exxos's Atari, Amiga & retro forum

JaosnE wrote: 28 Nov 2021 04:05 Very frustrating. I may give up and look for an 040 solution.

Do that. The A2000 isnt supported and even if you get this working as mentioned by Gadget the A2091 is painfully slow in PIO mode. The A2091 cannot DMA into TF memory so it has to do transfers the slow way.

Using an alternative accelerator is your best option.

Once again repeating myself but a little background to why this is pointless to attempt.

Contrary to what the people on EAB say the TF536 does support all the bus arb signals (If it didn't it simply wouldn't work on the Atari ST) and does allow DMA between any 2 devices on the 68000 24 bit bus address/16bit data bus. But the TF 32bit ram is not on that bus and it cannot be accessed by anything off the CPU card. So if your address mask isnt set correctly your driver will attempt to DMA into this memory region... that will not work (because there are 8 address lines missing on the 68000) and it will probably just trash chipram in the process.

Assuming your driver is smart and can fallback to PIO mode then there are ways to get this to work by setting the BufMemType and address mask of your card in the mountlist. The reason people havent got this posted anywhere is that your max speed with this is going to be around 512k/sec... which is useless. Just dont bother.

The TF536 was not designed with this scenario in mind. Its a cheap WHDLoad card for an A500 that happens to run in other machines too.

I realize the A2091 will be slow without DMA, but I would like to get it working to access other SCSI drives.

I've upgraded the 2091 roms to V7. It will boot with the card in now but will not recognize any of the drives.

that's pretty much where i was with mine as well.. card is "working" according to the amiga hardware check at boot.. i gave up and moved on. I'm currently trying to get a zip drive to work. IDEFix97 sees it, but it's not popping up anywhere as a drive when i select it.

As mentioned before.. Have you created a mountlist entry for it with BufMemType=512 ? It will absolutely not work automatically from a gui. It needs to know it cant DMA into the TF ram.

RTFM Amiga Mountlists.

https://wiki.amigaos.net/wiki/AmigaOS_M ... irectories

yea i didn't do that with mine unfortunately. i booted from floppy, but i could see that i would still have needed to modify the floppy like any other wb bootup sequence and include that. i skimmed too much.

JaosnE wrote: 08 Dec 2021 03:48 I realize the A2091 will be slow without DMA, but I would like to get it working to access other SCSI drives.

I've upgraded the 2091 roms to V7. It will boot with the card in now but will not recognize any of the drives.

It's not because you have an overlap (like I did) is it? ie. Two lots of DH0, two lots of DH1 etc.

From what I understand Workbench (or the ROM?) is supposed to append a _1 to them - but I've never seen that happen when using the A2091 and KS3.1. I had to use HDToolBox on the SCSI drives first (without 536 connected), and change them to another prefix - eg. SH0, SH1 etc. Then they should all appear. Note, with the latest firmware I cannot get ZII RAM working alongside the 536 - so I disable it on the A2091. That means it falls back to PIO, but it does work for me that way on 3 different A2000 boards!