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Fluffy

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People who follow the PGM Conversion thread may know that I'm working on replacement PCBs for IGS Polygame Master, so people can make cartridge versions of the three CAVE shooters without sacrificing donor carts for the PCBs.

My current version has a few flaws, a major one being that I messed up the address decoder for the sample ROM:
IMG_20190223_104146.jpg


Features:
- 27c322 EPROMS - so no messing around with voltage regulators or running chips out of spec
- should work for all three CAVE titles
- only uses through-hole components
- ENIG gold plating

Problems:
- footprints for capacitors are very narrow (fixed in version 1.1)
- the board fit into the cartridge shell is a bit tight (fixed in version 1.1)
- the logic chips are a bit close to the pcb edge (fixed in version 1.1)
- the two address decoder pins marked above are swapped. So when installing the 74LS139 you'll need to lift pins and connect them to the correct pad with wires... (fixed in version 1.1)

Limitations:
- this is only a replacement for the graphics board so far. For a full conversion we'll need a program board as well, and I need a few of the remaining mysteries solved before I'm comfortable ordering PCBs.
- this is NOT a multi-cart, and my focus are the CAVE games. (Other games may need more ROM space, and a different sample ROM decoding logic.) If you're after a proper multi-ROM it'll be worth waiting for whatever Darksoft will cook up.
- the 27c322 EPROMs are obsolete, so you'll probably have to get recycled ones from eBay.
- I installed the chips into sockets in the image above, but the board will NOT fit into the cartridge this way.
- the board is not really usable for mass production, you'll probably want larger ROMs which are only available as SMD components. And installing recycled EPROMS with crooked legs is very fiddly.

I'll get new boards made when I finish the program board, so I want to use this chance to get some feedback. I'm willing to send a few of the board away for people to test, providing:
- they pay for postage
- they make a small donation to charity
- they should already have a CAVE conversion to compare against, or be prepared to convert a program board (Any PGM Conversion info out there? for compatible program boards.) It should be enough to swap the EPROM with the program, then you'll just have to play with corrupted background graphics...
- they are able to do the soldering and EPROM programming (and possible debugging) themselves. I can't do support, as I hardly know what I'm doing myself...
 
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I can't do any of the above, so I'm not in as a tester, but this is awesome and I'll buy some when you are all set!

I also have a real Espgaluda in case you need to compare anything1
 
- this is NOT a multi-cart, and my focus are the CAVE games. (Other games may need more ROM space, and a different sample ROM decoding logic.) If you're after a proper multi-ROM it'll be worth waiting for whatever Darksoft will cook up.
It's still a very good base for a multi.
Basically what I do is I try to run the biggest known game for a system from a proto board then I now I should be able to run all other games (give or take a different banking method).
 
It's still a very good base for a multi.Basically what I do is I try to run the biggest known game for a system from a proto board then I now I should be able to run all other games (give or take a different banking method).
The decoders should be enough to address twice the number of ROMs (8 A-ROMs and 4 B-ROMs),and the major difference between games seems to be the base address of the sample ROM. So in theory you could get the next larger size by piggy-packing a second ROM on each footprint and using the remaining select pins available, and hack the decoding of the M-ROM to whatever you need (0x400000 or 0x800000).
It may be much easier to just use a large single ROM for each data type, and a GAL to decode the M-ROM. You'll have to move to SMD parts and 3V devices for that, though, and at the moment I don't want to do that.
Of course, if you or Darksoft want to use this as a basis of a Multi ROM your are welcome to do so!
 
I'm in! :) I'm really looking forward to see were it goes... :)

FYI ST was going to do a 64mbit eprom in DIP format. The "M27C642". There was also a TSOP version as well....

Intel also build some sop 5V 64mbit flash chips.....

D.
 
@Fluffy

I would help you w/ testing, but no spare 27C322 at this moment and very little spare time for the next 2 weeks.
I do have DDPDOJ cart conversion and a PGM to play around with.
Let me know if i can be of any help, i have all the tools required and some 68K knowledge ;)
 
I'm in! :) I'm really looking forward to see were it goes... :)

FYI ST was going to do a 64mbit eprom in DIP format. The "M27C642". There was also a TSOP version as well....

Intel also build some sop 5V 64mbit flash chips.....

D.
Two actually, 27C642 as 16 bit only and 27C640 as 8/16bit.
 
The Lydz board is using three ROM chips:
Any PGM Conversion info out there?

A and B ROM are 16 bit wide, the M ROM is 8 bit wide. I am using a multiplexer on my board for the M-ROM because I couldn't find an appropriately sized 8-bit wide ROM. It looks like a lot of the larger types are obsolete nowadays...
 
Build instructions:

Code:
Instructions:
------------

You need:
7x 27c322 EPROMs
2x 74LS257
1x 74LS139
1x 74LS138

11x 0.1uF capacitor
2x 10uF capacitor (electrolytic, 16V, though anything higher should work as well. The capacitance doesn't need to match exactly, either.)

Soldering:
The positions for the 74LS logic chips are marked on the PCB. The current board layout has an error, and
pin 2 and 3 of U10 (74LS139) need to be swapped. If you use sockets you won't be able to fit the board into the cartridge shell.

ROM files:
You can take the ROM files used for Mame, as they are unencrypted and uncompressed. You'll need to split 8MB ROM images into two 4MB files to fit 
into the EPROMs.
https://github.com/mamedev/mame/blob/6d4ba81467d94a838fb132aa9a0c5bdbffc6fd6d/src/mame/drivers/pgm.cpp#L4482
The graphics board takes the "sprcol", "sprmask" and "ics" files. Position "B1"-"B2" take the sprmask ROMs, "A1"-"A4" take the sprcol ROMs, and "M1" takes the 
ics ROM.
I found it much easier to fit new sockets into the board and then install EPROMs into the sockets, than trying to insert EPROMs with bent pins.

Installation:
Double check that you don't have a short circuit, and that all chips are oriented correctly. The graphics board is the lower board, and the 
components need to face down. Double-check against an original cartridge before switching on.
Pictures (from the other thread):
IMG_20190131_000539.jpg

This is how the soldered board should look like.

IMG_20190131_000438.jpg

This is how the program ROM for DDPDOJ is installed in my KOVSH board. Notice the arrangement of boards and which directions they are facing. I put a pencil eraser between the board to prevent short circuits.

IMG_20190209_002729.jpg

This is a decryped version of the program ROM for DDPDOJ installed in my KOV2 board.
 
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What voltage for the capacitors?

Going to try and get everything ordered tonight so I can provide feedback when it arrives :)
 
in theory you could get the next larger size by piggy-packing a second ROM on each footprint and using the remaining select pins available, and hack the decoding of the M-ROM to whatever you need (0x400000 or 0x800000).
you could also consider putting the footprint on the PCB in support of larger SMD ROMS in addition to the footprint for a 3.3V voltage converter. that way a single PCB could be used for either and still fit inside a cart housing.
 
What voltage for the capacitors?

Going to try and get everything ordered tonight so I can provide feedback when it arrives :)
The 2 electrolytic Caps are on the 5V line. So 16V caps are common to buy. You can get 10V caps.. but there not as common. So grab 16V ones.

The ceramic Caps normal start at 25-50V... So thats also fine.

D.
 
you could also consider putting the footprint on the PCB in support of larger SMD ROMS in addition to the footprint for a 3.3V voltage converter. that way a single PCB could be used for either and still fit inside a cart housing.
I considered it originally, but the horizontal routing between footprints gets in the way. It'll be significantly easier to make a separate PCB.

(I'll update the instructions about the capacitors.)
 
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Hey all,

I have started on another related PGM project. I'm trying to scan every PCBs from all the games for the PGM. Will take a while... I'm doing them at 200dpi.. which seams to work well.... You can zoom into them and read chips and follow pcb tracks around...
I'm new to Word Press.. but it just needs to be a "basic" web site....

D.
 
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