A500 - resurrection or pit of despair?

[JezC]

Ok, so the IDE & RAM upgrade board has arrived so I will test that in the Rev 5 A500 soon (I hope).

@rubber_jonnie also kindly included a 27C400 EPROM so that I can program up a DIAGROM to see what the problem with the Rev 6 board is (green screen on boot).

The issue there is that I can't see an option for the specific 27C400 EPROM in the list for my TL866 programmer...

Some research required here I guess

[rubber_jonnie]

Ok, so the IDE & RAM upgrade board has arrived so I will test that in the Rev 5 A500 soon (I hope).

@rubber_jonnie also kindly included a 27C400 EPROM so that I can program up a DIAGROM to see what the problem with the Rev 6 board is (green screen on boot).

The issue there is that I can't see an option for the specific 27C400 EPROM in the list for my TL866 programmer...

Some research required here I guess

I just remembered I got one of these for my TL866:

IMG20260212174034.jpg (190.35 KiB) Viewed 860 times

I didn't end up using it because I used the BooBip ROM emulator instead...

[JezC]

Ok, so the IDE & RAM upgrade board has arrived so I will test that in the Rev 5 A500 soon (I hope).

@rubber_jonnie also kindly included a 27C400 EPROM so that I can program up a DIAGROM to see what the problem with the Rev 6 board is (green screen on boot).

The issue there is that I can't see an option for the specific 27C400 EPROM in the list for my TL866 programmer...

Some research required here I guess

I just remembered I got one of these for my TL866:

I didn't end up using it because I used the BooBip ROM emulator instead...

Ah, thanks for the info. I may look up the details of the PCB and bodge together and equivalent... otherwise I can see it taking a week or so to get one ordered and delivered!

My backup plan is to check on the vintage programmers in the garage and see if they can program this chip...

[rubber_jonnie]

I just remembered I got one of these for my TL866:

I didn't end up using it because I used the BooBip ROM emulator instead...

Ah, thanks for the info. I may look up the details of the PCB and bodge together and equivalent... otherwise I can see it taking a week or so to get one ordered and delivered!

My backup plan is to check on the vintage programmers in the garage and see if they can program this chip...

No worries and good luck!

Sorry I should have thought of it earlier, but the BooBip caught me off guard with it's lovely USBness...

[JezC]

Ah, thanks for the info. I may look up the details of the PCB and bodge together and equivalent... otherwise I can see it taking a week or so to get one ordered and delivered!

My backup plan is to check on the vintage programmers in the garage and see if they can program this chip...

No worries and good luck!

Thanks - I might not get chance to dig into this until later in the weekend as my son is coming back from university today & staying for the weekend, so unlikely to get much time for retro stuff today.

Sorry I should have thought of it earlier, but the BooBip caught me off guard with it's lovely USBness...

No worries - I'd love one of those, shame they're no longer being manufactured!

[rubber_jonnie]

Thanks - I might not get chance to dig into this until later in the weekend as my son is coming back from university today & staying for the weekend, so unlikely to get much time for retro stuff today.

Have a nice weekend with your family

No worries - I'd love one of those, shame they're no longer being manufactured!

Yeah it is, though I think I sen you a link for an alternative, though not particularly cheap if you only have limited use for them.

[JezC]

Thanks - I might not get chance to dig into this until later in the weekend as my son is coming back from university today & staying for the weekend, so unlikely to get much time for retro stuff today.

Have a nice weekend with your family

Thanks!

No worries - I'd love one of those, shame they're no longer being manufactured!

Yeah it is, though I think I sen you a link for an alternative, though not particularly cheap if you only have limited use for them.

Yes, you did...but as you say a bit pricey for a 'single use' but I'll see how the adapter options work out as an alternative.

[JezC]

So, as a general update (and so I can find the info again at some point in the future)...

I ended up using the rev 5 board to get an internal PiStorm adapter & Pi Zero 2W up & running (though I'm not sure that will be the final use for that A500 long-term - that PiStorm adapter is probably going to go into an ST remake board but then if I can repair my other PiStorm adapter...).

A huge shout out to @rubber_jonnie for his helps & support in getting that working via numerous PMs - the guy is a legend!

I picked up an unpopulated working rev 6A board & after moving all the custom chips over form my faulty rev 6A board, that one now boots up OK & can run games etc.

I've still not yet sorted out the fault on the original rev 6A board, but it all counts as progress, especially while I'm still so short of retro hobby time.

What I need to do now is decide if I should have the PiStorm in my rev 5 board & use that RAM + IDE i/f in the rev 6 (with an upgraded ROM - as that board will work with EPROMs without any mods from what I understand)...

I will have a read up and think on that for a while but as always I'd be interested in anybody else's opinion on the pros and cons of which upgrade in which board version - the rev 6a only has the 4x RAM chips fitted at the moment & I think I only currently have the one working 512k upgrade for the trapdoor...

[rubber_jonnie]

A huge shout out to @rubber_jonnie for his helps & support in getting that working via numerous PMs - the guy is a legend!

Happy to help any time, appreciate the shout out

I picked up an unpopulated working rev 6A board & after moving all the custom chips over form my faulty rev 6A board, that one now boots up OK & can run games etc.

Excellent, always good to have multiple machines of the same type that work.

What I need to do now is decide if I should have the PiStorm in my rev 5 board & use that RAM + IDE i/f in the rev 6 (with an upgraded ROM - as that board will work with EPROMs without any mods from what I understand)...

It's good to have choices too

I will have a read up and think on that for a while but as always I'd be interested in anybody else's opinion on the pros and cons of which upgrade in which board version - the rev 6a only has the 4x RAM chips fitted at the moment & I think I only currently have the one working 512k upgrade for the trapdoor...

Plenty of trapdoor updates out there You'll be fine