The strictly Amiga only thread. No socializing!

[TheBilgeRat]

Wondering this myself.  I wanna go a Mechy Adapter route, but I'm still running stock 68000 in my 2000 with a 2091 with rev4 WD chip and 6.6 roms.  I dunno if my Rev4 chip and barebones is up to the task.

BUT I gotta think anything is better than my 40MB SCSI drive from 1990...

[TheBilgeRat]

90KB/sec is very slow. I've got a GVP HC+8 card with a Guru ROM, connected to Mechy's native SCSI CF card reader on my A2000. I'm using a Transcend 16GB 133x CF card. I'm getting ~1.5MB/sec transfer rates on it regardless if I'm in 68000 or 68030 mode.

I had to disable synchronous transfers on the CF reader otherwise it would randomly lock up when copying large amounts of data. Disabling synchronous transfers didn't seem to have an impact on performance though.

The GVP card does SCSI DMA directly into it's onboard ram, I'm not sure if the A2091 does the same.

If you can, get a Guru rom for your A2091, it made a huge difference to my GVP HC+8 in terms of stability and performance. Unfortunately the adapters that the Guru rom plugs into are difficult to come by. The rom image itself is available on Ralph Babel's hompage http://babel.de/amiga.html but it won't work without the adapter.

Sorry I can't help you more..

Hard to get a picture of just the adapter.  I wonder if its just mapping one chipsize to another 1 to 1, or if there is some logic on it...

[TheBilgeRat]

The adapter has a PAL to do some sort of address decoding as the GVP/A2091 card only has enough address lines for a 16KB ROM (27C128). The Guru ROM is a 32KB chip (27C256). I have tried to copy the PAL but naturally it  has the copy bit enabled so I couldn't copy it.

It is frustrating as the Guru rom is no longer commercially available. I'm always happy to support any hardware vendors such as Jens and Ralph but when they decide to no longer support a device, they should make things like the PAL image available to everyone so that we can at least make the adapters ourselves.

I did not realize that the chip was made by Ralph Babel - there's no chance we'll ever get that adapter array information.

I can get 7.0 ROMs for my card - its the rev 8 WB chip that is the hard one to find.

[TheBilgeRat]

Mechy sells them on his website, not too expensive either, it's the AMD version which is the same as the -08 WD version.

http://a4000t.com/store/index.php?main_page=product_info&products_id=210&zenid=ce58e464a2906f5a92768b7e20cdacd1

Cheers

Sweet!  Thanks a bunch!

[TheBilgeRat]

It's a pleasure!

I'll swap my Guru rom for the regular v4.15 GVP rom and set my A2000 to 68000 mode and do some benchmarks for you. I know it's not exactly the same as your A2091, but it'll at least be an indication of what you can expect.

The main reason I went the CF route is that with all the expansion cards and 7200RPM SCSI drive in my A2000, the A2000 was getting REALLY hot. I could barely touch the HDD. After swapping it for the CF solution, it was running MUCH cooler but it also made my A2000 much faster. Not in terms of raw speed, but workbench operations are much snappier, opening a drawer with lots of games in it is now much quicker.

I'd definitely recommend going the CF route over a normal HDD.

I noticed a huge speedup in my A4000 when I stuck a CF card in it, and just on the motherboard IDE port, which everyone poo-poohs as slow.  Right now I am waiting to redo the caps on the mobo for her, so the 2000 is getting some love, since its recap is and was easily accomplished with just an iron and some solder wick.  There's something to be said for wide open and easily accessible componentry!

[TheBilgeRat]

I have talked to ralph about this at one time, and because places like softhut list them but do not have them,ralph won't release the code because he says it would undercut vendors. I explained that i contacted softhut and they don't have the guru roms but this did no good.

mech

Aren't you an Amiga Vendor?  Do you not qualify as a distributor?

[TheBilgeRat]

Amiga, can of beer, G5 Mac in the background.
What's the point Harry?

Just that he's an OG Finnish Pimp...