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Re: A500 - resurrection or pit of despair?
Posted: 12 Feb 2026 17:18
by 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 :roll:
Re: A500 - resurrection or pit of despair?
Posted: 12 Feb 2026 17:42
by rubber_jonnie
JezC wrote: 12 Feb 2026 17:18
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 :roll:
I just remembered I got one of these for my TL866:
IMG20260212174034.jpg
I didn't end up using it because I used the BooBip ROM emulator instead...
Re: A500 - resurrection or pit of despair?
Posted: 12 Feb 2026 21:12
by JezC
rubber_jonnie wrote: 12 Feb 2026 17:42
JezC wrote: 12 Feb 2026 17:18
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 :roll:
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...
Re: A500 - resurrection or pit of despair?
Posted: 12 Feb 2026 21:16
by rubber_jonnie
JezC wrote: 12 Feb 2026 21:12
rubber_jonnie wrote: 12 Feb 2026 17:42
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...
Re: A500 - resurrection or pit of despair?
Posted: 13 Feb 2026 09:27
by JezC
rubber_jonnie wrote: 12 Feb 2026 21:16
JezC wrote: 12 Feb 2026 21:12
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!
Re: A500 - resurrection or pit of despair?
Posted: 13 Feb 2026 09:41
by rubber_jonnie
JezC wrote: 13 Feb 2026 09:27
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 :)
JezC wrote: 13 Feb 2026 09:27
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.
Re: A500 - resurrection or pit of despair?
Posted: 13 Feb 2026 09:49
by JezC
rubber_jonnie wrote: 13 Feb 2026 09:41
JezC wrote: 13 Feb 2026 09:27
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!
rubber_jonnie wrote: 13 Feb 2026 09:41
JezC wrote: 13 Feb 2026 09:27
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.