MK2 4Mb to 8Mb roms help

[aha2940]

Hi

I currently have an old MK2 board with all 4Mb roms. It is temperamental and it does work whenever it feels to. I want to convert it to use 8Mb roms following this procedure: http://forums.arcade-museum.com/showthread.php?t=336539
I already checked, and have everything needed for the conversion, except for the 8Mb PAL chip. I have never programmed one, and do not know where to get its information, can anybody shed any light on this? or maybe even sell me the correct pre-programmed chip?

Thanks!

Edit: So, I found a file that it says it's the one needed for programming this PAL: http://www.jammarcade.net/pal-dumps/ however all I get is a text file with a .JED extension that seems to contain a binary matrix inside...is that the correct file?

 

[PascalP]

Maybe this helps you out?

 

[aha2940]

Maybe this helps you out?

Thanks for the info, it's nice seeing the conversion process working, however the part where I need detail is exactly what the video does not cover: how to burn the PAL/GAL chip to make the 8Mb version work...

 

[yavuzg]

Have you checked the PLD Archive site? (http://www.jammarcade.net/pal-dumps/)

I never did the conversion myself (I already have the 8Mb version) but when I search their database they seem to have the necessary PAL dump you're looking for...

 

[aha2940]

Have you checked the PLD Archive site? (http://www.jammarcade.net/pal-dumps/)

I never did the conversion myself (I already have the 8Mb version) but when I search their database they seem to have the necessary PAL dump you're looking for...

Hey, thanks for the help. Yes, I did find the file in that web page, however I do not know how to use it. I am used to burning roms (which are binary files) to EPROMs, but this seems to be a text file with some human-readable instructions and the binary matrix inside. Is that the correct file? how to write it to a GAL chip? can I take a used GAL chip and rewrite it?

Thanks!!

 

[yavuzg]

I use TL-866 programmer to program GAL chips. Generally, on arcade boards you see "PAL" chips, which are not re-writable (except the "PAL CE" versions). GAL chips are re-writable. So you buy the appropriate size GAL equivalent chip (i.e. in your case GAL16V8 for the A-1774 and program it with the JED file you downloaded just as you program your EPROMs.

You have to check the supported device list of your burner/programmer. If it supports programming GALs then you are good to go. If not, I recommend the cheap TL-866 from aliexpress...

 

[aha2940]

I use TL-866 programmer to program GAL chips. Generally, on arcade boards you see "PAL" chips, which are not re-writable (except the "PAL CE" versions). GAL chips are re-writable. So you buy the appropriate size GAL equivalent chip (i.e. in your case GAL16V8 for the A-1774 and program it with the JED file you downloaded just as you program your EPROMs.

You have to check the supported device list of your burner/programmer. If it supports programming GALs then you are good to go. If not, I recommend the cheap TL-866 from aliexpress...

Thanks for the detailed instructions, very useful. I think my programmer (TOP3000) can manage the GAL chips, but only a test will tell for sure. I think I'll get the required EPROMs and the GAL to try to convert this MK2 board.

Thanks!!