exxos's Atari, Amiga & retro forum

exxos wrote: 23 Aug 2021 13:50 If you can read the ROM then just post the first few lines of hex codes from it..

00000000 2E 60 04 01 FC 00 30 00 FC 00 00 00 00 00 1C 61 FC 00 30 00 FE 00 4E 82 06 04 89 19 0D 00 86 12 00 00 8C 37
00000024 00 00 7D 0E 00 00 22 56 00 00 00 00 FC 46 00 27 70 4E CD 9B B9 0C 52 FA 5F 23 FA 00 00 00 0A 66 FA 4D 08 00
00000048 F9 4E FA 00 04 00 FA 4D 06 00 00 60 16 06 06 66 6D 1B 24 04 01 80 AD 0C 41 31 26 59 26 04 18 66 2D 20 2A 04
0000006C 2D 4A 2A 04 0E 66 00 08 00 00 08 66 40 20 FA 4D E2 FF D0 4E CD 9B ED 41 00 88 BC 10 07 00 7C 11 C0 00 02 00
00000090 BC 10 0E 00 7C 11 07 00 02 00 3A 08 00 00 7F FF 0E 67 FA 4D 06 00 00 60 1A 0D 7C 1B 02 00 0A 82 ED 43 40 82

That's byte swapped. However, it's more likely a setting in how you read it out rather than an issue with the TOS image on the chip - I hope. It looks like a perfectly fine TOS 1.04.

(I'm sending zChris my 1.02/1.04 dualtos chip anyway)

/Troed

zChris wrote: 23 Aug 2021 14:34 00000000 2E 60 04 01 FC 00 30 00 FC 00 00 00 00 00 1C 61 FC 00 30 00 FE 00 4E 82 06 04 89 19 0D 00 86 12 00 00 8C 37
00000024 00 00 7D 0E 00 00 22 56 00 00 00 00 FC 46 00 27 70 4E CD 9B B9 0C 52 FA 5F 23 FA 00 00 00 0A 66 FA 4D 08 00
00000048 F9 4E FA 00 04 00 FA 4D 06 00 00 60 16 06 06 66 6D 1B 24 04 01 80 AD 0C 41 31 26 59 26 04 18 66 2D 20 2A 04
0000006C 2D 4A 2A 04 0E 66 00 08 00 00 08 66 40 20 FA 4D E2 FF D0 4E CD 9B ED 41 00 88 BC 10 07 00 7C 11 C0 00 02 00
00000090 BC 10 0E 00 7C 11 07 00 02 00 3A 08 00 00 7F FF 0E 67 FA 4D 06 00 00 60 1A 0D 7C 1B 02 00 0A 82 ED 43 40 82

2E = 101110
60 = 1100000

So ROM seems OK. So you likely have a bad address line from the CPU to ROM. Also note the ROM jumper must be closed to select bank 0 .

Like I said before, you need to hardwire without CPU, A1-16,UDS,LDS,AS to gnd. Then run your scope around the ROM IC legs themselves see which address line is not at gnd level.

exxos wrote: 23 Aug 2021 15:03

zChris wrote: 23 Aug 2021 14:34 00000000 2E 60 04 01 FC 00 30 00 FC 00 00 00 00 00 1C 61 FC 00 30 00 FE 00 4E 82 06 04 89 19 0D 00 86 12 00 00 8C 37
00000024 00 00 7D 0E 00 00 22 56 00 00 00 00 FC 46 00 27 70 4E CD 9B B9 0C 52 FA 5F 23 FA 00 00 00 0A 66 FA 4D 08 00
00000048 F9 4E FA 00 04 00 FA 4D 06 00 00 60 16 06 06 66 6D 1B 24 04 01 80 AD 0C 41 31 26 59 26 04 18 66 2D 20 2A 04
0000006C 2D 4A 2A 04 0E 66 00 08 00 00 08 66 40 20 FA 4D E2 FF D0 4E CD 9B ED 41 00 88 BC 10 07 00 7C 11 C0 00 02 00
00000090 BC 10 0E 00 7C 11 07 00 02 00 3A 08 00 00 7F FF 0E 67 FA 4D 06 00 00 60 1A 0D 7C 1B 02 00 0A 82 ED 43 40 82

2E = 101110
60 = 1100000

So ROM seems OK. So you likely have a bad address line from the CPU to ROM. Also note the ROM jumper must be closed to select bank 0 .

Like I said before, you need to hardwire without CPU, A1-16,UDS,LDS,AS to gnd. Then run your scope around the ROM IC legs themselves see which address line is not at gnd level.

So i ground the ones you mention and then measure between the pins a on the ROM IC and ground when the power is on, correct? Have to watch out for VCC i guess so i don't short circuit it?

/zChris

zChris wrote: 23 Aug 2021 17:37 So i ground the ones you mention and then measure between the pins a on the ROM IC and ground when the power is on, correct? Have to watch out for VCC i guess so i don't short circuit it?

Yes & yes.

Seems like we did it! It has been up and running GemBench during the night and it is still running. Thanks to everyone that have been involved :)

What i did was to solder the a12 fix instead of that temporary one and bend out the pins in the IC socket. So im cautiuosly optimistic, we'll see how well it will handle being moved :)

:bravo: :girldance: :girldance:

Well done @zChris, I knew you'd get there in the end.

:cheer: :cheer: :cheer: :cheer:

Well done sir!!

:girldance: :girldance: :girldance:

Great news! Always nice to hear once the patient is better

:thumbup: