Hi All,
I've been reverse engineering the Rombo ROMboard and have a full schematic and some PCBs made, but it doesn't work, on boot the CPC either remains Black screen or has weird lines going up it
I'd really appreciate someone with more knowledge just to give the schematic the once over and seeing if they can see anything obvious.
Thanks in advance :-)
Rob
have you checked the reversed engineered board schematic with the original board to see if each connection is the same?
If they are the same then are the components used the same as the original even for the tolerances?
rpalmer
The schematics match my notes I had on the Rombo schemtic. (As far as they go, my notes are incomplete)
What debugging tools do you have (multimeter, scope, logic analyzer?).
Does it give the black screen with no roms and all the switches turned off or only when roms are inserted/enabled?
Have you checked the power supply to each chip.
Can you post some pictures, someone might spot something obvious.
I don't see anything obviously wrong in the schematic. The first thing to do would be to check that all ICs are getting 5V. After that I'd monitor pin 43 of the expansion port to see if the device is permanently disabling the internal ROM.
Bryce.
I have re-assessed the schematic and see a flaw.
If you enable the rom board with ROM 0 then the internal ROM (both upper/lower) is disabled with only a 16K ROM in the ROM board.
Not such a good design on start up when ROM 0 needs to be 32K.
You need to have for ROM 0 an Upper / Lower 16K select on the 32K ROM based on A15 (if high then Upper ROM else lower ROM). The is achieved by simply connecting A15 to ROM A14.
rpalmer
Quote from: rpalmer on 11:14, 05 March 18
I have re-assessed the schematic and see a flaw.
If you enable the rom board with ROM 0 then the internal ROM (both upper/lower) is disabled with only a 16K ROM in the ROM board.
Not such a good design on start up when ROM 0 needs to be 32K.
You need to have for ROM 0 an Upper / Lower 16K select on the 32K ROM based on A15 (if high then Upper ROM else lower ROM). The is achieved by simply connecting A15 to ROM A14.
rpalmer
The roms are only enabled if A15 is high. A15 is fed into pin 1 of the 74hc00. Follow it back from pin3 of the expansion connector.
I've solved the black screen problem and its a doozy. If you have a look at the schematic at the link between r9 and d1 there should be a little dot where it joins. There wasn't, so even though it looks connected it isn't. Connecting it fixes the black screen issue and allows the CPC to boot correctly, however it still doesn't work, I dont get any ROM sign-on.
I'll check the suggestions that could now be relevant - more comments welcome!
Cheers
Rob
Quote from: IanS on 16:19, 05 March 18
The roms are only enabled if A15 is high. A15 is fed into pin 1 of the 74hc00. Follow it back from pin3 of the expansion connector.
The schematic will force ROMEN (Pin 42) to be High when no ROM is selected and so the internal ROM is no longer selectable as there is now a clash of voltages. The clash comes from the Gate Array output of ROMEN and the ROM board setting of ROMEN (a potentially bad situation for the gate array). This will occur when the upper ROM 0 calls for a routine outside of the upper ROM and is not a problem if ROM 0 is 32k and both are handled via ROMDIS line only.
All external ROM boards need to only use Pin 43 (ROMDIS) to stop the internal ROM output from being seen. The gate array is not connected to the ROMDIS line so all should be okay if you set it high permanently when the ROM board is connected and the external 32K ROM 0 is inserted.
rpalmer
Quote from: rpalmer on 22:30, 05 March 18
The schematic will force ROMEN (Pin 42) to be High when no ROM is selected and so the internal ROM is no longer selectable as there is now a clash of voltages. The clash comes from the Gate Array output of ROMEN and the ROM board setting of ROMEN (a potentially bad situation for the gate array). This will occur when the upper ROM 0 calls for a routine outside of the upper ROM and is not a problem if ROM 0 is 32k and both are handled via ROMDIS line only.
All external ROM boards need to only use Pin 43 (ROMDIS) to stop the internal ROM output from being seen. The gate array is not connected to the ROMDIS line so all should be okay if you set it high permanently when the ROM board is connected and the external 32K ROM 0 is inserted.
rpalmer
ROMEN is an output from the CPC. It's only fed into the input of the 74hc27 and the CE of the roms, but the OE of the roms will only be selected when the appropriate rom is selected (and A15 is high).
Are we looking at the same schematic? Which output do you think is driving ROMEN?
Nobody is suggesting using 32K external roms (or at least I'm not), the Rombo rombox was never intended to support that use case.
sorry about that IanS, I mis-read the schematic.
Okay, I think I know what this is.
It seems I have fallen victim to something called "the curse of the invisible power pins"
[/size]
[/size]Some Logic chips have "invisible" power pins meaning they don't show up on the schematic and you cant attach them to your nets, Altium is supposed to just do this automatically.
[/size]What Altium has done in this case is created a new VCC net for the 27 and 30 ICs and just joined them together without connecting them to the actual power nets.
[/size]Now I can be pretty sure my Reverse Engineer is sound I can start redoing the board, paying particular attention to the Power pics of the chips with Hidden Pins.
[/size]IanS, as ever, thank you for your help, Gerald too, I'm going to go and get this redone.
[/size]Cheers
[/size]Rob
If I may re-quote myself:
Quote from: Bryce on 08:42, 05 March 18
The first thing to do would be to check that all ICs are getting 5V.
Bryce.
:)
Bryce.
P.s. Doesn't Altium have an Invoke command to make the hidden pins visible?
Bryce,
I can barely use this damn program normally, let alone know about extra commands like that :-)
Regards
Rob
Quote from: The Equalizor on 15:24, 06 March 18
Bryce,
I can barely use this damn program normally, let alone know about extra commands like that :-)
Regards
Rob
http://www.altium.com/documentation/18.0/display/ADES/Sch_Cmd-ToggleHiddenPins((ToggleHiddenPins))_AD
For the next time... :)
Bryce.
Oooh yeah that works great!
Cheers :-)
Rob
Quote from: The Equalizor on 12:05, 06 March 18
What Altium has done in this case is created a new VCC net for the 27 and 30 ICs and just joined them together without connecting them to the actual power nets.
So if you add some wire links does it all work ok now? Any pictures?, please.
Yes, pictures please!
I always wanted to build a classic old-style EPROM-based ROM board for my CPC myself. I have plenty of EPROMS. Flash-based ROM boards are of course the current standard, but hey, EPROMS are cool. 8)
Better use the Dobbertin Card then (7 * 32 KB, 14 logic ROMs). It has superior technology. Ok, maybe some custom chips too, but the probably all have.
Also Bryce made a very decent MegaROM card.
Quote from: GUNHED on 23:04, 07 March 18
Better use the Dobbertin Card then (7 * 32 KB, 14 logic ROMs). It has superior technology. Ok, maybe some custom chips too, but the probably all have.
Also Bryce made a very decent MegaROM card.
I wouldn't consider my MegaROM to be a classic ROMBoard because it puts all ROMs on one EPROM so these original ROMs can't be used on it. If you're looking to build your own real classic ROMBoard I'd recommend something like the ACU ROMBoard: http://www.cpcwiki.eu/index.php/ACU_Romboard_(DIY) Full instructions and relatively easy to build. If there's interest, I could get a batch of PCBs made up for those who want to try some soldering.
The Dobbertin 224 didn't use any custom chips, the just made good use of the 74LS154 multiplexer. It's a nice board, but the jumper settings are way too complicated.
Bryce.
Quote from: Bryce on 08:27, 08 March 18
If there's interest, I could get a batch of PCBs made up for those who want to try some soldering.
That'll be awesome, count me in for that one, too :D :)
Quote from: Bryce on 08:27, 08 March 18
I wouldn't consider my MegaROM to be a classic ROMBoard because it puts all ROMs on one EPROM so these original ROMs can't be used on it. If you're looking to build your own real classic ROMBoard I'd recommend something like the ACU ROMBoard: http://www.cpcwiki.eu/index.php/ACU_Romboard_(DIY (http://www.cpcwiki.eu/index.php/ACU_Romboard_(DIY)) Full instructions and relatively easy to build. If there's interest, I could get a batch of PCBs made up for those who want to try some soldering.
If you make some PCB's, make anything but the ACU board, it's a terrible design. It at least needs to decode the full rom number - http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/acu-romboard-remix-not-working!-help-required/ . But there are other issues.
Add a couple more chips and do a Rombo clone. With a pre-made PCB, the low chip count simplicity of the ACU design is largely irrelevant.
Ok, tell me which device to produce (with modifications if required) and I'll have some PCBs made up. If required I can make up kits with the parts too.
Bryce.
@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225)
The link Goes to a blank Page ?
http://www.cpcwiki.eu/index.php/ACU_Romboard_(DIY (http://www.cpcwiki.eu/index.php/ACU_Romboard_(DIY)
Thanks Ray
I am always ready for some soldering :D
Quote from: Audronic on 23:08, 08 March 18
@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225)
The link Goes to a blank Page ?
http://www.cpcwiki.eu/index.php/ACU_Romboard_(DIY (http://www.cpcwiki.eu/index.php/ACU_Romboard_(DIY))
Thanks Ray
Add the closed bracket at the end!
Quote from: tjohnson on 00:34, 09 March 18
Add the closed bracket at the end!
Oops
Yes it now works.
Thanks Ray
Quote from: Bryce on 20:49, 08 March 18
Ok, tell me which device to produce (with modifications if required) and I'll have some PCBs made up. If required I can make up kits with the parts too.
Bryce.
I think the Rombo design is pretty good. Which is where the thread started. As far as I know the circuit in the first post is good.
Ok, as soon as the @The Equalizor (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2279) has confirmed the design I'll make up a layout.
Bryce.
I'm actually having some PCBs made, should be here in a week or so. There will be spares if anyone wants to buy one and kits/built available too if that sparks anyone's interest.Obviously I need to make sure it works.
Rob
Cool. That saves me from having to do it :)
Bryce.
Although lets be honest, you're a freakin' CPC genius so your take on it would probably be 100 times better than mine. Do you use Altium?
Rob
I've used Altium in the past at work, but my main experience is with OrCAD and some (hobby) Eagle.
My take on it probably wouldn't be much different to yours. I like to get the PCB size down to an absolute minimum, so that might be different, and if I was building them myself I'd probably use SMD for the logic and passives and put them underneath, but as it's for kit purposes, I'd stick with all thru-hole this time.
The problem with classic ROMBoards (as you've most likely just found out) is that there's an aweful lot of soldering to be done! :D
Is yours done to be "M4 friendly" ? That's something I would also have done.
Bryce.
I strongly support the whole "through hole" notion :) I much prefer to solder these than the SMD :D
I would definitely be interested in a fully assembled classic ROM board or Rombo Rombox clone if someone was going to make one.
I would be interested in a board and happy for just the raw board which is the difficult bit for me and to buy the components solder myself but not smd! If you were able to include an idc connector header and make ribbon cables available like talrek does with the mf2 clone that would be welcomed.
Sent from my E5823 using Tapatalk
Ah now you see I'm the opposite. I hate thru-hole and much prefer to work on SMD. PCBway has a limit on "cheap" PCBs of 100mmx100mm so I'm trying to keep the board size down and SMD also helps with this. They haven't turned up yet, but they're on their way. I'm also working on 2 other projects at the moment, a rework of a 4164 DRAM chip tester that gives a simple go/no-go and a reverse engineer of the Amstrad 464 Diagnostic board with maybe a rewrite of the ROM to test the extra 64k on a plus....
Anyone interested in any of that?
Rob
The diagnostics board would be nice.
I have the diagnostics board Habi made for the PCW, I have used it several times now and I discovered my main PCW has a faulty ram chip.
So it may save time when diagnosing a CPC.
Is there a dump of the rom from the diagnostics board?
You mean the rom of the diagnostics 'cartridge' for the PCW?
Here is the original 9512 test cartridge rom: http://habisoft.com/pcwwiki/doku.php?id=en:hardware:perifericos:pcw_9512_test_pcb
Here is Habi's combined test cartridge for PCW: http://habisoft.com/pcwwiki/doku.php?id=en:hardware:perifericos:pcw_universal_test_pcb
I don't know whether there's a dump of the 8000 series test pcb roms, but I'll take a look around.
I haven't dumped the ROM ..Yet. But I will do.
Regards
Rob
Ain't she cute!
Rob
Coooool!
I cannot read the eprom text. It would be nice if you can take some high res pictures/scans of both sides for the wiki.
My bet is that it's a standard 27xxx eprom, but better safe than sorry before dumping it.
Its a 2764
rob
Okay guys, initial tests look excellent, the banks are working (0-7 and 8-15) the ROMs can be seen and they disable okay.
I have a couple of fixes to do to the boards that I've done a manual fixup on (nothing to do with the schematic per se, just my lack of understanding of Altium's Bus naming conventions) and then I'm going to get them redone now I know they work.
I have updated the schematic and will repost the new one once I have the final boards in a week.
I reckon if I'm going to sell them it will be as fully assembled units as people don't like soldering SMD as much as me, and they'll sell for about 35/40UKP.
If anyone is interested in that please PM me.
Once its built I'll put a video up on my YouTube channel : https://www.youtube.com/channel/UC0vHFBNVST8_xzUoRqIbz6Q
Rob
PM sent with regard to a fully assembled unit :)
Boards now ordered, should be here mid next week.
Rob
Layout pictures? How small have you got the board down to?
Bryce.
Pic attached. Board size is 96.78mm x90.17mm
Regards
Rob
Top marks. Really nicely done.
Put me down for a blank PCB if you are selling them like that.
Bryce.
Edit: Just noticed a minor mistake. C30 and C138 should have been physically on opposite sides of the PCB, but I doubt it matters. I'd leave one off completely and use a single 47µf capacitor instead.
Edit 2: Just noticed a bigger mistake. The EPROMs with the capacitors across VCC/VSS don't seem to be connected to the ground plane??
Thank you for your kind words!
I've actually seen ROMboards that dont use any capacitors at all on them! In fact during testing I didn't even bother soldering any of the caps on and I never once got it to crash. They're really there for just belt and braces.
I'm going to say this again : I'm not an electronics genius like you, I'm just a hobbyist with an interest in fixing stuff although I do appreciate your comments.
If I sell the 10 I've ordered then I'll order some new boards and make that change :-)
Regards
Rob
Hi Bryce,
They're definitely connected, double checked on board I've got here, attached a close up of the caps on the board....
Regards
Rob
Quote from: The Equalizor on 16:11, 21 March 18
I'm going to say this again : I'm not an electronics genius like you, I'm just a hobbyist with an interest in fixing stuff although I do appreciate your comments.
I'd give you a job. I've seen worse from people who get paid to do it!
Good to hear that the GND is connected. I was just suspicious because the trace from the VSS pin goes seperately through the ground plane.
Bryce.
Yeah Altium does some stuff in strange ways. I use the Autorouter a lot and then correct the insanity that ensues as much as I can.
I'll let you know when the blank boards turn up and I've built one and tested it. If they work correctly I'd actually like to donate one to you in recognition of the hard work you do on this board, I'd be very happy to do that.
Regards
Rob
That's very kind of you.
Regarding the Altium strangeness (of which there's lots). As far as I can remember, you need to rename the NET between the capacitor and VSS to whatever the ground plane is called and it will integrate it into the plane automatically. (or I may be thinking of a completely different routing program :D )
Bryce.
Great job with the Romboard, I'd like to order one, too! :)
Mmmm PCB Goodness :-) just in from China!
I'll be building the test one tonight, I'll see how that goes and let you guys know.
Regards
Rob
That looks really good Rob.
Well, as long as it works as good as it looks I'll be happy!
But thank you :-)
Rob
Quote from: The Equalizor on 15:08, 28 March 18
Mmmm PCB Goodness :-) just in from China!
I'll be building the test one tonight, I'll see how that goes and let you guys know.
Regards
Rob
Some of the capacitor footprints look to be very small, what package size have you gone for?
Bryce.
Gesendet von meinem Motorola DynaTAC 8000x mit Tapatalk
0805 ceramic multilayer. I didn't get too excited about them as some romboards don't even have them, but I wanted *something* on there. The original Rombo had 10nf caps on 4 of the IC sockets
Regards
Rob
And it was all going so well...
The new board [updated schematic attached] has a very odd issue. If I select Bank 1 [8-15] all ROM slots work great and can be switched on and off. If however I select Bank 0 [0-7] ROM slot 2 doesn't work, unless I turn on DIP switch 3 as well as 2.
The only thing I changed before generating the PCB was change around the Bank Selector pins as the way it was before pins 1 & 2 selected bank 1 and pins 2 & 3 selected bank 0.
Any ideas guys?
Rob
Maybe it needs more decoupling caps.
Are the power traces really as thin as they look on the picture earlier in the thread?. The rombo board may not have had many caps, but it had decent sized power rails.
It did, but why would that only affect bank 0 and not bank 1. Also why would it work when DIP2&3 are both on in Bank 0 but not need DIP3 on when its set to Bank 1?
What do you think?
Also the schematic for the previous one before I swapped those bank pins around doesn't exhibit the same issue...
Weird huh
Rob
Ooops, did I forget the sarcasm tag?
I think it's a miracle the board works at all. Can you get your PCB package to highlight the VCC (+5) power rail, and post a picture of the board. Can you measure the vlotage on the ROM furthest from the connector with the board fully populated.
Do you have any test equipment, probably need a scope, to see how dirty all the power rails and signals are with it fully populated with ROMS.
If you shuffle roms around or only fit one at a time, does the fault change?
Im pretty sure its not a power thing - it does it with only 1 rom in the ROMboard in slot 2, and only does it when in the bank 0 position. Thats what I mean when I say it doesn't make sense.
Maybe I'm wasting my time and should hand it over to someone with more knowledge than me.
regards
Rob
Have you done a thorough visual inspection of the soldering around the dil switch and the link, the relevant traces do go very close to each other around there.
Had a look under the Amscope and it looks okay to me.
Thank you for the suggestions though.
Rob
Thats weird. I works great on a standard CPC6128, All slot, both banks. I'm gonna etst it on another plus in case my "modified" one isn't happy for some reason.
Regards
Rob
I think I'm going to take Ian's advice and shore up the power traces s between the components and see if that helps it behave a little better. No point in having an unreliable ROM board...
Rob
Quote from: The Equalizor on 15:57, 28 March 18
0805 ceramic multilayer. I didn't get too excited about them as some romboards don't even have them, but I wanted *something* on there. The original Rombo had 10nf caps on 4 of the IC sockets
Regards
Rob
I meant the electrolytic capacitors. They seem to have 0805 footprints too?? What are you using there?
Bryce.
Gesendet von meinem Motorola DynaTAC 8000x mit Tapatalk
There is only one electrolytic cap on the Rombo and my one came off years ago and worked fine without it but for the new board I'll be adding one in.However IanS's expert advice was pretty much correct here. After shoring up the traces between thr 8 rom sockets, the 5 logic ICs and the 4 decoupling caps its working great. Also once again, Altium has screwed me by not connecting the 2 VCC nets together on the ICs with hidden nets. Connecting all those up has fixed the issue completely.
Just gotta work out now how to tell Altium to do thicker traces for VCC in the PCB layout.
Cheers all for your help, especially IanS and you Bryce,
PS Excuse the um inventive bank select jumper....
Rob
Quote from: The Equalizor on 00:18, 31 March 18
After shoring up the traces between thr 8 rom sockets, the 5 logic ICs and the 4 decoupling caps its working great.
Good to see it's now working, thanks for the update.
It was possible to connect two original Rombo ROMboard's, one over the other, so that you had 16 rom's in one box,
but if you did, it was impossible to operate the bottom rom switch, so I had to move the switche's to the lid.
It would have been nice if it had been easy to move them.
It was also possible to connect a RAM-ROM, useful if you were to develop a rom without having to burn one each time
you wanted to test it, but not very usefull today.
Equalizor please keep that in mind while developing your romboard.
Okay guys, they're finished, pics attached. Can anyone who's interested in one please PM me again.
Edit : I should point out that the ROMs aren't included and that the cost will be £40.00UKP including shipping to the EU and £45.00 UKP for areas outside.
If anyone also wants ROMs supplied with it, I can do that too. I would charge £3.00 per ROM and that is obviously for supplying the ROM and programming the Image.
Cheers
Rob
Slightly off topic, but which Rom is it that gives the |help extension? I've just built a version of bryce"s megaflash and would like to get the most of it with my 464 with 664 firmware/basic.
Quote from: Chinnery on 21:09, 09 April 18
Slightly off topic, but which Rom is it that gives the |help extension? I've just built a version of bryce"s megaflash and would like to get the most of it with my 464 with 664 firmware/basic.
Looks like the standard output from Utopia.
IanS has this annoying habit of being right ;D , and this time...yup, he is again. It's Utopia, by Arnor.
Rob
Hi Chinnery,
You could also use DES.
Using the Rom option (from the Desktop) in DES provides the user with two list boxes. The left box shows all the Roms connected, the right box shows the commands associated with each Rom. A mouse is not necessary as the function keys are predefined and can be used to scroll up and down the list of Roms, to execute any Rom command simply press "R".
Have a look at page 14 of the manual:
http://www.cpcwiki.eu/imgs/7/78/DES_User_Manual.pdf (http://www.cpcwiki.eu/imgs/7/78/DES_User_Manual.pdf)
The Roms (2) are available from here: http://www.cpcwiki.eu/index.php/Desktop_Environment_System (http://www.cpcwiki.eu/index.php/Desktop_Environment_System)
However, I am unable to check DES and megaflash compatibilty as I don't have this hardware.
Has anyone tried this combination?
Cheers,
Peter
@ComSoft6128 (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2226) , @The Equalizor (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2279) , @IanS (http://www.cpcwiki.eu/forum/index.php?action=profile;u=629)
Thanks for the info - DES looks kinda fun to have in a rombox - I'll write them both in and see what happens :)
@thread - sorry for hijack... as you were now. nothing to see here. move along. thank you. :D
Quote from: The Equalizor on 22:07, 09 April 18
IanS has this annoying habit of being right ;D , and this time...yup, he is again. It's Utopia, by Arnor.
Rob
Actually all Arnor ROMs include the Help command. So having Maxam, Protext, Utopia or whatever installed is enough.
Bryce.
Just a quick heads up to the people that have ordered Rombo Redux boards, just waiting on the anti static bags and jiffy bags to arrive, then I'll be in touch for shipping details and payment.
regards
Rob
That's great, I am really looking forward to getting one!
Well, this is your one, waiting for its new home!
Regards
Rob
Wow! What a beauty :-* - terrific job!! :)
Okay the testing issues that I thought I had don't exist on either of the CPC6128 machines I've tested it on, only on my heavily modified Plus at home. I will be retesting on another Plus today and one of the boards main hardware gurus is actually building a ROmbo Redux and will give it a proper independent test, so I can be sure they're okay -I don't want to send then halfway round the world only to find they have issues. I will update this thread with any results shortly.
Rob
What mods are installed on the heavily modded Plus?
Bryce.
Well, probably the dogiest one would be the cartridge slot extension that replicates the cartridge slot from the side of the PCB to the top of the custom case. Its using standard ribbon cable but separate strands. Also I may have, ahem, cut off the 2nd drive connector on the mainboard.
Rob
Confirmed working - its my Plus at home that's having issues. Tested on 2 x 6128's and one 6128 Plus. my one at home wouldn't even boot the CPM roms whereas the one here does!
I'll be in contact with the people that want one of these shortly.
Regards
Rob
New boards are in.
Now what I'd really like is for someone other than me to further test it.Ive given it a good run through and found no issues but I don't want to send these half way round the world and then find some stupid glitch with them.
My offer is this. If someone out there who is reasonably technical and experienced with ROMs and ROMboards wants to test it for me, I'll send them a free one. You'll need to be able to prove your credentials in the aforementioned area, and I'll be sending a bare board to Bryce regardless.
Any offers?
First batch ready for their new homes :-)
I'm waiting on new edge connectors and then I'm planning my second batch. If anyone is interested in one of these who I haven't contacted today, please PM me.
Regards
Rob
I was lucky enough to be able to test this board before release, so think it's only polite to write a mini review here.
<TLDR>
It's a great bit of kit.
</TLDR>
When I got the board my first impression was how tidy it was. Most of the SMD components were hidden away safely under the sockets protecting them from ham-fisted handling, the dip switches are a neat idea and the fact it connected to the CPC via a ribbon was great - no more wear and tear on my poor CPC edge connector. It is a well thought out design in my untrained opinion.
In use, I have given it quite a test in all of my non-plus machines and haven't found any issues. Even with a bad rom inserted, it was easy to debug using the dip switches to disable all roms and turn them on one by one to work out which was bad. In this instance it was a utopia rom that had a header which I forgot to remove, causing the CPC to reboot continuously. I tried this bad rom in another romboard and got exactly the same symptoms.
It's worked great with my "fake" 664 and 6128 as both banks 0-7 and 8-15, and my 464 as banks 0-7. I've chained it with my speech synth, DDI3 with 512k ram, multiface 2 clone (not all at the same time I have to say) - everything works great. The DK Tronic's speech synth rom now has pride of place in the romboard and is easy to toggle on or off.
I've tested it with 16k and 32k eeproms (using half the 32k one), and 32k proms (again using only the upper half). Things just seem to work.
The only issue I can see with this is not being able to burn your own roms, or being scared of doing so/not understanding how. My eeprom programmer was only £35 from ebay and it is pretty straight forward to use. I can give some help for those wanting to get into the fun world of roms - I'll even burn and post them for cost to get you going if you're really scared.
I've also burned a couple of games to rom - games I always go back to. Being able to type |ManicMiner or |Thrust to get instantly into the game is just great. I even had a quick 5 mins using future os just to test.
So yeah. A great board all round. Compatibility seems high with both software and hardware.
Well, that went well!
The first batch is now sold out!
I've ordered some new parts which I'm expecting in a couple of weeks, production will begin once they've arrived.
Regards
Rob
Congratulations to pulling it off - it works great!Thanks a lot!
Btw, anybody has Fruity Frank ROM and/or Sorcery?
Quote from: LambdaMikel on 07:09, 03 June 18
Btw, anybody has Fruity Frank ROM and/or Sorcery?
All currently available game ROMs can be found here: http://www.cpcwiki.eu/index.php/ROM_List
Neither of the games you are looking for are there though and I doubt Socery would fit on a single ROM.
Bryce.
For those interested I've just made a video showing a time lapse of me making one of these awesome boards :-) These usually take an hour to build.
Its on my channel and I've linked the video below. If you like videos of CPC Hardware stuff I'd really appreciate it if you subscribed to my YouTube channel.
Regards
Rob
https://youtu.be/v7xvqmfcbBI (https://youtu.be/v7xvqmfcbBI)
Some decent soldering skills in there!
Thank you :)
It helps that my dad was an electrical engineer and taught me how to solder when I was 8 :) He also recommended the JBC soldering station that I use for this stuff.
Cheers
Rob
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Great video, I wish I could solder like that!
Although, if the video really is sped up 800x and is 7 minutes long, then the board must have actually taken 93 hours to build?! :o
Well done, you spotted my, um *deliberate* mistake.
Yeah obviously its not 800x, it's actually 800% :-) that's late night video editing for you.
Rob
It took an hour to build basically.
Rob
Quote from: The Equalizor on 22:52, 04 June 18
For those interested I've just made a video showing a time lapse of me making one of these awesome boards :-) These usually take an hour to build.
Great video indeed - I had no idea one can solder these SMD components by hand like that (I always thought it involved using a paste and one of these ovens). Thanks for sharing! :)
Oh yeah with the right iron and tip, magnifiers (stereo preferably) and flux, (never forget the flux, that really, really helps), its a piece of whatsit. I rarely use hot air to solder smd stuff, just to desolder.
regards
Rob
Excellent video Rob. Wish I had skills like that.
It's never too late to learn smd soldering though and you don't need a huge outlay.
A hot air station is pretty much essential if you're going to be desoldering a lot of components, but again you can get very good quality stations for less than £300 quid now. I use the Quick 861 and it's great.
If anyone wants any advice about doing smd I'm very happy to help. We can either start a new thread or pm me.
Rob
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And just to prove you don't need a 400 pound soldering station to do a lot of smd work here is a pic of a board with chips fitted using the 50 quid ts100 iron..
Rob(https://uploads.tapatalk-cdn.com/20180605/499f3d2da51f6de83ae67ac246ab9c99.jpg)
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To be fair the TS100 is a *beast* of an iron that shouldn't be as good as it is (or equivalently, that the low-end Hakko stations have been a rip-off for years.)
For SMD though all you really need is the right tip and plenty of extra flux. Don't get tricked into thinking "fine pins need a fine tip"; the fine conical tips are the *worst* (they don't transfer heat fast enough). Get a chisel or similar tip that gives you an edge not a point (the BC2 tip is the best choice out of the available ts100 tips imho) and things will be so much easier. Especially when you realise you can flood the pins with flux, heat a bunch of pins simultaneously with the tip, and the solder will magically go to the right places.
Ah, the TS100 with BC2 tip, wouldn't leave the house without it. Never seen one with a see-through case though, mines just a plain black version.
Bryce.
It's china, you can buy replacement cases in various colours (not the one I want, though :doh: )
Just wanted to say thank you to Rob for taking the the time and trouble to produce and make the board. It is a great credit to him and is an excellent piece of work.
Quote from: The Equalizor on 21:27, 05 June 18
And just to prove you don't need a 400 pound soldering station to do a lot of smd work here is a pic of a board with chips fitted using the 50 quid ts100 iron..
Rob(https://uploads.tapatalk-cdn.com/20180605/499f3d2da51f6de83ae67ac246ab9c99.jpg)
Sent from my SM-G965F using Tapatalk
I never had one in my hands but surely it looks super-cool. I mean, a soldering iron with OLED screen!
They're a great little iron actually. Powered from USB it's a bit weak, but if you use the PSU they supply with it then it's perfect.
Bryce.
Best results are achieved if you run it from 24V. On 12V it's just "okay". 5V is only for people who hate themselves and the thing they're working on :laugh:
Is this even possible on usb. A ts100 65w iron running on USB 5v? Wouldn't that be like more than 13amps? I'm not an electrical engineer but I can't see one of these irons being run from USB.
Bryce, are you thinking of those actual USB soldering irons that come with an adaptor?
Rob
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The 65W is only possible at 24V, it provides a lot less heat at 12V. I may be thinking of a different iron on USB though, as I have one of those too.
Bryce.
Edit: Just checked the manual: At 12V it is only a 17W iron.
I use mine on an old laptop power supply and that's perfect. 19v@3.16a it really hits the sweet spot. If you guys are good ill post the pic [emoji846]
Rob
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If you were waiting for a Rombo Redux with a Thru-connector and a Pause button, well the prototype is in and works great! I'll be geting the final boards ordered this week. As per usual PM me if you're interested.
Rob
Quote from: The Equalizor on 00:33, 28 June 18
If you were waiting for a Rombo Redux with a Thru-connector and a Pause button, well the prototype is in and works great! I'll be geting the final boards ordered this week. As per usual PM me if you're interested.
Rob
I'd like one please. Pm sent.
This is really the missing link in my 464 puzzle.
Now I can connect from RomboRedux Deluxe to LambdaBoard, add M4X boards such as LambdaSpeak, and then DDI3 at the end.
Perfect!