CPC464+ build thread

[darkhalf]

Got an ebay CPC464 plus on the way. However it doesn't come with anything else

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Found some of the info was scattered over the place, so putting into one thread here

So far ordered 5V 3Amp power connector (noting 5.5mm/2.5mm)
https://www.cpcwiki.eu/index.php/Power_Supply_for_CPC_and_CPC_plus

This one from ebay and needed to cover the 2.5Amp needed by the plus
https://www.ebay.com.au/itm/332795112867
Ordered PCBs and parts for CPC plus cartridge

Xilinx version (full ACID emulation)
https://github.com/f1ac0/CPC-plus-cartridge

Chinnery version (ACID workaround)
https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/amstrad-gx4000-plus-cartridge-pcb/

https://www.cpcwiki.eu/index.php/464Plus_Conversion

Ordered parts for 64KB upgrade and drive parts (most bits through digikey) and 41464 memory from an local ebay electronics seller
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https://www.ebay.com.au/itm/113748919765
Drive: NEC chips

https://www.aliexpress.com/item/1005001968866175.html
Drive: SED9420C chip

First step is the monitor. We never got the plus models delivered here, so I need to convert the 8 pin to 6 pin plus audio output
https://www.cpcwiki.eu/index.php/Connector:Monitor

Connectors from jaycar and using part of an old joystick cable, which had enough cores (and matching colours) that we needed. So RGB and then orange for sync, grey for luminance and black for ground.

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Double checking pins twice, since the 6 pin CPC connector uses ground on the side
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[GUNHED]

You need a Cartridge to boot. The green screen color is normal without Cartridge.

[darkhalf]

You need a Cartridge to boot. The green screen color is normal without Cartridge.

Thanks but I know that already. Might be worthwhile reading posts properly before commenting 
https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/cpc-plus-cartridge-replacement-one-more/1525/

From info on Kevin Thacker's site I was able to determine that green screen for the CPC 464 plus was the only sign of life that can be shown without a cartridge. So it was a less risky purchase knowing this
https://cpctech.cpcwiki.de/docs/cpcplus.html

In this post I discuss building both the Chinnery and f1aco cartridges to use. So PCBs and parts are on order.  I needed to install Kicad and create gerbers for JCLPCB ordering
https://www.pcbway.com/helpcenter/technical_support/Generate_Gerber_file_from_Kicad.html

There were other options like https://hobbyretro.com/en/retro/cartridge-amstrad-plus-2 and multi selection version on ebay, but exchange rates and shipping are expensive in Australia

ACID ASIC chip decoding by Nocash emulated in the f1aco PCB using Xilinx 9536
https://www.cpcwiki.eu/index.php/Amstrad_Cartridge_Identification_Device
If still needed for this investigation, I can get some scope traces from the Plus without the ACID connected

I am also building the flip flop version cartridge. Appears to be a simple setup with by toggling SIN output based on CCLR input to the ACID. I read that this doesn't respond well to soft reset, and note there is no reset line on the cartridge slot either
https://www.cpcwiki.eu/index.php/Connector:Cartridge_Slot_(CPC_Plus_only)


Anyway my intention is to put all useful CPC plus info in the one thread. During my investigations to get this working I noticed that information is in different posts and wiki pages and am grateful for all the work which has been done so far. I could not yet find a scanned CPC plus users manual (only service manual)

[darkhalf]

More stuff for cartridge downloads (converting BIN/CPR)
http://www.cpcmania.com/cprtools/cprtools.htm

CPR file format
https://www.cpcwiki.eu/index.php/Format:CPR_CPC_Plus_cartridge_file_format

Background info on CPR
https://www.cpcwiki.eu/forum/technical-support/purpose-of-the-cpr-format/msg228362/#msg228362

CPC wiki page for GX4000 megadownload link
https://www.cpcwiki.eu/index.php/Converted_GX4000_Software

Other programs for plus only (select CPC+ and search)
https://www.cpc-power.com/index.php?page=database

As for the ROMs for the Chinnery board will be using 27C2001 (256k) and 27C4001 (512k) can be used for larger carts. Using a GQx4 programmer for programming the chips
https://www.aliexpress.com/item/1005004860711234.html

Also planning on using the M4 board via MX4 connector for cartridges. Parts on order for the Centronics connectors
https://www.aliexpress.com/item/1005003161799870.html (2x 25 pin IDC with cable for MX4)
https://www.aliexpress.com/item/1005005637138533.html (50 pin IDC male to cable for MX4)
https://www.aliexpress.com/item/1005005637138533.html (36 pin IDC male to cable for external floppy B)

Amstrad released the CPC464 plus with one game controller. This unit has none, so purchased via ebay from the UK. 16.50GBP plus taxes and post. Looks a bit grubby so will use some orange oil extract to clean it carefully

[dragon]

Don't left these:

https://www.tradera.com/item/3018/582972453/amstrad-cpc-plus-gx4000-game-cartridge-inkl-programmering-cpc-

https://www.tradera.com/item/3018/435351039/amstrad-gx4000-game-cartridge-inkl-programmering-cpc-cpc-plus

[dragon]

Manuals are in acme and in cpcmania:


https://acpc.me/ACME/
http://www.cpcmania.com/news.htm

[darkhalf]

Thankyou! Yes this is an awesome collection
ENGLISH/464PLUS-6128PLUS_1990[ENG](acme).pdf]https://acpc.me/ACME/LITTERATURE_MANUELS/%5BENG%5DENGLISH/464PLUS-6128PLUS_1990%5BENG%5D%28acme%29.pdf

Also some other links I found with books
https://archive.org/details/cpcbooks?&sort=date

Some other cart images for diagnostics which I will start with

Amstrad Diagnostics
https://github.com/llopis/amstrad-diagnostics/

Arnold 5 diagnostic ROM
https://www.cpc-power.com/index.php?page=detail&num=9627

512K TOSEC named files (BIN format). Some of these I converted from CPR format but not tested yet

[darkhalf]

128K TOSEC named files (BIN format). Some from usual spots and others from CPCPower

[darkhalf]

So a few bits have arrived, including the machine. Power LED works, cassette forwards, backwards works. Play works with no cart which is a bit weird. Connected up the CTM644 and looks like it was a grey screen (not a green screen) so hopefully once I've got a cart I'll get something showing up. It needs a bit of a clean, but no scratches or any other marks. Waiting for PCBs, sockets and EPROMs to build the carts

[darkhalf]

More updates. The case had evidence of liquid on the outside, so I've opened it up and it needed a fair bit of clean 

I've used diluted vinegar over the case and the keys. The plastic underneath has a black paint like coating which dissolves with vinegar and IPA!

After further cleaning through all the keys I've managed to get it tidier

[darkhalf]

Some parts arrived on Tuesday from JCL PCB for my ACID Xilinx emulator boards. TL866II plus was used to program the memory chips and Xilinx parallel programmer with ISE 14.7 and IMPACT used to program the XL9536

Testing didn't go so well with intermittent crashes on boot, or sometimes it would make it further and then stop

[darkhalf]

More investigation with random lockups. Sometimes memory tests would pass and other times it would lock up and fail completely

Z80 test on Arnold diagnostics were passing, and usually the memory test would run time after time with no issue. Other times with straight bootup, problems

I needed to wait for the other ASIC nobbler cartridge parts  to arrive

[darkhalf]

So I built up the other ASIC nobbler boards using the parts I had here and then the next day the 27C1001 EPROMs arrived!

Success! Basic is now booting, and no more crashing. So I have a problem with the Xilinx chips, which need further looking into

https://github.com/f1ac0/CPC-plus-cartridge

I'm using 1uF capacitors (but the BOM has 2.2uf) but that shouldn't matter

The instructions menion "Macrocell power setting" can be "Low" an "Slew rate" to "Slow". There is only one pin out, which is PinSIN, so I've set this up

NET PinSIN LOC=P32 | SLEW = SLOW | PWR_MODE = LOW;

[darkhalf]

So not sure what is wrong with that part of the Xilinx setup part of this. If any one has any ideas I'm keen to hear. 

Xilinx CPLD chips can be quite current hungry, and also have a dendency due to this to ground bounce outputs, but there is only one output here, so it should not be that

I will need to check the power levels at the cart port to see if they are similar to the ASIC nobbler board, and if extra power/grounds are required

[darkhalf]

Anyway continued on with diagnostics and all was good, except noticed some issues with the keyboard. Most of the keys were not working

So pulled apart the keyboard and membrane. It was filthy! I've washed that with just some dishwashing liquid, and then cleaned it up again with IPA and then tested again with no joy

Fearing the ASIC PIO outputs to the keyboard were dead, I checked all of these and they were fine. Then next I removed the NR02 pull up resistor pack. Still no joy

So then I grabbed the keyboard from my CPC6128 which was the same fix (but different key layout) and that passed the tests

So I went through the traces on both of the membranes on this CPC464 plus, and there were breaks everywhere. Way too difficult to fix

So unfortunately there is only one place that sells them these days for Plus Models for a grand total of 69EUR shipped!
https://www.sintech-shop.de/tastaturfolie-keyboard-membrane-fuer-amstrad-schneider-cpc-plus-464-und-6128-neu-produziert/a-10823

I'm now waiting on that to arrive, and my bank balance needs to recover 

[darkhalf]

Next time for a memory upgrade, whilst we wait for the keyboard!

https://www.cpcwiki.eu/index.php/464Plus_Conversion

I've moved into the shed with the GT64 and decided to desolder all the solder pads for my future upgrades, and put in sockets. I removed the original RAM D4146C and put in the ones I had purchased to tested they works (so just 2 at a time)

Once that was all good, then I followed the AA90 upgrade guide and installed the rest of the memory and added the resistors. Various memory tests later and we have a 128K RAM active 

[darkhalf]

The next step after this was AA91 and populate the resistors, capacitors and chips for the floppy drive controller

The SED9420C could only be found on AliExpress and NEC765AC-2 on ebay. I've resocketed the SED in my CPC6128 for testing the AliExpress parts, and used a Zaxon DDI1 board for testing the ebay parts prior to installing into the unicorn which is this CPC464 plus

All fortunately have tested okay with both drives doing full verify. The SED chips were a 'pulled' part and probably the NEC chips too, but they work and I few a few spares if required later on

I cannot really test the drives without the keyboard. Amstrad diagnostics is showing a FDC controller which is nice. So the next step was trying to figure out how to connect the Drive A and Drive B

For drive A instructions here:
https://www.cpcwiki.eu/index.php/DIY:Floppy_Drives#Multi-Adaptor_Cable_for_External_Floppies_.2F_HxC_emulator

For drive B I used a 36 pin Centronics edge connector (and plug with ribbon) from Aliexpress. The instructions are a bit confusing but managed to figure it out and hopefully got it right using the above, and the CPC FAQ below
http://genesis8.free.fr/amstrad/faq/amstrad.php#A322

Both buzz out the same to the Goteks, so I just need to check them once I have a keyboard

[darkhalf]

For the expansion port to make a MX4 connector, I've used a 50 pin IDC - IDC connector, and also 2 x 50 pin to ribbon centronics male connectors. 

Also in the picture are the bits (LHS) used for the PCB Centronics female 36 pin floppy edge connector. 

For the cable 36 pin Centronics male floppy connector to 26 pin cable and 34 pin IDC (3 pin offset LHS side) is used. 

Now we connect our MX4 backplane and try the Dandanator board

After this we try the M4 board and also success, with WIFI to the cpc464 plus enabled and working

[darkhalf]

My next test was to try out the upload cartridge option of the M4 (web interface) but not so much luck

https://www.spinpoint.org/cpc/m4info.txt

Added option in web interface to downgrade romboard to 16 roms, to be able to fit 512 KB cartridges.

Support 512KB cartridge images (mainly used by CPC+)
Added option to upload & start cartridge images via web interface�

I've tried several, including 512K Puzzle Bobble v1.2 (UK) (2022) [CARTOUCHE].bin but get a blank or after reset a striped screen like pictured. Actually after uploading puzzle bobble, I rebooted an got a corrupted Ghosts 'n Gobblins. So the flash is not completely uploading, or the M4 needs a reset
 
Might be a problem with the ACID nobbling on the cartridge (noted issue with reset) and I might need to figure out why the Xilinx ACID emulation is a bit flaky

[darkhalf]

After the keyboard arrives, and drives are confirmed, next on the radar is plus compatible memory upgrade for use with Symbos

I've built the Revaldino boards before, but the expansion is disabled with the ASCI registers mapped in
https://github.com/revaldinho/cpc_ram_expansion/wiki/Universal-Amstrad-CPC-RAM-Card

So a 1MB module will be on the shopping list
https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/gemini-1mb-ram-expansion-for-amstrad-plus/125/

[darkhalf]

Okay another update. Keyboard membrane arrived from Germany this week. Installed and fitted okay. Next ran through keyboard tests and all good

Next up was to test both of the drives which I had connected. One is a Gotek on A (DF0) and also a 3.5" on B (DF1). For now I've chosen to power both externally even though the internal supply should be able to manage it

After setting correct jumpers on both, they work fine

[darkhalf]

Next up is testing the cassette. Belt looks good and I've cleaned the heads and pinch roller. Sacrificial cassette is some strategy game Holdfast. That is all loading okay

After this we have to modify the case:
1. Mark out the outline of where the DRIVE B Centronics connector will so. Use other ports as a guide
2. Dremel the plastic within the outline and then file it carefully
3. Dremel the corner off the cassette hinge so it doesn't hit the Centronics connector

Then I have fed the internal FDD cable via the expansion port and put some tape around it to prevent rubbing issues. Final result as we can see

Next up I've burnt some more cartridges. Also re-tested out the Xilinx noAcid ones again, and these work now?! Maybe it was the memory replacement or some other magic but those work now. Anyway all successful with 128K onboard RAM, 2 x drives, cassette, cartridges and I've also got the expansion board (512KB external RAM board and M4 board) working 

[darkhalf]

Had some updates on other threads, which I'll tie back into this one. Started making some cases for the cartridges now

My mate did some 3D printing for cartridge cases:
https://www.thingiverse.com/thing:4687341?fbclid=IwAR2vJCHgjdjzslvOI-iG8x1cnD_bCif3J7gMZyZ123A0EtN1mvXmwhNfl_M

This one ended up a bit thin and board not fitting properly so we found the next one V2
https://www.thingiverse.com/thing:4943077?fbclid=IwAR16Wql5rujVw-XP5woCWENdK5h4uDORDyf5xeZ6Q4Wqy5hwvv0TeNDYgWw

The carts needed a bit of grinding and filing to fit properly. Mainly the entry point, and also the bottom 'slide' grooves needed some extra clearance

Got in touch with @overange and received his FLASH+ cartridge and adapter. Unfortunately the adaptor received was for a VECTREX so he is sending another one through. 

This will allow us to reflash the cartridges without opening the case
https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/amstrad-gx4000-cpc-464-6128-plus-reflashable-flash-cartridge/

[darkhalf]

With the revaldinho board fitted for 512KB extra memory, the CPCPlus would lock up often
https://github.com/revaldinho/cpc_ram_expansion/wiki/Universal-Amstrad-CPC-RAM-Card

So time for the Gemini RAM board. I've gone the 1MB version, since this is the limit of symbos
https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/gemini-1mb-ram-expansion-for-amstrad-plus/150/

Attached: Amstrad CPC Plus - CPCPlusDSK.zip
Various Plus DSK downloads either via youtube, CPC Power or CPC Rulez

Noted: This one not working (stuck at main screen)
Mr_Heli__(2022-04-27)__(Enhanced_512K_Edition)__FRENCH__CHANY-NPS.dsk

[darkhalf]

Attached: Various plus demos I've found