could be a variabel resistor? I mean adjust volume if needed, or completely turn it off by turning it all the way down? But still only possible from inside the machine. No more switches outside. :-)
The Classic 464 actually uses a very indirect way of making those sounds. The Tapedeck isn't actually connected directly to the speaker anywhere. The data leaving the tape PCB is already in a digital form and is passed through the AY and back to the speaker as far as I know. So the Firmware / CPU must play some part in linking the two.
Bryce.
I think this was discussed in the past... so actually the tape unit already demodulates it, then the main unit modulates it again to allow it through the speaker? But if that's so, how can you hear it when a tape is bad and wobbles and flutters? I don't think the CPC would recreate that effect from a digital signal?
Quote from: Bryce on 11:53, 14 June 12
The Classic 464 actually uses a very indirect way of making those sounds. The Tapedeck isn't actually connected directly to the speaker anywhere. The data leaving the tape PCB is already in a digital form and is passed through the AY and back to the speaker as far as I know. So the Firmware / CPU must play some part in linking the two.
Bryce.
i don't think it's passed through the ay because it doesn't have an input and no writing is done to ay for that during loading/saving.
as far as the cpu is concerned it reads bits from the 8255, and writes bits to it for saving.
how the sound actually gets to the speaker I don't know.
maybe the circuit has some leakage?
Slightly off-topic at this stage, but here's an explanation of the cassette loading circuitry:
The tape unit doesn't fully demodulate the signal, it just digitises it, ie: there are only two levels 0V and 5V. This is fed directly back to the PIO and "internally" forwarded on to the AY. If you take a look at the 464 Schematics below, you can see the connections (or lack of them). The Op-Amps I've labelled (A to D) do the following:
Tape loading related:
Op-Amp A: Amplifies the analogue signal from the tape head to a usable voltage (but still analogue).
Op-Amp B: Is configured as a comparitor and Digitises the signal by jumping between 0V and 5V depending on the analogue voltage received. From this point on the signal is digital, but not demodulated, ie: the 1s and 0s are not all the same length.
AY output related:
Op-Amp C: Is a pre-amp for the output of the AY which then goes to the volume control (it is only connected to the output of the AY and nothing else, which means that ALL sounds from the speaker have been produced by the AY)
Op-Amp D: Is the end stage which drives the speaker.
If the analogue signal from the tape were to go directly to the speaker, then there would have to be a connection from the output of Op-Amp A (Pin 7 of the LA6324) to the input of the pre-amp (Pin 12 of the LA6324) or Pin G of the cable connection, but it's not there. Sound In and the pre-amp are only connected to the AY, which means the sound came from there. In the second schematic you can see that the Digital output (Pin E) also only goes to B7 of the of the PIO, so it is definitely a digital signal and is not connected to anything else.
Bryce.
@Arnoldemu: It's a bit too clear and controllable to be leakage. You can completely turn it down with the volume control, which would mean that it leaks (loudly and clearly) to the pre-amp, but not at all to the end-stage? This seems unlikely.
Bryce.
How can the PIO forward it to the AY? The only connects it has are 2 lines for control, and 8 for data.
the AY needs you to write a register and value to get sound out, the 8255 input can't do that.
So how does the sound get to the speaker?
Due to the lack of physical connection, I assume that the CPU is reading B7 and writing whatever is required to the AY. Do you have a dis-assembled version of the loading sequence we could look at?
Bryce.
hearing the "bit flow" from the tape was a nice way to find what you're searching "by hears"...
you know, those long beeps before the scratch Matrix escape crunch noise of the actual bit-stream...
But to be fair that's because when I last used tapes on my CPC6128... it was for a compilation of cracked games on a "big" tape, and I was just using my walkman with only the audio connected.
So I had to use ear and see the block on the screen to find the start of the games.
on 464PLUS, no sounds nor counter...
I guess Amstrad wanted peoples to have only original games with 1 game per tape.
Actually a clever way to somewhat get rid of those Cracked 60 or 90minutes tapes compilations. ;D
But I can understand how much a pain in the @$$ it is to add a counter or a mini sound system to it.
also, do you remember this application enabling to do samples from a tape... Ultrason I guess...
can it be used with an unmodified 464PLUS ?
perhaps not that good/practical if you can't hear directly what the Tape is reading.
Also could the DMA channels on the PLUS be exploited in anyway to get such kind of application even better ou a 464PLUS ?
Could be great to also have a jack plug on the casing for Audio-in only so you could use a modern MP3 or CD source to read/launch bits.
Ah... So on a 6128 with external tape player you hear the sounds too? That would prove that it's not leakage and IS being produced by the AY. The wire from the tape socket of the 6128 goes directly to B7 of the PIO and definitely isn't connected to anything else.
Bryce.
not sure actually, but i think so, if my memory is not altered by eons of beer and booze.
To simply use my walkman connected to my CPc6128 was cool anyway.
not sure it could work with protected game though.
If you load a tape on the 464 Plus and then set the TV volume full blast you can hear the bit stream, at least you can on mine. I always liked hearing the "loading music" I could hear the slightest deviation from ideal. I would usually spot an error before the CPC flagged it up, I used to load cassettes via the headphone socket on my Midi HI-FI (well we all had them in the 80s/90s) I actually just poked the bare wires into the cassette socket on my 6128 so I never even had a proper plug pushed into the socket lol! I remember the first cassette I ever loaded on my 6128 was Gemini Wing, I got it in a bargain bin at a local computer store for 25p! I was over the moon when it loaded via my crazy hack solution!
Quote from: Bryce on 14:42, 14 June 12
Ah... So on a 6128 with external tape player you hear the sounds too? That would prove that it's not leakage and IS being produced by the AY. The wire from the tape socket of the 6128 goes directly to B7 of the PIO and definitely isn't connected to anything else.
Bryce.
yes you do hear the sounds with a 6128 and an external player, but you only hear them well if you turn the volume high.
If you do that, the ay sound is far too loud and can get distorted.
BTW, I'm not buying the "AY is making the sound". I'm not going to change my mind on this. It doesn't.
I can't see how it does.
How could a pin on the 8255 cause the sound of the AY to be affected. The 8255 is physically seperate from the ay.
The AY is connect to the 8255 through other pins, and then it's only to control it.
Saying it affects the AY is the same as saying "when I put this input on this pin of the 8255, others magically change to send sound commands to the ay".
To affect the sound, the input from the tape needs to be piped through to the speaker, joining it with the AY sound, but not through the AY... it's not got audio in! (it's not a sid :laugh: ).
So I think the diagrams are not accurate:
http://www.cpcwiki.eu/imgs/b/b1/CPC_Disc_Cassette_Schematic.gif (http://www.cpcwiki.eu/imgs/b/b1/CPC_Disc_Cassette_Schematic.gif)
Something *is* missing.
Quote from: Bryce on 14:23, 14 June 12
Due to the lack of physical connection, I assume that the CPU is reading B7 and writing whatever is required to the AY. Do you have a dis-assembled version of the loading sequence we could look at?
Bryce.
http://www.cpctech.org.uk/docs/os.asm (http://www.cpctech.org.uk/docs/os.asm)
Look for this:
;; sample edge and check for escape
cpu is in a tight loop sampling the input.
BTW:
If you have a tape player connected *WITHOUT* motor control, and you turn up the volume, and you don't start the loading process. You can STILL hear it through the speaker.
It is also true if you just do this from basic:
out &f600,&10
So, leave it on Ready prompt, turn it up and listen... ;)
So now, where is the sound comming from??? ;)
I feel pretty sure from memory that the tape is connected to the SOUND pin on the expansion bus which is then connected to the amplifier and the internal speaker, on the 464 Plus I don't think this happens. The way I understood it, (over simplification follows...) is that the audio from the tape is fed to essentially, a noise gate, when the audio reaches a certain threshold the gate opens which the CPC interprets as a 1, when the audio falls back bellow the threshold, the gate closes, which is interpreted as a 0. This is why, when you play an audio tape, for example Nirvana, Smells Like Teen Spirit. You get a horrible distorted version played through the CPC. This is because the audio is essentially triggering a switch that lets through, say +5v. Its like a 1bit sample rate, basically one level of quantisation (on off).
I wasn't suggesting that the analogue signal is magically getting sent to a non-existant analogue input on the AY. I was suggesting that the CPU (which is reading the 0s and1s at B7 of the 8255) is running a small routine to tell the AY to play note X when a 0 is read and play note Y when a 1 is read. The reason for this conclusion is the schematics, which as you can see below (this time the 6128), the wire from the tape port goes directly to the 8255 input B7. It's not (according to the schematics) connected to anything else and has no direct route to the speaker.
The "noise gate" you describe is the part I called Op-Amp B in the diagram above. If I get time at the weekend, I'll open up a 464 and a 6128 and check if there are any connections there, that are not on the schematics. Last night while doing some more of the 464+ mod (the original theme of this thread :D ) I found several errors in the schematics and the BOM.
Bryce.
Quote from: Bryce on 09:18, 15 June 12
I wasn't suggesting that the analogue signal is magically getting sent to a non-existant analogue input on the AY. I was suggesting that the CPU (which is reading the 0s and1s at B7 of the 8255) is running a small routine to tell the AY to play note X when a 0 is read and play note Y when a 1 is read. The reason for this conclusion is the schematics, which as you can see below (this time the 6128), the wire from the tape port goes directly to the 8255 input B7. It's not (according to the schematics) connected to anything else and has no direct route to the speaker.
The "noise gate" you describe is the part I called Op-Amp B in the diagram above. If I get time at the weekend, I'll open up a 464 and a 6128 and check if there are any connections there, that are not on the schematics. Last night while doing some more of the 464+ mod (the original theme of this thread :D ) I found several errors in the schematics and the BOM.
Bryce.
@Bryce: The CPU doesn't do what you suggest.
There is nothing in the loading/saving which does this.
What I would like to know on a cpc is the SOUND on the expansion, does it have tape noise or not?
It is possible it doesn't, and that only the speaker has the extra connection.
As for the errors in the schematics it would be great, when you have time to correct them.
This discussion is quite interesting to me. Personally I hate the silent load of my 464+ and actually put extra effort in to route tape read and write noise into my sound output on my FPGA emulator - because that's what a real CPC does as far as I'm concerned!
I just find it practical to be able to hear the audio.
About the audio being sent to the CPU or not, I don't think so either. Because if you put any normal audio tape with music in the player, you can hear that too coming out the speaker
Quote from: arnoldemu on 09:38, 15 June 12
@Bryce: The CPU doesn't do what you suggest.
There is nothing in the loading/saving which does this.
What I would like to know on a cpc is the SOUND on the expansion, does it have tape noise or not?
It is possible it doesn't, and that only the speaker has the extra connection.
As for the errors in the schematics it would be great, when you have time to correct them.
To be honest, I didn't really think it did, but as I said, the schematic also doesn't show how the sound gets there either. I'll try to find time to rip open a 464 at the weekend and find out exactly what's connected to what and how the sound is getting to the speaker.
Regarding the errors, I didn't write them all down. The only one I can remember is that R106 in the 6128+ BOM is listed as a 1.5Ohm resistor, when in fact it should be 1.5KOhm. I know this because I ordered the parts for the mod from the BOM and now I have to go and order this part again. 1.5K (or even 1.5Ohm) is not a standard (preferred) resistor value, so it's not a resistor I'd normally have lying about :(
Bryce.
I have had a brief mess around with a multi meter and the mainboard from a 6128 and the only tape associated signal I can find that is connected in any way to the CPC audio amp is the Data Out pin. I think Bryce is quite right that the AY is producing the signal we hear on a classic CPC while loading. The AY is particularly good at producing Square Waves, and it is quite possible that an error in the source audio from the cassette could be reproduced as the signal produced by the AY would be directly correlated to the source audio. How faithfully the error is recreated would depend on the baud rate which I believe can be around 2000 bits/sec this would seem adequate to me.
The reason why music played through the system seems quieter and very degraded is most likely due to the CPC only being interested in a Unipolar signal, the CPC only needs to make a distinction between Off and On or Loud and Quiet. A Music signal would essentially be cut in half, causing it to become half as loud, hence having to turn the volume up to hear it. Also the baud rate would be adequate to produce the horrible version of whatever 80's classic tape you happen to try to play through it. :laugh:
Ok, I just did a full tape loading investigation, here's the result:
1) There is no direct (intentional) connection between the tape output and the speaker.
2) The loading sound in the speaker is definitely unintentional and not designed to be that way.
3) The problem is definitely "solved" on the 464+
4) The AY is not producing the sounds.
I measured the output of the AY while a tape was loading, it's zero. The only physical connection between the tape output and the sound amplifier is a +5MOhm path, which would definitely not produce any sound on the speaker. The effect happens because the classic CPC has shared an Op-Amp chip for the tape amplifier and the sound amplification. Referring back to the diagram I posted on the previous page, Op-Amps A + B which amplify the tape head output are in the same IC package as Op-Amp C which is the pre-amp for the sound. There is cross-talk between these Op-Amps, which then gets exaggerated by the fact that it's a pre-amp and is amplified further after the volume switch. The 464+ doesn't use Op-Amp C for the sound circuitry. the output of the AY on the 464+ is pre-amplified by two transistors and goes directly to the audio-out (at Line-out levels). Also, the entire amplification on the classic CPC happens on the tape-deck PCB, but on the 464+ it happens on the mainboard.
I can add a small Op-Amp (or maybe even use the un-used stage) on the 464+ to create the sound on the 464+ if you like. I also looked at adding a counter: Not a chance, the space just isn't there.
Bryce.
Edit: There's a very easy way to prove this... Disconnect the Data-Out pin on the cassette player, so no data is making it to the mainboard (or the AY), then load a tape... The sound is still heard in the speaker.
Quote from: Badstarr on 22:23, 15 June 12
I think Bryce is quite right that the AY is producing the signal we hear on a classic CPC while loading.
However, that
isn't what's happening. For example, try this (it's writing to tape) clearly with no AY involvement:
10 OUT &F600,&10
20 OUT &F600,&30
30 GOTO 10
The relevant part of the schematic is on the 6128 page entitled "disc control interface", bottom right in the "cassette control circuit" (maybe page 36).
For tape output, pin D is connected to tape pin 5 (MIC), which also goes via R310 and R308 to the sound amplifier circuit above (R304 goes from that point to the op-amp input).
For input, pin E is connected to the opamp that goes to the PIO, but before that, tape pin 4 (EAR) is connected via R311 and R308 to the same circuit above.
On page 20, you can see how pins E and D are connected directly to the PIO, pins 25 (E tape input) and 12 (D tape output) respectively.
Quote
The reason why music played through the system seems quieter and very degraded is most likely due to the CPC only being interested in a Unipolar signal, the CPC only needs to make a distinction between Off and On or Loud and Quiet.
Effectively, yes - it's because it's been squished through the opamp to make it 0 or 1 rather than analogue, but not because the CPC has sampled and replayed it.
Quote
Also the baud rate would be adequate to produce the horrible version of whatever 80's classic tape you happen to try to play through it. :laugh:
This is unaffected as the op-amp is "practically" instantaneous.
Quote from: ralferoo on 13:52, 16 June 12
For tape output, pin D is connected to tape pin 5 (MIC), which also goes via R310 and R308 to the sound amplifier circuit above (R304 goes from that point to the op-amp input).
For input, pin E is connected to the opamp that goes to the PIO, but before that, tape pin 4 (EAR) is connected via R311 and R308 to the same circuit above.
The connection via R308 is the 5V power supply to the Op-Amps, not a signal connection, if the sound passed through here, then the tape deck wouldn't work. C316 (between R308 and R310) is there to guarantee that nothing analogue makes it from R310/R311 to R308.
Bryce.
Hmm... So the loading sound is essentially an accident? If it is then it's a good one to make, I for one like the reassuring whistles and whines while a tape loads as I'm sure many of us here do. Congratulations on solving the mystery Bryce! Having poked around on the 6128 mainboard and not being able to find a definite link to the CPC speaker I felt sure that your theory about the AY was the most logical/likely explanation. Mind you, I see no real reason why the AY theory couldn't also work in practice, you never know maybe a similar system was contemplated at some point in the CPC design. Perhaps its a little too complicated and over engineered in reality. However it may be the sound engineer in me that likes this solution as its sort of sampling, but not, using the signal produced by the cassette to produce a a clean synthesised counterpart using another device. It kind of makes me imagine it as a way of streaming samples, I dunno, my brain comes up with these sorts of ideas occasionally and sometimes they actually work :laugh:
Quote from: Bryce on 15:59, 16 June 12
The connection via R308 is the 5V power supply to the Op-Amps, not a signal connection
Ooops, good spot!
Quote from: Badstarr on 18:28, 16 June 12
Hmm... So the loading sound is essentially an accident? If it is then it's a good one to make, I for one like the reassuring whistles and whines while a tape loads as I'm sure many of us here do. Congratulations on solving the mystery Bryce! Having poked around on the 6128 mainboard and not being able to find a definite link to the CPC speaker I felt sure that your theory about the AY was the most logical/likely explanation. Mind you, I see no real reason why the AY theory couldn't also work in practice, you never know maybe a similar system was contemplated at some point in the CPC design. Perhaps its a little too complicated and over engineered in reality. However it may be the sound engineer in me that likes this solution as its sort of sampling, but not, using the signal produced by the cassette to produce a a clean synthesised counterpart using another device. It kind of makes me imagine it as a way of streaming samples, I dunno, my brain comes up with these sorts of ideas occasionally and sometimes they actually work :laugh:
I would guess that the engineers noticed the mistake during the prototype test phase, but then decided it was actually quite cool, so they chose not to solve it. Just a pity they didn't use a similar solution on the plus. For some reason (most likely cost) they decided that the plus wouldn't have an internal speaker. To be honest, it probably did save them a fortune.
Bryce.
Anyway, nice to see this aspect of the CPC and this particularity of having an internal speaker has just been studied.
and yes, it was a kool "feature".
Quote from: Bryce on 13:33, 16 June 12
The effect happens because the classic CPC has shared an Op-Amp chip for the tape amplifier and the sound amplification.
So I was correct? ;)
leakage/cross talk.... ;)
There was a story that the original CPC had a design fault whereby the square wave produced when writing to tape was not correct. The firmware was coded to cope with it.
The problem was spotted by an engineer in the east and corrected. When the machine got back they had to modify the software to make it work. :laugh:
Quote from: Badstarr on 18:28, 16 June 12
Hmm... So the loading sound is essentially an accident? If it is then it's a good one to make, I for one like the reassuring whistles and whines while a tape loads as I'm sure many of us here do. Congratulations on solving the mystery Bryce! Having poked around on the 6128 mainboard and not being able to find a definite link to the CPC speaker I felt sure that your theory about the AY was the most logical/likely explanation. Mind you, I see no real reason why the AY theory couldn't also work in practice, you never know maybe a similar system was contemplated at some point in the CPC design. Perhaps its a little too complicated and over engineered in reality. However it may be the sound engineer in me that likes this solution as its sort of sampling, but not, using the signal produced by the cassette to produce a a clean synthesised counterpart using another device. It kind of makes me imagine it as a way of streaming samples, I dunno, my brain comes up with these sorts of ideas occasionally and sometimes they actually work :laugh:
I believe the Enterprise computer uses the sound chip to write cassette data.
Nice way to re-use some electronics.
Quote from: Bryce on 22:38, 16 June 12
I would guess that the engineers noticed the mistake during the prototype test phase, but then decided it was actually quite cool, so they chose not to solve it. Just a pity they didn't use a similar solution on the plus. For some reason (most likely cost) they decided that the plus wouldn't have an internal speaker. To be honest, it probably did save them a fortune.
Bryce.
I was thinking they had cut it out because of the lack of internal speaker. Imagine tape loading noise being amplified through the monitor/television. Ouch!
Quote from: arnoldemu on 09:16, 18 June 12
So I was correct? ;)
leakage/cross talk.... ;)
Yes you were correct. The reason I questioned it being a leak is because it is so consistant. Leaks normally vary their pitch and volume and can be easily effected by other sources too. But because the leak seems to be inside an IC, everything is pretty consistant.
Bryce.
This is truly an interesting discussion. Imagine that, a mystery just solved in 2012? Wow.
Now waiting for the simpler explanation. I'm barely following Bryce's story, but as soon as I'm done I'm left with only the general idea. Maybe it's the lack of sleep from last night's elections...
Anyhow, didn't other systems have loading sounds?
Quote from: Gryzor on 15:19, 18 June 12Anyhow, didn't other systems have loading sounds?
I remember finding it a bit frustrating there weren't any loading sounds on my mates C64 back then. Asked him how he knew where a game began on the tape. He replied: "You can see it on the colors on the screen".
It's been a while since I have used one but I seem to remember the Spectrum had loading sounds, I would imagine that, based on the Spectrum (ehem) build quality, that this would have been a simple pass through from the cassette to the modulator.
I maybe being a little unfair to the Spectrums build quality but in my experience they aren't the most robust of machines even the Amstrad versions were a poor comparison to the CPC. I briefly had a Spectrum+2 (sort of anyway, it was given to me and my sisters by my Dad) I remember the horror as I pressed the play key one day and it snapped off. Of course I was told I was too rough with it! Strange then that my 6128 is still fighting fit after 20 years! Another one of those trips down memory lane that these topics tend to inspire. :laugh:
Quote from: Badstarr on 08:40, 19 June 12
It's been a while since I have used one but I seem to remember the Spectrum had loading sounds, I would imagine that, based on the Spectrum (ehem) build quality, that this would have been a simple pass through from the cassette to the modulator.
The Spectrum solution was a stroke of genius. It's actually a single pin on the ULA used for BEEP, EAR and MIC and connected to all 3 differently. It produces different voltages according to which logical bit is fiddled with by the CPU, but pretty much they can be interchangable as they're not massively different.
Incidentally, if you're interested in such things, this book on the reverse engineering of the Spectrum ULA is a fantastic read: The ZX Spectrum ULA: How to design a microcomputer (http://www.zxdesign.info/book/)
Quote from: mr_lou on 15:43, 18 June 12
I remember finding it a bit frustrating there weren't any loading sounds on my mates C64 back then. Asked him how he knew where a game began on the tape. He replied: "You can see it on the colors on the screen".
Tell me about it... I finally got a tape game, The Sentinel, on Monday for the C64 I bought a few weeks ago and never having used a C64, I wasn't sure if the thing was working or not until the tape ran out and I was still looking at a blue screen. Those old Amstrad tape loading sounds were reassuring...
Even by mistake, Amstrad did the right thing it would seem :D
This morning the last parts arrived for stage one of the 464+ Mod. The 464+ has finally grown up and become a 6128+.
The µPD765 Floppy Controller, SED9420 Data Separator, Extra RAM, Floppy Logic ICs, Floppy header / power / filter, External Floppy Connector and lots of other passive components have been added. All new ICs are mounted in sockets to make any future repairs easier. I've just tested the additional RAM and even loaded its very first program from disc. All is working fine. Now it's time to look at what additional stuff can fit inside the casing...
Bryce.
P.s. If anyone else is considering doing the same upgrade, I have a small stock of the hard to find µPD765 / SED9420 etc.
Nice! :)
good work Bryce.... :D
I'm interest in the same mod (ram+floppy controller)...
I send you a pm for info...
Details are in amstrad action issue 90 (ram) and 91 (disk controller).
Bryce this is shaping up to be a fantastic 464+ mod and really shows your engineering skills in action! I'm looking forward to watching your progress and more of the insights into the internal workings of the machine that you will no doubt discover along the way! Keep up the great work!
Quote from: steve on 11:05, 24 June 12
Details are in amstrad action issue 90 (ram) and 91 (disk controller).
Where find they? Megaupload link in cpc wiki section is out... of course...
edit: I have find all issue, but the scan quality is not very good
http://archive.org/search.php?query=collection%3Aamstrad-action-magazine&sort=-publicdate (http://archive.org/search.php?query=collection%3Aamstrad-action-magazine&sort=-publicdate)
if you have good quality please snd me a pm
Quote from: emilen72 on 12:10, 24 June 12
Where find they? Megaupload link in cpc wiki section is out... of course...
edit: I have find all issue, but the scan quality is not very good
http://archive.org/search.php?query=collection%3Aamstrad-action-magazine&sort=-publicdate (http://archive.org/search.php?query=collection%3Aamstrad-action-magazine&sort=-publicdate)
if you have good quality please snd me a pm
Obviously you've missed the Downloads section above ;)
Quote from: Gryzor on 18:37, 24 June 12
Obviously you've missed the Downloads section above ;)
Obviously of course... ;D
Gryzor many thanks
I'll be making a proper Wiki page detailing the entire conversion as soon as I have time.
Bryce.
Quote from: emilen72 on 23:13, 24 June 12
Obviously of course... ;D
Gryzor many thanks
My pleasure :)
@Bryce: thanks, much appreciated. Not that you need it, but if I can be of any assistance...
Hi All,
I managed (without Gryzors assistance :) ) to create a Wiki page with some more details on how to convert the 464+ to a 6128+ (PCB and Electronics only for now). You can find it here: 464Plus Conversion - CPCWiki - The Ultimate Amstrad CPC Community & (http://www.cpcwiki.eu/index.php/464Plus_Conversion)
Bryce.
An excellent article, realy enjoyed reading that. I was thinking of having "feature" articles in the front page, this is a great candidate...
Yeay Bryce...
Nice page...
Yet.
Perhaps you should have aimed at a more generic page like : "completing the PLUS Mainboard".
Such page would/should also tell how to turn the 6128 into a Tape able machine...
Also the 8bit printer port while at it ?
I know the CPCwiki aim at more pages, but having some of them mixed can be great. ;)
I have a fair few of the resistor networks, can't remember how much exactly but I know I have a sample tube at least half full. If anyone attempts this mod and would prefer not to make the resistor network themselves let me know (although, to be honest if you are competent enough to perform this mod then you probably don't mind making your own).
Quote from: Gryzor on 19:10, 15 July 12
An excellent article, realy enjoyed reading that. I was thinking of having "feature" articles in the front page, this is a great candidate...
Sound like a brilliant idea. Would be nice to also include the hybrid Badstarr is working on when it's finished; have you made any more progress on it after your cat tried destroying it?
I have made a little progress I'm saving the brunt of the work for when I'm on holiday, the expansion port (the connections to the ASIC) are all restored thankfully, however I occassionally find it jumps the f1 f2 menu which is down to I believe, an as yet undiscovered loose connection somewhere. I think it's most likely on the expansion bus as fiddling around with it makes the problem vanish. No biggie, as I'm using a slightly unique expansion port solution (not really very exciting and will no doubt be a little controversial lol!) which will mean reworking this part so no doubt I will correct the problem.
Other than that I managed to spend a little time on the MegaFlash just need to wait for one more IC and connect a few more bits and bobs. Then I will need to have a good think about how I will be designing the cartridge system, which will work like an overgrown ACID Inside/MultiCart, I would like to cram as much as possible into this machine!
Quote from: MacDeath on 21:10, 15 July 12
Perhaps you should have aimed at a more generic page like : "completing the PLUS Mainboard".
Such page would/should also tell how to turn the 6128 into a Tape able machine...
Also the 8bit printer port while at it ?
I know the CPCwiki aim at more pages, but having some of them mixed can be great. ;)
I agree that we need articles about these additional mods, but putting them all on one page makes it rather confusing. People might get the impression that you need to do all of these changes or it will not work, or they just want to make one of the mods and would have to filter out what they need. When the other Guides exist, they could be grouped under one "CPC+ mods" heading or whatever, but I don't think putting everything on one page is good.
And I don't think page count is an indication of content quality, so I am not just saying that so that there are more pages.
Bryce.
I totally agree with Bryce, it's not logical to put everything in one page. If it was, then we should have maybe 3 or 4 pages on the wiki :D It's not a matter of having more pages either, 4000+ pages is already more than enough (the c64 wiki (http://www.c64-wiki.com/index.php/Main_Page) only has 800-odd articles and it's still very good!).
Now, who's for resurrecting the official FAQ? What? off-topic? Oh well...
*push
How's the project going?
Due to extreme lack of time, not much has happened. Hopefully I can get some time to work on the 512K RAM expansion this weekend. The HxC has also arrived, so I might install it too.
Bryce.
Quote from: Bryce on 14:04, 25 August 12Due to extreme lack of time, not much has happened. Hopefully I can get some time to work on the 512K RAM expansion this weekend. The HxC has also arrived, so I might install it too.
Luckily, there's no rush with this project. :)
Quote from: Bryce on 14:04, 25 August 12Hopefully I can get some time to work on the 512K RAM expansion this weekend.
Great! :)
I had time to build the S-Video output today, but no time to install it yet :( Tomorrow my plan is to build the USB mouse port, then install both at the same time and possibly even install the internal expansion port?
Bryce.
Hi again,
I didn't manage to get the USB Mouse done today, but I decided to work on the casing instead. These are the first cuts done to the case. As you can see, the 464 now has its very own floppy port (later with ABBA switch) and the socket on the left is the S-Video port. The lid of the tapedeck actually hits the floppy connector, so a small corner of the hinge (inside, nothing visible) needed to be removed.
Bryce.
Here's what it looks like inside. The S-Video PCB fits nicely under the tapedeck, but the filter (that thing with the red coils of wire) is interfering with the write protection pin of the tape recorder, so I'll need to move it slightly.
The S-video PCB is mounted using two screws from below, so there's no visible screws and it's pretty robust.
Bryce.
Very nice! :)
very good integration !!
I want need one of these...
Why would you want a half finished computer?
Anyway, next up is the USB port and internal MegaFlash. Coming hopefully at the weekend.
Bryce.
Because then I could/would ship it to you to finish it (including a dual 8MHz accelerator).
Question: Isn't that a magnet on the floppy-port with the red wire wrapped around it? Isn't that rather close to where the tape will be? Doesn't that partially erase what's on the tape?
Now this is a most awesome project!
thanks for sharing =D
Quote from: mr_lou on 17:32, 13 September 12
Question: Isn't that a magnet on the floppy-port with the red wire wrapped around it? Isn't that rather close to where the tape will be? Doesn't that partially erase what's on the tape?
Don't worry, it's not a magnet, it's a ferrite core, ie: It's made from ferric metals, but it's not magnetised. It has no effect on tapes.
Bryce.
Quote from: mr_lou on 17:32, 13 September 12
Question: Isn't that a magnet on the floppy-port with the red wire wrapped around it? Isn't that rather close to where the tape will be? Doesn't that partially erase what's on the tape?
Nah, Bryce has done cloud integration.
Yeaaaa, long weekend and no-one home... Time to get things done on the 464+ Mod.
This time it was time to install the HxC. I'd been leaving this for a quiet moment without interruptions because cutting holes in original hardware is a thing you don't get to try twice. Either it's right the first time, or it's messed up. MrLou wanted the HxC to be as discrete as possible. The only place the PCB would fit with external access to the SD Card is if it faces out the back. This unfortunately means that the HxC Board needs to magically float above the centre of the CPCs PCB at exactly the right spot. To do this, some serious mechanical modding was required. By a huge stroke of luck, the mounting holes on the HxC for the LCD are exactly the same distance apart as the 50way Centronics screws. So first I replaced those screws with longer ones for my brackets. Then I made the brackets. These are made from brass U-shaped rods, very useful for modding as they are relatively soft (easy to drill and shape) yet rigid enough to support the PCB. The HxCs height was later adjusted by adding spacers underneath (which were required anyway to ensure the bracket doesn't short anything on the HxC).
The slit at the back is the difficult part. You only get one chance to get it right. Luckily I got it right :) When the SD Card is inserted it now peeks a mere 2mm out the back, enough to insert and remove, but discrete enough to not be obvious. The HxC will be controlled from a ROM on the MegaFlash, so no LCD will be installed, the LEDs will be mounted on the top of the case and some very small buttons on the side will be also available if/when required.
Now it's time to install the internal MegaFlash, more pictures later....
Edit: Just added another picture, where you can see it with the power and data cables attached (and SD Card inserted). The data cable is custom made to fit exactly under the HxC with a fold to keep things neat. The power cable is also routed under the HxC.
Bryce.
P.s. @MrLou: I didn't have to remove the mounting screw for the PCB as I thought earlier, so the PCB and CPC case still has all it's original mounting screws :)
Awesome amazing work!!! It looks perfect! :) :) :)
Moving swiftly along... I've now created the internal Expansion Bus. This isn't technically difficult, but it's a serious pain in the arse and takes ages, because you have to separate, strip and solder each of the 50 wire individually.
To make sure that no short-circuits can occur I also prepared the PCB by cutting off any protruding pins on the bottom of the board, that might poke through the cables insulation. Then I bent the 50 pins at an angle to make soldering easier. After that it's just the slow and painful job of stripping and soldering each wire in place. The flat cable also needs to be split in the centre to allow the PCB mounting screw to pass through. A little origami is also required under the board to get the cable to come out at the correct point, but there's enough space underneath to comfortably fit the folded cable. Then I crimped a 50 way connector on and gave it a test with one of my own MegaFlashes.
I've built a custom MegaFlash for this project, with a header for all the switches and LED, so that they can be mounted on the case, but this one obviously won't work yet when no jumpers are in place. The extra flat cable will remain as it is to allow further internal expansions to be added later. The MegaFlash easily fits under the left side of the keyboard and there's still lots of space free.
Enjoy the pictures.
Bryce.
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Serious wow.
Can I have mine with an afterburner, please?
Else, can you put all this in a wiki article when it's over, for us paupers?
T
PS The distance between the screws coincidence reminded me of the distance of car wheels compared to ancient carriages :D
As I was on a roll and enjoying the mod, I did another bit today. This time it's the USB AMX Mouse interface. The PCB is built, but it needed a USB port on the case. It's a very tight fit at this stage behind the tape deck. I had to snip quite a bit off the USB connector to get it to fit without disturbing the tape lid or tape mechanisms. So now the back of the CPC looks like this:
[attach=2]
All 3 of the ports you can see here are new (ie: added for this mod). From left to right you can see the USB mouse Port, S-Video Port and External Floppy Port, none of which were on the original 464+ :)
That's it for today, off for a well earned pint now :)
Bryce.
P.s. The Floppy port looks a little off line in the picture because the PCB isn't screwed in place, I just put it together temporarily for the picture.
Imagine the bidding war if this ever reaches eBay...
Quote from: Gryzor on 20:13, 03 November 12
Imagine the bidding war if this ever reaches eBay...
It will never reach eBay. ;)
Well... maybe some day in 50 years when I've passed away and my daughter don't know what to do with it.
Yeah, I know you wouldn't, not implying anything :) But, mortal coil and all... :D
If I ever need to make my hobby into my job, then I'll buy up a few CPCs, mod them to the limit and put them on ebay. But the time and expense needed to do something like this, means that I probably won't get very rich from it :(
Bryce.
As MrLous top priority is to keep things discrete. I've had a change of plan regarding the switches. I will try to mount the less frequently used switches underneath the CPC. As you can see from the picture below, there is a triangular indentation approximately 12mm deep on either side of the case (where the fake cooling slots are). I need to measure how much space is available inside when the keyboard is in place, but it's looking promising so far.
Bryce.
Ok, so things went to plan. The switches for the MegaFlash are hidden under the CPCs Keyboard :)
As you can see from the pictures, it was a tight fit inside, I only have about 1mm clearance and that's after I trimmed the switch terminals. For the slider switch I just expanded one of the fake cooling slits to allow the slider through.
[attach=2]
The slider switch is the Read/Write switch for the MegaFlash. I chose the slider because it's not a switch you would want to accidentally switch to the wrong position. The two toggle switches are to enable/disable ROMs 0 and 7 on the MegaFlash.
[attach=3]
Under the CPC there is about 1mm clearance from the desk to the toggle switches. But you can actually switch them without lifting the CPC if your fingers aren't too fat. :D
[attach=4]
The on/off switch for the AMX Mouse will also be a toggle switch, but I'll put it on the other side. Then I just need to mount the LEDs and wire it all up. The mod is almost finished, I can see a tunnel at the end of the light :D
Bryce.
Nice work! :)
Such a heavily modded machine should have all the switches, knobs, dials and screens where you can see them. And maybe add a boiler so it can release some steam when you perform an operation ;)
That's how I like it too, but MrLou is the customer and he prefers understatement. It will still be an unbelievably cool machine.
Bryce.
(http://www.cpcwiki.eu/forum/index.php?action=dlattach;topic=6891.0;attach=5537;image) (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/464-mod/?action=dlattach;attach=5536;image)
How cute.
(http://www.cpcwiki.eu/forum/index.php?action=dlattach;topic=6891.0;attach=5547;image) (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/464-mod/?action=dlattach;attach=5546;image)
How even cuter.
Loads of great ideas I guess.
What about a plug for modern audio jack for the tapes ?
and/or in-built iPod base... :D
At the weekend I'm hoping to get the last few tasks finished. Here's the list of what's left:
Test the MegaFlash.
Mount and connect the AMX Mouse PCB (under the centre of the keyboard)
Mount and wire the HxC buttons.
Mount and wire the LEDs (5x)
The mods require 5 LEDs in total: 3x for the HxC, 1x for the AMX Mouse, 1x for the MegaFlash. To keep things dicrete, it has been decided to put all these buttons / LEDs on the side surface, where the Floppy would be on a 6128+. So the final result should look somethiong like this:
[attach=2]
Excuse the crap mock-up.
From the front of the CPC, it should be barely noticable that the machine is anything but the original. Except for the SD card at the back, there'll be no noticable changes.
Bryce.
But you drew 7 LEDs?
Anyhow, I know he wants it discreet and all, but what's the point of a LED if you can't see it from a normal operating position?
Quote from: Gryzor on 13:59, 09 November 12Anyhow, I know he wants it discreet and all, but what's the point of a LED if you can't see it from a normal operating position?
Placing them on the side means they're not annoying my eyes. And if I need to check what's going on, I can just skew to the right. Perfect solution for me.
The LED in the two HxC's I have at the moment, are very annoying.
Quote from: Gryzor on 13:59, 09 November 12
But you drew 7 LEDs?
Not unless someone invented black LEDs while I wasn't paying attention? :D The top 5 are the LEDs, the bottom 2 are the HxC buttons.
Bryce.
Quote from: Bryce on 14:28, 09 November 12
Not unless someone invented black LEDs while I wasn't paying attention? :D The top 5 are the LEDs, the bottom 2 are the HxC buttons.
Bryce.
I've got this design for a black led.... ahem.
Cool, just imagine what could be made with this, especially if we put it together with my "Bi-directional diode" (Patent Pending) :D
Bryce.
Quote from: Bryce on 15:05, 09 November 12
Cool, just imagine what could be made with this, especially if we put it together with my "Bi-directional diode" (Patent Pending) :D
Bryce.
"you wanted the current in one direction, but we went one better".
Quote from: Bryce on 14:28, 09 November 12
Not unless someone invented black LEDs while I wasn't paying attention? :D
OMG! I tried them out, just switched one of them on, and immediately eveything was dark! So I stept on a C64 on the floor ;-)
I hope you were able to wipe it off your shoe. I hate when I step in things like that :D
Bryce.
Small update:
I didn't have all that much beer last night, so the hands were steady enough to get some case drilling done. Time to mount the buttons and LEDs. The control panel is made from a few pieces of vero-board. The flat cable will have a connector on the end to make it a bit easier to open or remove the upper case.
[attach=2]
I had to keep the buttons and LEDs pretty compact, because there is a stabilising strut right in the middle of the area where the buttons and LEDs should go. Not only did I not want to remove this for stability reasons, but I could even use it to my advantage to mount the panel without any externally visible signs.
[attach=3]
The panel is held in place by two screws in the strut.
[attach=4]
As these buttons will probably get a lot of use, they need to be pretty solidly mounted.
[attach=5]
From the outside you just see buttons and LEDs. The three buttons and first three LEDs are for the HxC. The red LED is for the MegaFlash (write-mode) and the last green LED is for the USB AMX Mouse.
Bryce.
P.s. The beer can in the first picture is for Gryzors benefit :)
Hi All,
this weekend I had the rare situation of two full days of CPC hardware time! So I wasted no time and managed to finish the 464+ mod! So here it is (sorry picture is a bit blurred, I need to make a better one):
[attach=4]
For those who haven't being paying attention, here's a summary of what's been done. Starting from the top left you can see the internal HxC with the SD Card that protrudes out the back (If Jeff or Lotharek are reading this: Sorry, I had to seriously canabalise the HxC to allow external LEDs etc). This floats above the main PCB on two brackets mounted to the Centronics port. Below that you can see the floppy controller components that were added to make this possible. Beside them are of course the extra 64K (hidden under the floppy cable). On the right above the tapedeck you can see the new external floppy port and the S-Video converter. The USB Port (for the mouse) is right beside the S-Video port, but it can't be seen in this picture because it's actually mounted in the top half of the case. On the right hand side of the tapedeck is a header mounted on the tapedeck frame that supplies all the connections needed for the buttons and LEDs, this makes opening and servicing the CPC slightly easier. There's 18 wires needed for the buttons and LEDs and 4 for the USB port, all of which are on the upper half of the case, a nightmare to open if you don't have a connector. Under the keyboard are the MegaFlash on the left and the AMX Mouse adapter in the centre. There is also a further possibility to add another expansion (extra RAM or whatever) under the keyboard.
[attach=2]
As requested by the owner, everything has been done extremely discretely, so that from the front of the CPC, there's barely any sign that anything has been changed.
[attach=3]
Of course, from the back you can see all the new ports: USB Mouse, S-Video, external floppy and the SD Card peeping out above the expansion port. The HxC Buttons and LEDs and the MegaFlash and AMX Mouse LEDs can be seen at the side and underneath there are switches to switch the AMX Mouse on/off, MegaFlash Read/write and to enable/disable ROMs 0 and 7 of the MegaFlash. Even with all this stuff packed inside, the cartridge slot, all existing ports and even the tapedeck are all still fully functional. I think I can safely say, that this is one cool CPC. I'm almost sorry to have to put it in the post. But first I will spend the next week testing everything to the limit, to make sure that everything works as expected.
Bryce.
Brilliant stuff. I've barely even seen the Plus range in the past, but they're very nice-looking machines. Especially, I must say, when you know that they've been upgraded inside to such an extent as this! :D
I just have to keep telling myself that I don't need to pay anyone to do things like this for me, because the only things I need to get are an external HxC and a SCART lead. Must stop self from thinking about all the other possibilities... Must! Stop!
It's tempting, but to be honest (hard to believe), most of my retro computers are completely original and mod-free, I use a few external expansions, but I rarely integrate stuff. I don't even own or use some of the expansions I've designed :D
Bryce.
Very nice! mr_lou is a lucky chap!
When are you taking orders for the 512k version with HxC screen built into case? ;)
Personally, I would have done a few things differently, including putting a display on the HxC, but it's not my computer, MrLou wants to use the HxC Browser and no display. The 512K RAM might come later, there's still space inside for it.
I ran a few tests last night just to check the basic functions:
Extra RAM - Works
Disk Controller - Works
Tape loading - Works
MegaFlash - Read and Write - Works
AMX Mouse - Works
S-Video - Works
External Floppy port - Works
I have a question about the function of the HxC, maybe someone here can tell me. When I am using the HxC ROM software, I've configured the SD Card as required (Autoboot Config File and Autoboot.hfe installed). I was kind of expecting the thing to autoboot to something, but it doesn't. Is this because the Plus blocks it with the annoying F1/F2 menu? Or what exactly should happen differently. Up to now I've only ever used the HxC with a display.
Bryce.
It does look very nice as it is :D
Sorry I can't help with the menu thing, I bought my 6128+ with a hacked Parados cart which I use with my 6128+, HxC and Megaflash :(
Damn I'm jealous. If it wasn't for the poor CPC I'd hope for the thing to get lost in the mail :D
Bryce, this post is amazing, really good job, it looks like that is what it should look like originally!
Would be good to have photo side by side of before and after of the back, I've never seen a cpc+ before ::)
Quote from: Bryce on 15:11, 17 November 12
From the outside you just see buttons and LEDs. The three buttons and first three LEDs are for the HxC. The red LED is for the MegaFlash (write-mode) and the last green LED is for the USB AMX Mouse.
What do the buttons do?
From the website by the manufacturer (note: not designer) of the HxC (http://lotharek.pl/product.php?pid=13):
QuoteUser Interface:
- 3 LEDs ("Power LED","Floppy access LED"," SDCard access LED ").
- 3 buttons ("Next","Select/Eject","Previous").[/l][/l]
[/list]
So how would you actually load a program from the SD card?
The SD Card is loaded with HFE files. Each one is a virtual copy of an entire floppy disk. With the Next/Previous buttons you can scroll through the files (and sub-directories if you've sorted them that way) and the HxC will mount/un-mount the current file when you click select. As soon as a virtual disk is mounted, the CPC "sees it" as a normal disk in a normal drive (A or B depending on how it's installed / setup. So CAT / Load / RUN etc works as normal.
Bryce.
I think you're forgetting the intermediate step: the SD card is mounted on the HxC floppy emulator we've been talking about, Lynwen. Bryce's instructions[nb] can you really do directories with the buttons? Didn't remember that!![/nb] apply to the HxC.
Oh yeah, I kind of assumed we were talking about how to access files on an SD Card using a HxC.
Yes, pressing the select button when you are on a sub-directory enters that sub-directory. Pressing select on the "." file goes back out to the parent directory. I use A,B,C.... Directories to sort my games disks :)
Bryce.
Makes sense, it's only that I go the software way to access subdirs...
Shouldn't be a problem to use the HxC as kind of 'floppy speed' like hard disc, it seems to work for ST.
That is actually a brilliant use of the HxC on the ST; have been meaning to try it out, but no time... :(
You can do what now with the ST? I've just used a HxC in place of the floppy drive....
Oh yes. Check this:
HxC mount (http://hxcmount.atomas.com)
QuoteHxCmount is a piece of software for your Atari ST that transform your HxC Floppy Emulator SD card into a hard disk emulator. Once loaded, you will be able to use a new disk letter (C: for example) exactly as a hard disk partition, the only thing is that the partition resides on a image file on your SD card.
Seriously cool!
Hi Bryce if there is no LCD screen to tell the user what is currently selected how do they know what buttons to press (previous next select) or am I missing something?
Hi, you can use a software solution. For the CPC there is a ROM which allows you to select a DSK on the HxC.
Quote from: TFM/FS on 01:55, 02 February 13
Hi, you can use a software solution. For the CPC there is a ROM which allows you to select a DSK on the HxC.
Thanks for the explanation that actually sounds like a better option than having an LCD screen
So much I don't know!
The LCD screen is actually functional enough and it also has the advantage of looking nice and geeky. But the software option is so much easier to use!
I like the option to enable the CPC itself to control everything. Why?
For example a game can switch to another DSK (new levels f.e.) by itself, so it must not bug the user to "Change fecking irish disc please"[nb]Sentence taken from the game 'Feckin St. Patricks day in New Orleans'[/nb].
Personally I prefer the LCD solution. I don't know of any software that can change the DSK on the HxC automatically like TFM mentions. Is there any? Even if it did exist, that would work independent of whether you used the LCD or not.
Bryce.
Check out the HxC ROM for the CPC, you should have it in your Megaflash.
I have it already, but I wasn't aware that it automatically swaps disks for you!
Bryce
No, that's not what it does. But as you can use it to do that by hand, the same routines can be used in games, right?
Yes, you could, but no-one has done it yet as far as I know. But it would also be possible even if you normally used the LCD.
Bryce.
My point was to enable software to switch the DSK file that is accessed, which can be done by the HxC driver software on the CPC side.
Hi Bryce
Can you pls confirm that R29, 10K is needed as it's not listed in the wiki article.
According to the schems this is the asic option setting to enable the disc controller.
Cheers Buddy, superb thread.
TC ;)
Oooo, probably a mistake on the Wiki article. I'll check it out and edit the article :(
Edit: I just checked my notes and photos of the conversion. The reason I didn't mention R29 was because it was already present on the 464+ board for some reason. If your board doesn't have this resistor installed you'll need to add it. Can you check your board and let me know if it is there already?
Bryce.
Hi,
I've been asked for the pinout details for the Laptop Floppy drive which I modded above (and which never got installed anyway). The 26pin header on the laptop floppy drives are according to a standard, so the following file should be correct for most old shuggart laptop floppy drives. The two green columns in the sheet are all you need, the other rows are just for reference. Pins 6,7,9,11 and 13 on the laptop floppy connector aren't used by the CPC. Also, don't forget to connect pins 1,3 and 5 of the laptop connector to the CPCs 5V rail.
Bryce.
Hi all,
I've just finished playing loads of games on extensively testing Craigs 464+ which I've also converted to 6128+, however, Craig wanted a slightly different setup for the drives, so I thought I should document this version too. Craig wanted both drives to be external with an ABBA switch, so here's how it's done:
[attach=2]
The DS0 signal can be found on pin 4 of the 26way header. If you just want both drives external without an ABBA switch, then all you need to do is connect this directly to pin 9 (5th from the left) of the Centronics socket. In this case Craig wanted an ABBA switch, so I have cut pin 11 (DS1) so that I can swap the signals with a small switch. So DS0 source is pin 4 of the header, DS1 source is the PCB side of the cut pin 11. DS0 output is pin 9 of the Centronics socket and DS1 output is the socket side of the cut pin 11. The external cable is the standard Plus cable for 3.5in disks (as on the Wiki), but with two 34way headers and no twist (as found on PC floppy cables).
Bryce.
Ooh, really excited now. I have 2 3.5 inch drives waiting. Oh and an hxc and an fd1. This will become my main Cpc. Oh how such a short time my 6128plus with tape mod was king. Oh well 2 machines of same spec in different cases. Before packing back into the unblemished case I might even put a reset button in too.
Craig
Well it will need to be slightly blemished. You need to cut the hole for the floppy port like the 6128+ has and a small hole for the ABBA switch.
Bryce.
Quote from: Bryce on 08:24, 20 October 14
Well it will need to be slightly blemished. You need to cut the hole for the floppy port like the 6128+ has and a small hole for the ABBA switch.
Bryce.
oh indeed. But it's not going to go yellow by having 3 small holes cut in it. Reset & abba switches and drive port.
No. If it hasn't gone yellow already, then it probably never will.
Bryce.
Hi Bryce, what is the width of the tape unit cover on the 464+? Is it wide enough to fit a MotherX4 board in that spot with the cards sticking out the top?
Quote from: zhulien on 00:00, 28 January 17
Hi Bryce, what is the width of the tape unit cover on the 464+? Is it wide enough to fit a MotherX4 board in that spot with the cards sticking out the top?
Hi, the tape lid is 11.8 cm long and 8 cm wide.
The MX4 is 8.4 cm wide (due to the power connector), but if you remove the tape unit completely, you may be able to fit the MX4.
To me that sounds like a good idea, worth picking up a 464+ to mod... Might even be able to convert the buttons putting a sensor below them (unless they are physically part of the tape unit to be removed), eg: play button to be ROM enable/disable, another button for reset, then 4 more spare buttons for future use :D
The buttons are part of the tape unit, yes... you can have a look at them in this picture :)
(http://www.cpcwiki.eu/forum/index.php?action=dlattach;topic=12058.0;attach=19464;image)
looks like they could be taken off with some type of pushbutton below - so they would become extenders for cosmetic purposes - like the Amiga 4000 PSU button, but shorter. Lots of space inside if you remove that tape unit. Did you add a disc drive plug to that?
It could work, but I think it will be very difficult to mount them at exactly the right position and lined up unless you use at least some of the original tapedeck frame.
Bryce.
Great info in this thread and looking at doing this mod. Not sure if anyone has the hard to find chips available for sale. I found some on ebay/aliexpress
https://www.ebay.com.au/itm/113748919765 (https://www.ebay.com.au/itm/113748919765)
Can confirm the ebay NEC chips work in the DDI1 boards I built a few months ago
https://www.aliexpress.com/item/1005001968866175.html (https://www.aliexpress.com/item/1005001968866175.html)
@Bryce I'm running through the upgrades now. The list of parts is missing C99 (47uF 16V) from the Amstrad action parts list
https://www.cpcwiki.eu/index.php/464Plus_Conversion (https://www.cpcwiki.eu/index.php/464Plus_Conversion)
Quote from: darkhalf on 09:43, 21 July 23@Bryce I'm running through the upgrades now. The list of parts is missing C99 (47uF 16V) from the Amstrad action parts list
https://www.cpcwiki.eu/index.php/464Plus_Conversion (https://www.cpcwiki.eu/index.php/464Plus_Conversion)
Yes, C99 was added by Amstrad Action, but I'm not sure why. It doesn't exist on a real 6128+ and the system works fine without it. Maybe just being extremely over cautious?
Bryce.
Maybe it was just on the 6128+ which the original project was based from (but not others). Could only think it was extra frequency filtering in addition to the 0.1uf decoupling caps