#A2000 RAM W/Accel Card
13 messages in this thread
I have a friend with a 2000. It has 8 MB fast RAM on an expansion card.
The SCSI controller is on a separate card.
If he adds a CBM 2630 accelerator card with its own local 32-bit memory,
can he still access the 8 MB of fast RAM on the other expansion card in
addition to any fast RAM on the accelerator card?
-J (Wandering around on AutoPilot)
Jay,
The 2630's memory is standard "autoconfig" memory, which means that it
configures into the same memory space used for Zorro-II boards. Your
friend would have to limit his 16-bit fast RAM to 4 megs (assuming 4 megs
on the 2630) – he'd have a total of 8 megs of fast memory available, 4 of
which would be 32 bit.
Hope this helps…
– BobR
bob;
Why does the 16-bit fast RAM have to be limited to 4 megs? I'm curious
about this because I have an 030 board with 8 megs 32-bit memory and a
Microbotics 8-UP with 6 megs of 16-bit memory and the system can only find
13 megs of memory.
Charlie Badalati
APing from W\rselen,Germany
Charlie,
The Zorro-II bus specifications reserve 8 megs of memory space for
autoconfiguration by the addon peripherals. DMA is limited to this 8
megs, as is the addressing capability of the CPU on the motherboard. With
an add-on CPU on the expansion accellerator board taking over the process,
it can address additional memory contained on it's board, but other
peripherals in the system cannot (i.e., it cannot be accessed by the DMA
controller on the motherboard, and therefore cannot be accessed by any
other boards in the system).
Some third-party CPU boards do allow for memory to be added beyond the
reserved autoconfig address space. The standard 2630 does not – it's 4
megs of memory configure into the standard autoconfig space. The
advantage to this is that a DMA harddisk controller can read into/write
from this 32-bit memory directly via DMA access. The dis-advantage is
that this only leaves 4 additional megs of "autoconfig" memory available
to the other boards in the system.
Hope this helps….
– BobR
OK, I recall all of that, but what I can't figure out is how to build the
system I need…
I am using an A2000/2630/2091 for digital audio and MIDI in my studio. I
want LOTS of memory and fast disk access! I have a couple of options that
I can see:
1) buy the DKB memory add-on board for the 2630 and add a bunch of memory
there… disadvantage, as far as I can figure, the 2091 won't see that
memory directly, the processor will have to handle data xfer
2) replace the 2630/2091 with an all-in-one card such as the Vector or one
of GVP's boards. Now the SCSI host adapter has access to any memory on the
cpu card. disadvantages, non-standard ( i.e. scsi_direct may not be
supported) and more expensive!
Any suggestions??
Bill… on Autopilot in Womelsdorf 😉
Bill,
I have no personal experience with the GVP boards, but have heard
"mixed" reviews of them from others. Some folks really like then, others
have reported problems of compatibility. I don't recall the specifics.
I've never heard of the Vector board – is that a European hardware
vendor?
What you say about expanding the 2630's memory with DKB's daughterboard
is true, as far as I know. I've never heard of anyone experiencing any
problems with the board, or with any of DKB's products. I've talked to
Dean Brown a number of times, and have no reservations about recommending
his products – he does good stuff.
Good luck in your quest…
– BobR
Bill:
Pardon me for jumping in here, but for the money you're talking about
spending (for the memory, possible accel update, etc) you might be better
off selling your A2000 and buying an A3000. First off the price of the
base machine has been lowered to MSRP $1499.00, and you might find the
street price even cheaper, I'm not sure as I havn't been shopping for one
lately. Next, the A3000 can handle 16 megs of 32bit memory on the
motherboard, and with the addition of the ZorroIII memory board made by
PP&S you can add another 64megs (or is it 128megs?) of memory, all of
which can be used by both the builtin HD controller, as well as the rest
of the system. You didn't mention if you had a flickerfixer, or other
delacer installed in your system, but the A3000 comes with a built in
hardware delacer, so that's an added bonus.
Unless you're using a toaster, which by your description it sounds like
you're not, the A3000 would have just as many open slots as your current
system, as the SCSI is built in as opposed to being on a ZII card like the
2091 is.
// -Mike Schiller
\X/ AMIGA! On AutoPilot in sunny Fort Lauderdale
Mike,
We spoke to Commodore this week about the a3000-25/50 systems. Guess
what? Commodore has no more, and no plans to get anymore. They do have
the A3000-25/100s at $1859.
So when the dealers and distributors run out of their current stock of
A3000-25/50s–that may well be all there is.
-mark=
So then if he had 2 Meg RAM on the 2630 then he could only have 6 meg RAM
on the expansion board, correct?
I recall that there are some bank limitations on the memory board
something like you had to add/remove memory in 2 MB increments or
something like that. We'll have to look at all these limitations when we
get the 2630.
Thanks for the information!
-J (Wandering around on AutoPilot)
Jay,
That's correct. Of course, the memory on the 2630 will be _faster_
than the 16-bit memory, so the optimal configuration would be 4 megs on
the 2630 (32-bit), and 4 megs on the other (16-bit) memory board.
Good luck….
– BobR
Understood that the 32-bit memory will be faster and so is more
desirable!
As I understand it the 2630 needs a ROM update to work with 2.0. Seeing as
it is a holiday I can't call the Amiga dealer right now, can some one tell
me what the ROM update will cost?
Thanks!
-J (Wandering around on AutoPilot)
Jay,
I believe the ROM upgrade is in the $20 to $30 category. I had to
do it to my 2620 (same ROM for either the 2620 or 2630) but that was a year
ago and I forget the exact amount.
Don
OK, Thanks for the information on the ROMs.
-J (Wandering around on AutoPilot)