16 Jul
2020
16 Jul
'20
1:34 p.m.
Hi all --
Picked up a board advertised as a "4mb memory board" for a VAX-11/750.
It's made by Dataram and I'm unsure of the model number, based on photos of
it. I just noticed that rather than being a hex-height board that goes in
the memory backplane, it looks like a board that goes in the main CMI
backplane. It also appears to have 16mb of ECC memory on it, rather than
4mb.
My thought is either (1) it's not actually for an 11/750 (in which case I'm
curious what it would go into), or (2) it completely replaces the memory
controller and standard memory and gives you 16mb in the 750. (Or it could
be that it's something else entirely.)
If anyone has any ideas or has a source of information, let me know. I put
up a few pictures here:
http://yahozna.dyndns.org/scratch/dataram/
Thanks as always,
- Josh
16 Jul
16 Jul
1:41 p.m.
On Thu, Jul 16, 2020 at 1:34 PM Josh Dersch <derschjo at gmail.com> wrote:
Hi all --
Picked up a board advertised as a "4mb memory board" for a VAX-11/750.
It's made by Dataram and I'm unsure of the model number, based on photos of
it. I just noticed that rather than being a hex-height board that goes in
the memory backplane, it looks like a board that goes in the main CMI
backplane. It also appears to have 16mb of ECC memory on it, rather than
4mb.
My thought is either (1) it's not actually for an 11/750 (in which case
I'm curious what it would go into), or (2) it completely replaces the
memory controller and standard memory and gives you 16mb in the 750. (Or
it could be that it's something else entirely.)
If anyone has any ideas or has a source of information, let me know. I
put up a few pictures here:
http://yahozna.dyndns.org/scratch/dataram/
Thanks as always,
- Josh
I think I may have answered my own question here; looks like it's for a VAX
8000 series:
https://www.wikiwand.com/en/VAX_8000
<https://www.wikiwand.com/en/VAX_8000?fbclid=IwAR3QoE8s_7NE3ILHqMIuxGHJ4m_qR_TXn_J5jrczGVtbD8sPY8tWvhPjSzw>
- Josh
1:53 p.m.
On Thu, Jul 16, 2020 at 4:42 PM Josh Dersch via cctalk
<cctalk at classiccmp.org> wrote:
On Thu, Jul 16, 2020 at 1:34 PM Josh Dersch
<derschjo at gmail.com> wrote:
That makes more sense than a board that replaces the memory controller.
IIRC, the 11/750 has an architectural limit of 14MB of RAM, but that
might just be because of 8 memory slots (individual select lines), the
implementation of the L0016 memory controller, and that's what you can
hit with 2X 4MB boards + 6X 1MB boards. I _think_ if you could have
gone to 16MB of RAM, DEC might have made a memory controller that
could control 3X 4MB boards + 4x 1MB boards or 4X 4MB boards, but they
did not.
I installed the extra memory line wire on the backplane of our 2MB
11/750 (and installed the L0011), but we never made that final jump
Picked up a board advertised as a "4mb
memory board" for a VAX-11/750...
I think I may have answered my own question here; looks like it's for a VAX
8000 series: from L0011 -> L0016. By the time that was
available, we weren't going
to spend that kind of money on that machine. It
still has 8MB to this
day.
-ethan
2:10 p.m.
On Thu, Jul 16, 2020 at 1:42 PM Josh Dersch via cctalk
<cctalk at classiccmp.org> wrote:
I think I may have answered my own question here; looks like it's for a VAX
8000 series:
https://www.wikiwand.com/en/VAX_8000
<https://www.wikiwand.com/en/VAX_8000?fbclid=IwAR3QoE8s_7NE3ILHqMIuxGHJ4m_qR_TXn_J5jrczGVtbD8sPY8tWvhPjSzw>
Obviously now you need to pick up a VAX 8000 system.
2:38 p.m.
On Thu, Jul 16, 2020 at 2:11 PM Glen Slick via cctalk <cctalk at classiccmp.org>
wrote:
On Thu, Jul 16, 2020 at 1:42 PM Josh Dersch via
cctalk
<cctalk at classiccmp.org> wrote:
Obviously now you need to pick up a VAX 8000 system.
That does seem to be the most logical next step, yes :).
- Josh
I think I may have answered my own question here; looks like it's for a
VAX
8000 series:
https://www.wikiwand.com/en/VAX_8000
<
https://www.wikiwand.com/en/VAX_8000?fbclid=IwAR3QoE8s_7NE3ILHqMIuxGHJ4m_qR…
3:12 p.m.
On 16/07/2020 22:38, Josh Dersch via cctalk wrote:
On Thu, Jul 16, 2020 at 2:11 PM Glen Slick via cctalk
<cctalk at classiccmp.org>
wrote:
I think I have a load board for one somewhere ... No idea how I got it,
but if you end with with a VAX 8000 before I do, let me know and we can
cut a deal :-)
Antonio
--
Antonio Carlini
antonio at acarlini.com
Obviously now you need to pick up a VAX 8000 system.
That does seem to be the most logical next step, yes :).
- Josh
17 Jul
17 Jul
9:46 p.m.
On Thu, Jul 16, 2020 at 5:11 PM Glen Slick via cctalk
<cctalk at classiccmp.org> wrote:
On Thu, Jul 16, 2020 at 1:42 PM Josh Dersch via
cctalk
<cctalk at classiccmp.org> wrote:
One with an NMI bus, naturally. The low-end 8000s are pure VAXBI (I
have an 8300).
I'm sad I had to abandon a VAX 8530 when Software Results closed down
in 1993. It was a bit large for home use, and I was never going to
have 3-phase power for it.
AFAIK, it got left for our landlord to dispose/sell off. We only paid
$5000 for it a year earlier (nobody wanted them in the early 90s) so
it's unlikely he found a quick buyer.
-ethan
I think I may have answered my own question here; looks like it's for a VAX
8000 series:
https://www.wikiwand.com/en/VAX_8000
<https://www.wikiwand.com/en/VAX_8000?fbclid=IwAR3QoE8s_7NE3ILHqMIuxGHJ4m_qR_TXn_J5jrczGVtbD8sPY8tWvhPjSzw>
Obviously now you need to pick up a VAX 8000 system.
1618
days inactive
1620
days old
6 comments
4 participants
participants (4)
-
a.carlini＠ntlworld.com -
derschjo＠gmail.com -
ethan.dicks＠gmail.com -
glen.slick＠gmail.com