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Repo MVS Cart PCB Discussion

Code: 
LS161
-----
PIN 01 <=> PIN 08 on HC14 (left), PIN 01 on LS374's #1 to #4
PIN 02 <=> PIN B25 Edge Bottom (ROMWAIT)
PIN 03 <=> nothing?
PIN 04 <=> nothing?
PIN 05 <=> nothing?
PIN 06 <=> nothing?
PIN 07 <=> PIN 10 on LS161 (same ic), PIN 12 on HC14 (left)
PIN 08 <=> GND
PIN 09 <=> VCC (via jumper to right of ic)
PIN 10 <=> PIN 07 on LS161 (same ic), PIN 12 on HC14 (left)
PIN 11 <=> nothing?
PIN 12 <=> nothing?
PIN 13 <=> PIN 13 on HC14 (left), PIN 11 on HC373A (top)
PIN 14 <=> nothing?
PIN 15 <=> nothing?
PIN 16 <=> VCC

HC14 (left)
----
PIN 01 <=> PIN A56 Edge Top (SDROE)
PIN 02 <=> PIN 03 on HC14 (same ic)
PIN 03 <=> PIN 02 on HC14 (same ic)
PIN 04 <=> PIN 01 on HC373A (top)
PIN 05 <=> PIN 11 on HC14 (same ic), PIN A48 Edge Top (SDPOE)
PIN 06 <=> PIN 09 on HC14 (same ic), PIN 01 on LS374's #5 to #8
PIN 07 <=> GND
PIN 08 <=> PIN 01 on LS161, PIN 01 on HC373A (bottom), PIN 01 on LS274's #1 to #4
PIN 09 <=> PIN 06 on HC14 (same ic), PIN 01 on LS374's #5 to #8
PIN 10 <=> PIN 11 on HC373A (bottom)
PIN 11 <=> PIN 05 on HC14 (same ic), PIN A48 Edge Top (SDPOE)
PIN 12 <=> PIN 07 on LS161, PIN 10 on LS161
PIN 13 <=> PIN 11 on HC373A (top), PIN 13 on LS161
PIN 14 <=> VCC

Will do a couple more tomorrow
 
Last edited:
Fluffy said:
A quick test to convert the Verilog code for the PCM into discrete logic chips. I am not sure if I've got all inverters correct, you can probably use smaller latches, and I'm sure you could optimise out the counter... I'll have to double-check everything against the timing diagrams.
This is still going to take quite some space compared to a small CPLD.

The talk about the STM32 makes me think if you could run an OGG decoder on a microcontroller and then stream the result over an ADPCM channel to the NeoGeo. You'd ignore the address and just write to the data bus. Though probably only interesting for homebrew...
Click to expand...
Why not use Furrtek's PCM repro? https://www.tindie.com/products/furrtek/pcm-chip-replacement/
 
Fluffy said:
Thanks so far! I'll update my notes with what you found.

Is it possible that this one goes to B24 68KCLKB ?
Click to expand...

Yeah I think you are right, here is a pic

Lansquenet_2004_bootleg1_b1_back.jpg
 
Fluffy said:
Thanks so far! I'll update my notes with what you found.
Click to expand...
I just realized there are 2x HC14s on the board after looking at your picture again. Its super hard to read a couple of the labels on my langsquenet board and thought there was only one of them. In the trace for the LS161 and HC14 above, the HC14 referenced it always the left one. I've updated that post to reflect that.
 
Code: 
HC14 (right)
-----------
PIN 01 <=> PIN A55 Edge Top (SDRMPX), also goes to a cap(?) right below it with the other side being ground
PIN 02 <=> PIN 03 on HC14 (same ic), PIN 11 on LS374's #7 and #8
PIN 03 <=> PIN 02 on HC14 (same ic), PIN 11 on LS374's #7 and #8
PIN 04 <=> PIN 11 on LS374's #5 and #6
PIN 05 <=> PIN 02 on LS374's #1 and #5, PIN 19 on LS245 (top)
PIN 06 <=> PIN 19 on LS245 (bottom)
PIN 07 <=> GND
PIN 08 <=> nothing? (checked 4 times)
PIN 09 <=> PIN 09 on LS374 #4, PIN 16 on LS374 #8
PIN 10 <=> PIN 11 on LS374's #1 and #2
PIN 11 <=> PIN 12 on HC14 (same ic), PIN 11 on LS374's #3 and #4
PIN 12 <=> PIN 11 on HC14 (same ic), PIN 11 on LS374's #3 and #4
PIN 13 <=> PIN A47 Edge Top (SDPMPX), also goes to a cap(?) right below ic (right one) with other side being ground
PIN 14 <=> VCC

LS245 (top)
----------
PIN 01 <=> GND
PIN 02 <=> PIN 18 on LS245 (bottom), PIN 18 on HC373 (top and bottom)
PIN 03 <=> PIN 17 on LS245 (bottom), PIN 17 on HC373 (top and bottom)
PIN 04 <=> PIN 16 on LS245 (bottom), PIN 14 on HC373 (top and bottom)
PIN 05 <=> PIN 15 on LS245 (bottom), PIN 13 on HC373 (top and bottom)
PIN 06 <=> PIN 14 on LS245 (bottom), PIN 03 on HC373 (top and bottom)
PIN 07 <=> PIN 13 on LS245 (bottom), PIN 04 on HC373 (top and bottom)
PIN 08 <=> PIN 12 on LS245 (bottom), PIN 07 on HC373 (top and bottom)
PIN 09 <=> PIN 11 on LS245 (bottom), PIN 08 on HC373 (top and bottom)
PIN 10 <=> GND
PIN 11 <=> PIN 14 on 27c322 (all vroms)
PIN 12 <=> PIN 16 on 27c322 (all vroms)
PIN 13 <=> PIN 25 on 27c322 (all vroms)
PIN 14 <=> PIN 23 on 27c322 (all vroms)
PIN 15 <=> PIN 20 on 27c322 (all vroms)
PIN 16 <=> PIN 18 on 27c322 (all vroms)
PIN 17 <=> PIN 27 on 27c322 (all vroms)
PIN 18 <=> PIN 29 on 27c322 (all vroms)
PIN 19 <=> PIN 06 on HC14 (right)
PIN 20 <=> VCC

LS245 (bottom)
----------
PIN 01 <=> VCC
PIN 02 <=> PIN 30 on 27c322 (all vroms)
PIN 03 <=> PIN 28 on 27c322 (all vroms)
PIN 04 <=> PIN 24 on 27c322 (all vroms)
PIN 05 <=> PIN 21 on 27c322 (all vroms)
PIN 06 <=> PIN 24 on 27c322 (all vroms)
PIN 07 <=> PIN 26 on 27c322 (all vroms)
PIN 08 <=> PIN 17 on 27c322 (all vroms)
PIN 09 <=> PIN 15 on 27c322 (all vroms)
PIN 10 <=> GND
PIN 11 <=> PIN 09 on LS245 (top), PIN 08 on HC373 (top and bottom)
PIN 12 <=> PIN 08 on LS245 (top), PIN 07 on HC373 (top and bottom)
PIN 13 <=> PIN 07 on LS245 (top), PIN 04 on HC373 (top and bottom)
PIN 14 <=> PIN 06 on LS245 (top), PIN 03 on HC373 (top and bottom)
PIN 15 <=> PIN 05 on LS245 (top), PIN 13 on HC373 (top and bottom)
PIN 16 <=> PIN 04 on LS245 (top), PIN 14 on HC373 (top and bottom)
PIN 17 <=> PIN 03 on LS245 (top), PIN 17 on HC373 (top and bottom)
PIN 18 <=> PIN 02 on LS245 (top), PIN 18 on HC373 (top and bottom)
PIN 19 <=> PIN 05 on HC15 (right)
PIN 20 <=> VCC

That covers everything you were after?
 
Last edited:
Yes, thank you. That confirms that the LS245 are used to multiplex the 16 bit data from the VROMs to 8 bit. What is a bit weird is that with pin 1 at GND they should be configured for B->A direction, so the bottom LS245 should be configured similar to the top LS245, with the B-port (pin 11 to 18 ) going to the VROMs.

Also interesting the capacitor at SDRMPX and SDPMPX. Maybe to introduce a small delay?

Some data lines don't match up between the latches and the EPROMs - maybe some intentional scrambling?

I'll need to redraw everything cleanly as a schematic...
 
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By the way, I would love to see a CHA board with component and solder side flipped. That would mean you could put sockets on it. Naturally, you couldn't fit it in a normal cart shell anymore and it would likely only work with top slot motherboards, but I wouldn't mind.

You could sandwich the boards like bodgit did with the PGM boards here:

https://www.arcade-projects.com/thr...and-troubleshooting.10015/page-15#post-302061
 
Fluffy said:
Yes, thank you. That confirms that the LS245 are used to multiplex the 16 bit data from the VROMs to 8 bit. What is a bit weird is that with pin 1 at GND they should be configured for B->A direction, so the bottom LS245 should be configured similar to the top LS245, with the B-port (pin 11 to 18 ) going to the VROMs.
Click to expand...

I double checked, you are right. Pin 1 on top 245 is GND and bottom is VCC
 
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