Hurrah! My CPC 6128 has arrived.

[Charlie]

I'm most pleased to say my 'new' CPC 6128 arrived today. Ah, the flood of happy memories, even if it  was a '464 I had back in the day...

Now let the modding commence.

This has got to be the most dirty computer I've ever seen - the keys look like they came right out of the head of a 500-a-day nicotine junky...
...inside I've not seen that much fluff 'n guck since the incident involving a chicken, a belly dancer, and half a pound of industrial grade lard. Still, I got that ruby in the end*

#1) Thorough cleaning, I think, is the first port of call.
Recipe:
-Take it all apart
-A good few quirts of Oxy.
-A blob of washing up liquid
-A big blob of PVC window cleaner.
Attack all plastic items with a tooth-brush using the above mixture and leave for a bit.
Meanwhile...
-Lemon juice
-Acetone
-A hint of washing up liquid
Gently toothbrush the motherboard with that, having unplugged / unsocketed anything that can be removed.
...and shove all items in the dishwasher (no more than 40deg, no cleaner, wires and FDD not a good idea).
24 hours drying and I'll put it all back together. That should give me time to make up a RGB-SCART lead and some kind of PSU.

Hmm, I usually let old computers keep their patina of age but in this case I think those keys are going to need the Retr0Brite treatment.

I'm likely to have lots of questions once I start in earnest, I'm afraid.


*possibly not true.

[arnoldemu]

I'm most pleased to say my 'new' CPC 6128 arrived today. Ah, the flood of happy memories, even if it  was a '464 I had back in the day...

excellent

I'm likely to have lots of questions once I start in earnest, I'm afraid.

no problem.

[redbox]

Glad to hear you have a real 6128, great news.  Give it a month and you'll wish you had a 6128 Plus 

Gently toothbrush the motherboard with that, having unplugged / unsocketed anything that can be removed.

Does this just clean it or does it help with anything else?

...and shove all items in the dishwasher (no more than 40deg, no cleaner, wires and FDD not a good idea).

I take it you're not including the motherboard etc here...?!

[steve]

I have read of people who say they have put printed circuit boards in the dishwasher, but I do not have the courage to try it myself.

[Charlie]

Thanks chaps.


Believe it or not the dishwasher is your retro computer's friend! Even the motherboard.
Having had a peek I suspect it's less of an issue with the CPC (few socketed chips) but apart from getting a sparkly result it's a good way of getting cr*p out of the sockets that seems to be a primary cause of instability. Again the CPC doesn't have a battery but with the right ingredients it can be a good way of getting exploded battery guk off the PCB. (really bad)
The tricks are:
-not to be too brutal with the initial tooth-brushing (if it's the PCB you're doing)
-make sure everything that will unplug is removed first
-not to have the dishwasher on too hot (<60C)
-for God's sake don't put in a dish-washer tablet!
-be utterly confident the system is 100% dry before running it again

For the plastic it gets things lovely 'n clean but won't change any yellowing - Retr0Brite for that.
Post dish-washer plastic also tends to take paint well for custom jobs. (I don't do much of that these days)
If you're not spraying and feeing a bit 'anal' Vaseline frugally applied with a baby wipe is good for bringing the washed plastic back to something like it's new appearance. (after tooth-paste also good for getting scratches out of TFT's)

P.S.
Should I mention that the oven also has it's uses (if you're desperate)?

[Charlie]

Right, brace yourselves...

First batch of questions:
-Drives-
FDD:
It seems a HxC would a good replacement for the 3" drive regardless of how the original is working.
Also a 3.5" FDD + ABBA switch could be useful...
...I'm thinking of mounting both in the space usually taken up by the original FDD along the lines of Pentagon's mod + a slim-line 3.5" IDE FDD. Can anyone think of an obvious reason why not? Are there any known 'bad' 3.5" drives for CPC's? (I suspect if any will be troublesome slim-line ones may be)
HDD:
What's the simplest way of getting a HDD (internally) in to a CPC? Previous experience with other retro systems suggests IDE->CF adaptor + some kind of IDE interface.
I see Yarek has done a HDD interface but what's the support situation if one is using something other than FutureOS..? From what I've read it's otherwise a floppy image store rather than a 'true' HDD.
-ROMs-
Bryce has done a very nice ROM board - sorted..? I wonder if I could adapt it to fit upside-down under the mobo. I could then cut a trap-door under the CPC for access to the EPROM...
-RAM-
Looks like Yarek (again) to the rescue with his 4Mb expansion. Having had a nose on Yarek's site I see he's kindly published the schematics etc... Are there details for the required motherboard mods, or have I missed them?
I see Yarek mentions doing the work for an amazingly good price - still available?
-Video-
For now I'll make up an RGB-SCART cable but for me it's not ideal as only the family telly has a SCART connection.
My other retro systems have either been modded to output 'proper' VGA or S-Video. I guess VGA from a CPC is too much trouble (for now) but can one get some kind of S-Video out of a CPC? My BBC Master has S-Video using the comp-video and grabbing colour from the CRTC - the same chip as the CPC??
-Bits 'n bobs-
Am I right in thinking the SYMBiFACE II is no-longer available for sale and construction plans not available?
Happy 8Bit Mod for the printer port..? Is the patch for this ROMable rather than needing to load?

How's compatibility between these various additions? Are there (better?) alternates? What else?

Mmm, then time look in to a few additions of my own. (I'm not so good at leaving my systems in peace)

[Charlie]

Not just a double post, a triple post:


RGB-SCART issue:
I wired up a cable as per the following diagram:

from the Wiki of course...


But all I'm getting is a B+W image, and not an amazingly clear one at that.
-Checked & double checked the wiring
-Tried a range of (optional) Caps from 10uF to 220uF - 10uF gives the most stable image
(no Cap gives white over green ghosted text with a black background)
(with Cap gives white text on back background)
-The TV (Toshiba TFT) is fine with my Beeb attached using RGB-SCART so I guess it's forgiving enough


Any tips as to how I can fix this?
In case it matters the only 5v PSU I had to hand is rated @ 1A - how much does a CPC need?
It makes no odds about having a 12v PSU apart from the lack of a FDD
Hmm, time to see if those Y & C signals can be found anywhere...


Thank you!

[Gryzor]

Glad to hear the news, mate! And not a day too soon!

Concerning cleaning, that's what I always do when I get a new machine - take it apart, clean it thoroughly, then take some pics (get the hint??).

However, it looks like you're using lots of harsh methods - almost all of the ingredients you mentioned cause degradation of your materials...

Washing machine: people, washing machine detergents are VERY harsh, much worse than the kitchen sink ones! So much so that, actually, you shouldn't take all the dirt off your dishes, because the detergent is designed to attack it and if the dishes are clean it will attack the surface material. You *can* put a motherboard in the washing machine, but only for the benefit of warm water under pressure, *without* any detergents.

Just my €0.02

[redbox]

RGB-SCART issue:

I am no expert on this, but it has been discussed before so maybe you need the 1.5v power supply (battery) for it or the lead is too long?

[arnoldemu]

Right, brace yourselves...

First batch of questions:
-Drives-
FDD:
It seems a HxC would a good replacement for the 3" drive regardless of how the original is working.
Also a 3.5" FDD + ABBA switch could be useful...
...I'm thinking of mounting both in the space usually taken up by the original FDD along the lines of Pentagon's mod + a slim-line 3.5" IDE FDD. Can anyone think of an obvious reason why not? Are there any known 'bad' 3.5" drives for CPC's? (I suspect if any will be troublesome slim-line ones may be)

The normal problem is the ready signal. But there is lots of info on amiga websites about how to modify pc drives. In addition, some pc drives are easy to modify, just move the surface mount resistor from DC to RDY.
I've done a few and it's worked fine. CPC doesn't need DC signal.
So it's even simpler than mods for amiga.

HDD:
What's the simplest way of getting a HDD (internally) in to a CPC? Previous experience with other retro systems suggests IDE->CF adaptor + some kind of IDE interface.
I see Yarek has done a HDD interface but what's the support situation if one is using something other than FutureOS..? From what I've read it's otherwise a floppy image store rather than a 'true' HDD.

I think it'll be a bit of a squeeze, but possible. Power will be a problem because the cpc normal power supply doesn't have enough to give other things. So you'll need to power this external.

I use an old pc power supply to power my cpcs. I made up some cables to connect to the IDE power connectors, and split this into the 5v power for the computer and 12v power for the cpc's 3" drive,

In terms of software support: FutureOS,symbiface or BonnyDOS at this time. BonnyDOS requires it's own disc format (not fat), but you can use it from AMSDOS. There was another rom in development that would read hd, but it's not been finished.

-ROMs-
Bryce has done a very nice ROM board - sorted..? I wonder if I could adapt it to fit upside-down under the mobo. I could then cut a trap-door under the CPC for access to the EPROM...

Bryce could answer that. He's very good with that kind of thing, and reading from your existing posts, so are you.

  -RAM-
Looks like Yarek (again) to the rescue with his 4Mb expansion. Having had a nose on Yarek's site I see he's kindly published the schematics etc... Are there details for the required motherboard mods, or have I missed them?
I see Yarek mentions doing the work for an amazingly good price - still available?

In terms of ram, not a lot will use more than 128k of ram.
There is only a very few select software that detects and will run with more ram, but perhaps in the future there may be more.
Although most software supports 64k, really you need at least 128k of dk'tronics 100% compatible ram.
Other ram expansions, e.g. vortex, are not easy to build and not so well supported.

    -Video-
For now I'll make up an RGB-SCART cable but for me it's not ideal as only the family telly has a SCART connection.
My other retro systems have either been modded to output 'proper' VGA or S-Video. I guess VGA from a CPC is too much trouble (for now) but can one get some kind of S-Video out of a CPC? My BBC Master has S-Video using the comp-video and grabbing colour from the CRTC - the same chip as the CPC??

Well the BBC has the same family of 6845 CRTC chip, but also has it's ULA which generates the signals.
The CPC has the 6845 and it's "Gate-Array".
CPC outputs composite sync, and analogue r,g,b. You may need extras to make s-video but really I don't know enough about this.
SCART is probably the easiest, myself I use a cpc monitor.

     
-Bits 'n bobs-
Am I right in thinking the SYMBiFACE II is no-longer available for sale and construction plans not available?

I believe so, anyway it's got a FPGA or similar on it anyways.
You'd probably get similar mileage with a ram expansion,  Bryce's mouse expansion, his flash romboard, and Yarek's or similars IDE.

        Happy 8Bit Mod for the printer port..? Is the patch for this ROMable rather than needing to load?

Well, to support it in rom, you would either need to have another rom and have the firmware patched (which is possible), or have a modified firmware. Both are possible.. if you need either, I can make the code up fairly quickly.

How's compatibility between these various additions? Are there (better?) alternates? What else?

Mmm, then time look in to a few additions of my own. (I'm not so good at leaving my systems in peace)

Well, my opinion is that you need at least 128k disc based system. You need to be able to connect it up to the pcs sound card (so you can transfer cassette software), but also you need cpcdiskxp utility so that you can write 3.5" floppies from your pc to be used on the cpc.

Now, this means you need an internal 3.5" drive on your PC and a older motherboard - I think you mentioned this before?

In addition a side switch is a must.

As you're planning an internal 3.5" drive, you don't need the ABBA drive switch, but perhaps it could come in useful in the future (this switches the drive select lines).

As well as that, I would also go for a reset switch.

If you can do it, either use a romboard, or put in a version of parados onboard within your 6128. Parados is one of the best alternative dos that can access 800k discs.

I think with all these in place your in a great position to enjoy all the cpc software.

Another thing to consider is making up a digiblaster, more software supports this, and so you could enjoy sampled sound created this way.

[Charlie]

Thanks very much for all the most helpful replies, I appreciate it and also now have some firmer plans.

Hmm, digiblaster - looks interesting.

I can see RGB-SCART could be a problem with the TV I have. I wonder... an RGB-CompVideo / S-Video board - Would this be something others may be interested in?
Having said that my study is awash with 1/2 finished projects so such a thing may be a while coming.

Happy Christmas all!

P.S.
@Gryzor - don't worry. I wouldn't recommend going bananas with detergents either (definitely not dishwasher powder/tablets). I've not dissolved anything yet.

P.P.S.
Cleaned CPC6128

Sorry, no before photo

[Gryzor]

Well, it *is* a beauty, but I'm afraid to ask about the Vaseline!

Wow, this looks perfect... Can I send you mine?

[Charlie]

Well, it *is* a beauty, but I'm afraid to ask about the Vaseline!

Wow, this looks perfect... Can I send you mine?

Blush:
Praise indeed - I have to admit it looks better in the photo than the flesh.
(Very sparing dabs of Vaseline well rubbed in to the plastic can work wonders)

Well, Christmas Eve and time to do the Santa thing for my daughter so I'd better give up on the RGB-SCART connection...
...no matter what I try the best output I can get is by using a combination of the above schematic with a 220uF Cap + a 1.5v battery across pins 16 & 18: I get very 'rough' output that at least now has a blue background though the text that ought to be yellow is brown with dark green ghosting.
The other schematics on the Wiki give no output at all!

Any ideas / alternate schematics?
(For some reason I've never been able to get my head round SCART so have trouble doping this out for myself)
Maybe an RGB-Comp / S-Video board will have to go top of the list of project priorities...
...Hmm, unless the monitor for my '464 is still in my parents garage.

[Bryce]

Hi Charlie,
        looks like you plan to stuff an awful lot into the 6128. There's not much room, so you better plan it well. I have a wireless mouse adapter installed in my 6128 and that took almost all the area that was available: http://www.cpcwiki.eu/index.php/PS2Mouse#Wireless_Internal_Version

The MegaROM might also fit in this space, but I haven't tried it. Connecting it to the inside of the Expansion port shouldn't be an issue, but you'll have to add a switch to disable it.

The SCART issue (BW picture) is because your TV is reading the composite inputs of the SCART socket. You'll either need to switch to RGB manually or if the capacitor isn't working, you may need to add a 1.5V battery there instead.

If you want your 6128 to have a composite output (which can be used on an S-Video input with an adapter) then you need to either get an MP2 and convert it or make your own RGB to composite circuit. Schematics here:  http://www.cpcwiki.eu/index.php/LCD_And_Plasma_TV_Solution

Regarding the dishwasher usage, even if you don't put the Tab / Detergent in there's still dishwasher salt which you can't easily remove and this can be really corrosive on bare metal. Generally I wouldn't recommend people to put any PCBs in a dishwasher.

Bryce.

[Charlie]

Hi Bryce,
Yes, much to try and stuff in to my CPC (eventually) - it's most of the fun for me.
Thanks for the info. Nooo, no salt in the dishwasher - just water. I'm not recommending everyone should wash their motherboard. A good going over with a soft brush should be fine, but where there's a lot of guk or a motherboard to rescue from a poorly battery...

Mmm, SCART's annoying me now. Here's a little thing I did last night and this morning - should work for any system with RGB-out...



...the image is 200% the actual size - just a PCB layout + parts list at the mo'. It may be a while before I get round to testing it. If anyone's interested in beating me to a physical prototype I can provide a PDF version for printing + what the parts actually are.

I hope everyone's having a very happy Christmas!

P.S.
Why do I get extraneous sizing / layout stuff in my posts when I try to edit them - what am I doing wrong?

[Bryce]

Hi Charlie,
      hey, you're a hardware person too That's cool, we seem to be a minority in the CPC scene. The RGB to Comp. in the MP2 is based on the MC1377, which I had a couple of, so I based my design on it too. It supports PAL and NTSC too, but the AD724 has supposedly a better picture quality, but I couldn't find a supplier here (Germany) so I've never built a converter using it.

If you intend building any of the stuff I've put online then let me know, I can send you the original schematics files (usually Eagle or OrCAD), then you can define the footprint and layout for yourself, so that you can pack the intended 15 PCBs into your 6128 or build a single PCB with all the interfaces on one board?

How do you produce your PCBs? UV / photo-boards / Acid bath etc? Or do you have a CNC setup?

Bryce.

[Charlie]

Thank you for calling me a hardware person.

I can make a PCB and rehash other's ideas but I'm not remotely in your league. I don't have any AD724's as yet, so I hope sourcing isn't going to be too tricky.

I've got Eagle and ExpressPCB on my PC but (maybe weirdly) I usually use Inkscape (Windows) or RiscPCB (RiscOS) - maybe it's because I haven't done anything complex enough to require proper tools but I like simple as I find it doesn't get in the way of the process.

Thank you very much for offering up your original schematics, that most kind.

I have to admit my 'technique' is pretty basic - Press 'n Peel + Ferric Chloride.

This kind of thing - not my design:

Seems the limit of the technique in my hands, so I should probably try something new.

[Bryce]

I usually use Eagle, but through my company I have access to OrCAD, so I use it sometimes too. But using inkscape, etc. isn't all that unusual, I do the same for single-sided designs, because I find Auto-Route routines are crap at doing anything less than 2 layers.

That's an impressive result for press and peel. I print to a clear foil (overhead projector type sheets for laser printer) and use UV on Photo-sensitive PCBs, much easier to keep things aligned on double-sided layouts. I also use Sodium Persulfate instead of Ferric Chloride. For a start it's not murky-yellow, it's clear to light blue, so you can monitor the process easier and it also doesn't smell as nasty as Ferric Chloride. You should give it a go.

Building my own CNC machine has been on my to-do list for several years, but I never seem to get around to it There are loads of plans for DIY CNC machines on the internet.

Bryce.

[Charlie]

Sodium Persulfate... I've been meaning to try that out for a while - waiting for the bag of Ferric Chloride to run out.
A chap I kind-of know doesn't bathe his PCB's - a pair of rubber gloves + F.C. + sponge and sort of wash the copper-clad by hand...
...he swears it's easy and really reduces the amount of consumables - it doesn't seem to work for me so bathing in something clear would be useful.


I've been meaning to try the UV technique as P 'n P with two sided PCB's is REALLY HARD...
...I wonder if my EPROM eraser would do the job..? (Pretty well all the PCB's I make are small as everything I've made so far has gone inside a retro computer)

[MacDeath]

Instead of trying to put all those things into the CPC (it won't fit easyly) try instead to get an external unit...

The ideal could be a shuttle PC casing (only the casing)...And a lot of cables of course.

but I don't know if those are easy to find and cheap.

Thanks for the various tips to get a shiny CPC...
I should read them with more attention.

[Charlie]

Hello all,
I hope everyone's had a happy Christmas and New Year.

Ahh, of course you're right. If I had any sense using an external box is what I should do...
...but then I have very little sense - it appeals to my warped mind to see just how much I can cram in to an original case.
(One of my more ridiculous experiments has been to build a PC in to an Oric Atmos - not finished yet)


Back to Amstrads:
Just printed the latest version of my RGB->SVideo (composite) board - waiting on the AD724's to come from Hong Kong (good ol' fleaBay) and I'll solder it up.

Um, well. I'll try to solder it up - in the interests of making it as small as possible the above PCB has turned out about the width of my thumb and 2/3 the length!
Here's hoping it actually works, I've no idea how to debug it if it doesn't.

[OCT]

Having seen the inputs of some TV sets and AV receivers in the post-Xmas re-wiring of a few friends' places lately, I've come to realize most recent gear (besides accepting Composite) expects Component rather than RGB or S-Video (the connectors for which have disappeared on many devices) as the "best" analog input to upconvert/scale to HDMI internally (a favorite for the single run of wire so much rather than its dreaded DRM).
Any proposals/experiences on an easy way (i.e. max. quality @ min. circuitry ) to turn the CPC's RGB into Y + PB/CB + PR/CR ?

[redbox]

I am going to get a new 6128 Plus soon that I want to mod.  However, I   want to make sure that it's as clean as can be before I start and this   includes the PCB.
 

-Lemon juice
-Acetone
-A hint of washing up liquid
Gently toothbrush the motherboard with that, having unplugged / unsocketed anything that can be removed.

Is the above a good idea and how would I go about it?  What about the residue (just let it dry)?  And what quantities should I be using?  And is it worth it (i.e. does it generally make stability better etc)...?

[Charlie]

@OCT:
A good question - frankly I don't know. I'm pretty well starting from ground zero with my 'new' 6128 and don't know what's there to 'bend'.
I know you can get S-video (for example) out of a BBC B or Master and am looking in to doing the same trick with the Arc' - but then these are machines that didn't come with their own monitor so of necessity came with extra hardware.

@rebox:
I think it's fair to say that I'm and old butcher and can take an almost perverse pleasure in using what's to hand rather than doing it 'properly'. With that in mind here's my thoughts on what can often be a contentious subject:

If in doubt do the minimum required to get where you want to be, that way there's less chance of doing harm.

If it needs cleaning at all:
For the case baby-wipes will do 9 times out of 10.
For the PCB a very, very soft brush is nearly always the most you need to do.

-------------------------------------------------------------------------------------------------------------------------------

If stuff needs properly cleaning:
You won't go far wrong using something you'd feel safe using in the bath, or something designed for purpose if you must!
ALWAYS rinse thoroughly after cleaning.
ALWAYS make sure everything is 100% dry BEFORE you power it up again.
NEVER use any acid/caustic/abrasive materials ANYWHERE on your computer.*
NEVER use any kind of solvent on plastic cases.*

Unhappy or really crusty computers may need The Treatment:
Plastic cleaned with the aid of a tooth-brush + your favoured detergent mixture (dilute) and then (optionally) shoved in the dishwasher...
...LOW temp, NO dishwasher powder, NO salt.
PCB cleaned with either proper cleaner or Lemon juice*+ Acetone* + A hint of washing up liquid (dilute) and then (optionally) shoved in the dishwasher...
...LOW temp, NO dishwasher powder, NO salt. Don't forget to remove ALL components you can, and extract ALL socketed chips first - IMO the primary cause of instability in old computers is dirty sockets and poorly seated chips.

*Hey, isn't Lemon juice an acid and isn't Acetone a solvent..?
Yes, and yes...
...The PCB doesn't mind these, and Lemon is good for general 'guk' and leaky battery goo - not a problem for CPC's, obviously.

There's plenty more that can be done if you want to go for the 'factory fresh' look though I generally don't go that far - http://retr0bright.wikispaces.com/ is worth a look.

I hope that helps a bit.

[redbox]

With that in mind here's my thoughts on what can often be a contentious subject:

That's really helpful Charlie, thank you for all the pointers.