Accelerator Board
18 messages in this thread
Presently have an Amiga 2000, with Hard disk and 2058 Board, populated
with 4 Megs of RAM.
Am thinking of installing a GVP 28 MHz, (68030/'882 Plus 4 MB).
accelerator board.
QUESTIONS:
1). If/when the GVP board is installed, does it negate the use of the RAM
on the old 2058 Board ?
2). Can additional memory be added to the GVP board ? If so, how much more
?
3). If memory can be added to the GVP board, what sort of chips – SIMMS
or DRAM or what ?
Cannot find answers in the sales literature.
All the best…. HILARY
Hilary,
I don't have the GVP card, but I believe I can answer your questions.
1. The 16 bit ram on the 2058 board will still be available, but will be
used *after* the 32 bit ram is all "busy". The 32 bit ram is faster, and
has a higher priority – you want to use it "first".
2. I *think* 4 meg is the limit of the GVP board, but I'm not sure.
3. The GVP uses special "Nibble mode SIMMS", I believe. Not as easy to
find. But if the GVP is limited to 4 meg, and comes with that much already
– you won't have to worry about more chips.
Lloyd
The GVP board takes RAM in 4 meg increments. You can add another 4 for 8
meg total. If you do this you can't use 2058 board since the Amiga 2000
can only address 9 megs of total RAM. If you stick with 4 meg on the GVP
you can still use the 2058.
— Art via Amiga Whap!
Thanks for info' Regards…. Hilary
I'm afraid that Art is incorrect when he says that with 8 megs on
the
accelerator board you won't be able to use the memory on the 2058.
The 68000 chip in the stock amiga is limited to 9 megs of ram.
Tyhe
68030's limitation is 4 gigabytes or some other astronomical
figure.
You can only have 9 megs of 16 bit ram, but you can have as much 32
bit
ram as you can stuff into your computer (or as much as you can
afford).
Since the 68030 runs things when it is installed, you can use 8
megs
of ram on the 68030 board, and up to 9 megs of 16 bit ram.
Branden Beachy
72557,107
Branden,
No, Art is correct. The GVP, as well as the CBM 2630, do limit the
maximum memory on the machine to 9 meg. If the GVP board has 8Meg of 32bit
memory, then the 2058 will not be useable.
Dean
DKB Software
Dean,
Even if the memory is "ADDMEM'ed"? Is there something in AmigaDOS that
wouldn't permit this, given a CPU that could ADDRESS that ram?
Lloyd
Lloyd,
The 2630 and the GVP 3001 boards have thier memory placed in the Amiga
autoconfig space. ADDMEM will do nothing more than crash the machine if it
is tried under these circumstances. ADDMEM will only do some good if used
with memory that does not properly autoconfigure, and in that case will
allow more than 8Meg of FAST ram if you have a processor that will support
it. Currently neither the 2630 or the 3001 work with memory of this type.
Dean
DKB Software
Dean,
But if a 16 bit ram card is added to an Amiga with either the 2630 or
GVP accelerator, *AND* IF that ram card can be set to NOT autoconfigure
(and that's the big IF, I guess), THEN that ram should be able to be
ADDMEM'ed and used?
I *think* that's what this thread was originally about. Can a 16 bit ram
card be added to (and used by) a "MAXED OUT" 68020 or 68030 Amiga.
Lloyd
Lloyd,
Nope! The Amiga's memory space is limited to 16Meg maximum due to there
only being 24 address lines from the processor. (2^^24 = 16,777,216) The
original Zorro II specification supported just those address lines, so the
'020/'030 memory space cannot be used on any machine that supports just the
Zorro II bus. Out of the 16Meg of addressable space, 2Meg is reserved for
CHIP ram, 8Meg for FAST ram, 2Meg for I/O space and ROMs, 2Meg for the
custom chips, and finally 2Meg for motherboard ports. (parallel, serial,
disk, joystick ect…)
Even if the 16bit board is set for non-autoconfig, there is no memory
space available for it. The only place you could put more memory is
directly attached to the '030 card using memory space not accessable to the
Zorro II bus.
Dean
DKB Software
Now as I understand the issue as it was explained to me from Dave Hayne
(keep in mind that Dave speaks way over my head, most of the time :-> ),
the Amiga with its current operating system has a limit of 9 Megs of auto
configure space, a memory card like the A2058 from CBM can only put its
memory in that auto-configuring space, however a CPU board like the A2630
which can support much more than 9 MEGS via a daughter board, can put any
of that RAM in space other than autoconfig and still have access to it via
the 68030. While you have less than 9 MEGS total it only makes sense to
put it all in auto-config, but lets say you have a 6 MEG A2058 and a 4 MEG
A2630 plus 1 MEG of CHIP, then you would want the all the chip RAM and the
A2058's RAM in auto-config (since thats the only place it can go) and 2
MEGS of the A2630's MEM to fill up the auto-config space, that would leave
an additional 2 MEGS of the A2630's MEM to be used for other non
auto-config uses. Now the two problems with this scheme as that you are
giving up signifigant speed by putting the slower 16 bit memory in
auto-config instead of the faster 32 bit RAM. The other problem is that
any memory which is not auto-configed needs custom applications to take
advantage of it. Examples Dave has given include using it to store a
faster copy of the Amigas ROMS, using it for a RAM-Disk, used as a buffer
for a specially designed video board, etc…
-Jason-
Jason,
The limitation is not really the OS as much as it is the hardware. If we
ignore the '030 for now, the Amiga is only capable of accessing 2Meg of
CHIP, and 8Meg of FAST ram. This limitation is because the current hardware
is only capable of accessing 16Meg, and the memory map is such that there
is no extra room for more memory. Due to these hardware restrictions, the
current OS (1.3) only supports 8Meg of autoconfig memory space. If you
ADDMEM the memory in, (ie, non-autoconfig) then the OS will use it just
fine.
Now, when an '030 is installed, you can hook extra memory directly to it
to provide more than 8Meg of memory. However, it will not autoconfig unless
it goes into the same area of the memory map as the standard '16 bit'
memory does. If you are willing to ADDMEM it, then you can add up to 2Gig
of additional memory.
Since to autoconfigure the '030 memory requires that you place it in the
standard memory map, this means that you are still limited to 8Meg of FAST
ram in the machine. The new OS (2.0) and the latest machine (3000) have an
'030 standard, and a 32bit expansion bus to support. Because of this, there
has been support added that allows considerably more than 8Meg of memory. I
believe the current limit is a little over 1Gig.
For the sake of clarity (which I may have missed anyway) I have ignored
the $C00000 memory which autoconfigures under 1.2 and up. This area adds
approximetly 1.5Meg of autoconfig memory to the system.
Dean
DKB Software
Hilary,
Your memory board could be a problem. I bought a GVP accelerator. At
the time I had just an A2000 and a 2 Meg memory board. I think the model
number of the board was 2052, but it might have been 2058. It was one of
the first memory board made by CBM for the A2000. I did not have a problem
getting the system to address the memory, but I did have a problem in that
the board would overheat and cause the computer to GURU. This was verified
by GVP as a design problem with the memory board. From my experience I can
firmly say that either it will or won't work. The only way to find out is
to try. Maybe you could find someone with an accelerated system to try it
on.
<<< Michael Shea >>>>
<<< 76665,3360 >>>>
Michael,
I know the the 2052's (older, 2 meg boards) have problems with
accelerated Amigas, but I don't think the 2058's do.
Lloyd
Lloyd,
Sounds good for Hilary then. I just could not remember the model number
of my board. I still have it (gathering dust), but the number is not even
on the board.
<<< Michael Shea >>>>
<<< 76665,3360 >>>>
Thanks Michael. Will keep a fire extinguisher handy! HILARY
Hilary,
I do not know if you read them, but there were some other messages in
this thread that suggested you should not have any problems. Good luck.
<<< Michael Shea >>>>
<<< 76665,3360 >>>>
Yep – thanks. Got a somewhat complex answer(s) to what I thought (and
hoped) was a simple question !
All the best. HILARY