Making a 82S137 PROM from a 28 Pin EPROM (EDITED 17-May-2024) (And also 82S129, 16 pin chips, same idea)
By Dezbaz Orig: 17-June-2021, Perform at your own risk.
This will work on a 28 Pin EPROM
IE: I used a M27C256, but it will also work on a 64, 128, or 512KB EPROM
I asked a question on a KLOV thread initially HERE
Since then a lot of progress has been made.
1. Reading a 82S137 PROM (Or the 16 Pin for 82S129)
Get a 18to28 pin Adapter from our store (Or the 16 Pin for 82S129)
Solder a 18 Pin Dual Wipe IC socket, check it's the right way in.
Make sure all pins are soldered, and no 2 pins are bridged
Use a light and magnifier to be sure
Use the Breakable 2.54mm header and cut 2 lots of 14
Solder both sets of 14. These will go into the EPROM burner/Programmer
Connect the burner to your PC
Open the programmer up, and let it initialize.
Ensure the adapter and chip are both facing the right way
Select M27C256 as your chip
Hit "READ"
Select Buffer, to see data. Copy all the hex code by clicking on it once (Control A will now Select ALL)
Download & Open this Spreadsheet to compare with MAME file (Right click link & select "open in new tab")
PASTE the data in the first spot under "READ from PROM in Burner"
Copy the MAME equivalent file and paste the file somewhere convenient
In my case I had the 136021.111 Star Wars file. Rename the file to 136021-111.bin
Read the file in the programmer, by doing this . . .
Open the relocated/ renamed file 136021-111.bin (etc)
Go to buffer, Copy & paste into the spreadsheet column B under "MAME equivalent File"
You will see the word SAME to the right, for the first 64 lines, and the remaining rows from 65 to 2048 will be FF
You can regard that as a PASS. The file is correct compared to MAME
Now 2048/64 is 32. Reading the 82S137 PROM on the burner automatically generated duplicates 31 more times (32 in total)
But the file opened from MAME did not.
So in conclusion, if you want to read a 82S137 PROM, compare the first 64 lines using the spreadsheet. (Or 16 Pin)
If you want to copy a PROM or Burn a PROM from MAME, that's different
2. Copying a known good 82S137 PROM using a M27C256 EPROM (Or 16 Pin)
Get a 18to28 pin Adapter (Or 16 Pin)
Make up an adapter with 2 x rows of 9 breakable headers. Solder them in first
Solder on a 28 Pin dual wipe socket (the correct way)
Open the programmer up, and let it initialize. (I am using a GQ-4X with external 9V DC Supply)
Insert the other type of 28 Pin adapter (The one described in #1 above) and the known good PROM into the programmer
Ensure the adapter and chip are both facing the right way
Select M27C256 as your chip if you are using a blank M27C256 for your newly copied PROM
Hit "READ"
The programmer should duplicate the hex data 32 times till the end for a 256K IC. If using different KB ICs the amount will be double or half that etc
Remove the 28 Pin adapter and the known good PROM from the burner
Insert the M27C256 IC in the burner
Select Blank Check to ensure the chip is blank (Switch back to message log tab if you are still on the buffer tab)
If it's not blank, repeat the prev step until you have a blank one
If new chip is blank, hit "WRITE" (I have also selected double write, and verify, but it works fine without these boxes checked)
Manually verify a few times to make sure data is the same.
Remove your IC
Stick the newly burned IC into the Adapter you made here in #2
Test it in the game
3. Burning a PROM from MAME (Including the duplication procedure)
Get a 18to28 pin Adapter (Or 16 Pin)
Find the file you want to make a PROM from.
Copy it and paste it to a convenient location on your PC (I suggest a folder easily typed & on the C drive or E drive as the case may be such as C:\PROMS)
Rename it as described above IE: rename 136021.111 to 136021-111.bin etc
Go to Windows Start Button, bottom left of your PC, click it
Type in "cmd", then click on cmd.exe for DOS Prompt
When in DOS, change directory to get to your file
My DOS prompt starts at C:\Users\Dezbaz
Type in cd.. (CD double dot, to go up one level)
Do it again till you see C:\
Then type dir (Directory) and hit enter
You will see your PROMS folder there in the list
type cd PROMS (None of this is case sensitive)
Your file 136021-111.bin etc should be in the same folder from before
Open up this notepad text file (Right click link & select "open in new tab")
Copy the line "copy /b 136021-111.bin + 136021-111.bin 136021-111.binDoubled.bin" (use your file name in place of mine etc)
Follow all the instructions in the txt file to match the size of your EPROM KB size
Open the programmer up, and let it initialize.
Select M27C256 as your chip if you are using a blank M27C256 (Or whatever you're using)
Insert the blank IC chip into the programmer, correct way in
Open the enlarged file from the PROMS folder
Remember:
a 64K chip needs 8x the MAME file data (x2, x2, x2)
a 128K chip needs 16x the MAME file data (x2, x2, x2, x2)
a 256K chip needs 32x the MAME file data (x2, x2, x2, x2, x2)
a 512K chip needs 64x the MAME file data (x2, x2, x2, x2, x2, x2)
Blank Check the new EPROM, and if successful . . .
Hit Write
Verify a few times
Insert the new EPROM onto the 18 to 28 PROM adapter and test in the game PCB (Or 16 Pin)
Thanks for reading
Contact the Author of this mod: amazingarcading@gmail.com