Glen Slick wrote:
On Sat, Dec 27,
2008 at 6:41 PM, Jerome H. Fine <jhfinedp3k at compsys.to> wrote:
Using an M8190 quad 11/73 board is probably your
best choice with as much
memory as possible.
You wouldn't really want to put an M8190 KDJ11-B in a VT103 Q-Q
backplane instead of a Q-C/D would you?
Jerome Fine replies:
Not a problem. The M8190 will operate in both ABAB and ABCD backplanes.
I have successfully used an M8190 (a quad board) with a 4 MB memory board
(also a quad board) in a VT103 backplane that had been upgraded to 22 bits.
Note that since the VT103 backplane is ABAB on all 4 slots, it is not
possible
to use PMI memory as PMI memory. The PMI memory can, of course, be used
as ordinary memory.
I have heard that it is possible to alter the first 2 ABAB slots to be
ABCD so that
PMI memory can be used - or a Micro Vax II can be used. No details are
available.
An M7554 KDJ11-D/S might be more suitable for the Q-Q
backplane.
Address bits 18 - 21 are on BC1 - BF1 (SSPARE4 - SSPARE7)
BC1 - BDAL18L
BD1 - BDAL19L
BE1 - BDAL20L
BF1 - BDAL21L
A diagram would be helpful to identify the required points on the backplane.
By the way, I stated (incorrectly) that 16 solder points are needed.
Actually, 32 solder
points are required, 2 for each slot (both AB and AB on each slot) and 4
slots and
4 address lines for a total of 8 solder points per wire and 4 wires.
Lead based solder
is needed for this very old backplane.
Sincerely yours,
Jerome Fine