My second A3000 MoBo - PROBLEM LOCATED!

A few weeks ago, I publicly declared I was about to trash my old A3000. Turns out it had a problem with its VGA connector and its now fixed.

However, I was graciously donated another A3000 MoBo. It gave me a green screen and through some investigation I was able to locate the exact source of the problem.

Turns out chips 390526-02 and 390527-02 were busted (U202 and U203 on the board). These are small PAL16L8 20 pin DIP chips which according to this web page (http://amiga.serveftp.net/A3000_HardwareGuide/heat-u202.html) could be replaced with more modern GAL chips that cost (cough cough) 1.40$ each and don't have the overheating problem that busted the PALs in the first place.

And it so happens that I have access to the necessary equipment to program that kind of chips. However, I do not have the JEDEC files that tells what configuration to program in them.

Can anyone help?

[adolescent]

Is this what you're looking for?  

http://www.thule.no/haynie/systems/amiga3k/pals/

I replaced my U202/U203 PALs back in the early 90s but I got them from AmiTrix (something like $20 for the pair so I can't complain...).

adolescent wrote:
Is this what you're looking for?

I would have to say yes. However, of all the files in there, only one is a JEDEC file I can actually use and that's the one for U714.

Any idea how I could convert these .pld files to .JED format ?

[alexh]

PLD are the source files, you need something like PALASM

http://www.brouhaha.com/~eric/retrocomputing/mmi/palasm/

[MastaTabs]

These files are written in CUPL. So you need a cupl translator.

[MastaTabs]

I have compiled the files for ATMEL 16v8 GALs.

Maybe it will work for Lattice ones too.

u202
u203

MastaTabs wrote:
I have compiled the files for ATMEL 16v8 GALs.

Maybe it will work for Lattice ones too.

u202
u203

Haaaaaa! GREAT!

Thanks man!

Just a quick question:

When I select GAL16V8 in my programming software, I get 2194 fuses and that matches the number of fuses addressed in your files.

However, the original Amiga 3000 PLDs are PAL16L8 chips. That being said, it is clear that GAL16V8 can be programmed to behave as many different types of PAL. (16RP4, 16RP6, 10H8, 16P8, 16R8, etc..)

When I select "GAL16V8 as PAL16L8" in my programming software, the device is shown as having 2048 fuses. That is less than the number of fuses your files addresses.

Therefore, I assume your files include the necessary information to tell the GAL16V8 to behave as a PAL16L8.

Please correct me if I am wrong.

[Jeff]

This information should be added to a FAQ when you are done, good work! Let us know how you make out.

Jeff

[alexh]

MastaTabs wrote:
u202
u203

For those people too thick to work out the typo u203 :-)

Jeff wrote:
This information should be added to a FAQ when you are done, good work! Let us know how you make out.

Jeff

I sure will!

I found GAL16V8 chips at 1.18$ each... just ordered a dozen of them...

[MastaTabs]

thanks alex

I've corrected it in my original post too.
 :-)

[MastaTabs]

eslapion wrote:
Just a quick question:

When I select GAL16V8 in my programming software, I get 2194 fuses and that matches the number of fuses addressed in your files.

However, the original Amiga 3000 PLDs are PAL16L8 chips. That being said, it is clear that GAL16V8 can be programmed to behave as many different types of PAL. (16RP4, 16RP6, 10H8, 16P8, 16R8, etc..)

When I select "GAL16V8 as PAL16L8" in my programming software, the device is shown as having 2048 fuses. That is less than the number of fuses your files addresses.

Therefore, I assume your files include the necessary information to tell the GAL16V8 to behave as a PAL16L8.

Please correct me if I am wrong.

I have translated the files for a GAL16V8.
PALs and GALs have a different architecture in which the GALs fuses can be used more efficently.

I would try and programm them as 'normal' GAL16V8. Otherwise the binary code might not match the wanted behaviour.

MastaTabs wrote:
I would try and programm them as 'normal' GAL16V8. Otherwise the binary code might not match the wanted behaviour.

Thanks and BTW... IT WORKS!!! YESSSSSSSSSS!

Can you make .jed files for U714 and U701 too?

Added edit:
=========================================================
I was able to convert Dave Haynie's jedec file for U714 in PAL16L8 format to GAL16V8 format using PALtoGAL.

The resulting file works just fine. I am now missing U701 only.

U202, U203 and U714 all worked just fine using programmed GAL16V8 chips in my A3000.