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Confirming no compatibility with A570 CD-ROM

Posted: Sun May 26, 2019 1:19 pm
by dalek
Not that I expected it, but I was hopeful that since the TF534 put it's RAM in Z3 space that maybe the A570 would work.

Alas black screen on startup - at least with v2.30 of the A570 ROM. It is widely known the A570 isn't compatible with accelerators. Does anyone know what it does at startup that is so funky? I know it has it's own ROM that augments/runs before kickstart. But I wonder what it does there that rules out different CPUs. I guess one day I could look at disassembling that ROM.

Also of note:
  • I've tried with both Cache and MMU Disable jumpers closed.
  • I've tried DiagROM - same black screen - DiagROM never even starts with the TF534 + A570.
  • The original 68000 + A570 + DiagROM works fine.
Anyway, just documenting state of play, wondering if a solution is even possible.

Re: Confirming no compatibility with A570 CD-ROM

Posted: Sun May 26, 2019 1:28 pm
by terriblefire
I managed to get the CDTV to boot with a TF534 (without the roms) so no idea whats happening.

Re: Confirming no compatibility with A570 CD-ROM

Posted: Sun May 26, 2019 6:52 pm
by 8 Bit Dreams
terriblefire wrote: Sun May 26, 2019 1:28 pm I managed to get the CDTV to boot with a TF534 (without the roms) so no idea whats happening.
Yeah.. Without Extended roms (Jumper JP15 removed) CDTV acts as standard A500. the problem is that CDTV does ALWAYS a DMAC autoconfig, hence ide will not work untill You have an idea how to override it

Re: Confirming no compatibility with A570 CD-ROM

Posted: Sun May 26, 2019 6:58 pm
by terriblefire
I'll really take a good look at each machine with the TF5xx series once the 360 is working.

Re: Confirming no compatibility with A570 CD-ROM

Posted: Sun May 26, 2019 7:02 pm
by 8 Bit Dreams
that would be great, Stephen..
In fact, CDTV - is the only Amiga without any modern accelerator... any other model is covered, just not CDTV...

Re: Confirming no compatibility with A570 CD-ROM

Posted: Sun May 26, 2019 7:03 pm
by terriblefire
8 Bit Dreams wrote: Sun May 26, 2019 7:02 pm that would be great, Stephen..
In fact, CDTV - is the only Amiga without any modern accelerator... any other model is covered, just not CDTV...
The CDTV is an awful machine though. I really hate it.

Plus mine has a dead U75.

Re: Confirming no compatibility with A570 CD-ROM

Posted: Tue Jun 11, 2019 3:48 am
by dalek
Found some useful info here. In particular, see the descriptions of how /CSS and /CFGIN are used.

So $E900000 is where the CDTV/A570 DMAC essentially hardcodes itself but also where the SPI port on the TF534 is hardcoded. When I get a chance I'll do a test by disabling the SPI port in the firmware and see if it gets any further.

Also could be issues with CFGOUT not being connected, meaning we might need two separate runs of autoconfig...

And some unrelated info as to how the CDTV ROM is activated here.

Not asking anyone to fix it, just thinking out loud and trying to document everything on the subject in the one place!

Re: Confirming no compatibility with A570 CD-ROM

Posted: Wed Oct 09, 2019 1:01 pm
by GadgetUK164
dalek wrote: Tue Jun 11, 2019 3:48 am Found some useful info here. In particular, see the descriptions of how /CSS and /CFGIN are used.

So $E900000 is where the CDTV/A570 DMAC essentially hardcodes itself but also where the SPI port on the TF534 is hardcoded. When I get a chance I'll do a test by disabling the SPI port in the firmware and see if it gets any further.

Also could be issues with CFGOUT not being connected, meaning we might need two separate runs of autoconfig...

And some unrelated info as to how the CDTV ROM is activated here.

Not asking anyone to fix it, just thinking out loud and trying to document everything on the subject in the one place!
Let me know how you get on with that! I might try the same thing myself - I might not need to yet, not sure. I've got an A2091 working (regards RAM) with the 534, but that has the same (I think) DMAC chip on there, just not sure where its base address is yet.

Re: Confirming no compatibility with A570 CD-ROM

Posted: Thu Oct 10, 2019 12:08 pm
by dalek
Cool - yeah it's on my todo list but life has got in the way of progress at the moment. See also here: https://www.exxosforum.co.uk/forum/viewt ... =65&t=2036

Plan is to rebuild the CDTV/A570 ROM with a cdtv.device that only allocmem's from MEMF_CHIP RAM instead of MEMF_PUBLIC. So rebuild cdtv.device and stuff it back in there.

Re: Confirming no compatibility with A570 CD-ROM

Posted: Fri Oct 11, 2019 9:52 am
by GadgetUK164
I've got my own (different) problem with the A2091 - but that might related to the CD ROM drive or something else entirely. Whilst it uses the same DMAC chip, it seems autoconfig places it in a different location that doesnt seem to clash with the SPI.

I've worked out that if autoconfig is enabled, and the CD drive not connected, it will boot. I can see the devices on different addresses and everything functions normally. If I connect the CD drive up it is scanning the SCSI chain on boot, and starts to read the drive (assumed trying to boot from it or something as it is spinning up with the LED on). And I get no further than that. My guess is the autoconfig ROM and the driver it provides is my issue.

I will keep digging - thinking of trying the v7 ROM for the A2091, and I've also ordered a replacement WDC controller (-08 rev) to see if that solves my particular issue. What I do know is when the drive isn't connected, everything boots normally and in SysInfo I see the 2nd.scsi.device there, which leads me to believe the autoconfig has worked, driver available etc, and that the root of my issue is the ROM trying to boot from the CD, or sitting there looking for a HDD maybe. I did wonder if I could extract that 2nd.scsi.device and install it in devs, disable autoboot ROM and try that way - that might work?!? No idea, out of my depth atm lol.

EDIT: Just flashing v7 BIOS for the A2091 - will try that next and report back.