#A3640 on A3000
5 messages in this thread
IDI Tech-
I recently had the very same problem. Drove me nuts.
I installed an A3640 in my stock 16mhz A3000 which caused the system
to either ignore my hardrive attached to the 3000's SCSI port, or sometimes it
would recognize it during execution of startup-sequence and later crash with
"Disk Checksum error on Block xxxx", or some such gobbilty goop. Somehow,
I isolated the problem to be a conflict between the A3000's Static Column
Zips
and the A3640 – This combo freaks out the SCSI port.
I discovered this by taking a PAGE mode zip off of my Retina ZIII Display Board
and replacing the static column mode ZIP in the first Zip socket (U852, I
think)
in the A3000.
This forces the A3000 FastRam to function in Page Mode , which slows things
down just enought for the A3640-SCSI conflict to go away. I was told by someone
much more knowledgeable about this that the reason the Static Column mode
caused problems and Page mode did not is because the 68040 processor does
not use "BURST" memory mode if page mode Zips are used. He said that static
column mode zips would probably work if "Burst" mode were disabled with
a startup-sequence command. I did not attempt such considering that I got the
damn thing working and thought I should leave well enough alone.
Oh, and of course, there are several jumpers on the A3000 motherboard you need
to set to 25mhz. I don't recall wich all numbers they were, Check your A3000
Manual
In Appendix E-1 the A3000 Schematics identify jumpers and corresponding
settings
for either 16mhz or 25mhz clock speed.
(BTW, every Amiga hardware expert I consulted with said the A3640 would only
work with
the A3000T Tower . Mine now works fine and has for 4 months. )
Good Luck. Would like to here if this works for you too.
-Charlie McCann
70107,1506
I have a rev 3.1 A3640 working on my desktop A3000 with Static Column Zips, so
I'll back you up on all those techs being wrong. I think that the new rev does
away with the Zip problem, but it also becomes fussy with DMAC, Ramsey, and
Buster. I can't install the new rev-11 Buster without bus cards becoming
unrecognized, however the older rev-7 that I have works just fine. Good thing
I don't have any full Zorro-3 boards yet…
Regards, Keith.
What do you mean, there's a reason not to upgrade the Buster in 3ks?
Paul (aka Mr. Zombie)
I'm saying that I've found an incompatability problem with my rev 3.1 A3640
accelerator and a rev-11 Buster. By switching back to my older rev-07 Buster,
the bus cards became recognizeable once again. It's a good thing that I really
don't have any cards at this time that take full advantage of the new rev-11
chip. I've come to believe that the higher speed of the A3640 requires you to
also update the Ramsey and DMAC chips if you want to use the new rev-11 Buster.
Unfortunately, I can't prove this theory due to the fact that there seem to be
no more "new" Ramsey and DMAC chips left. I'm posting this just to let you
know of a problem you may encounter.
Regards, Keith.