17 Mar
2015
17 Mar
'15
4:30 p.m.
From: John Wilson
I think Guy's MEM11 is going to be way cooler. ...
I'll be doing a new
rev one of these months ... and then I'll certainly make them
available, but not seriously expecting anyone to order one. Guy's MEM11
is nicer!
Yeah, but for some machines I wouldn't mind having pure memory boards.
it plugs into the A/B positions of a MUD/SPC slot,
which makes it
useless on an 11/20 which doesn't have those (right? unless you add a
BA11K?)
I haven't checked, but I suspect there might be a way to power like a DD11-C
through some sort of conversion plug, but I'm not up on 11/20 power (would
have to read the H720 manual, which I'm too lazy to do).
Naturally I've gotten way sidetracked writing that
firmware ...
Totally out of hand.
Hah, what else is life for? :-)
it sounds (from the MS11P manual) as if the 11/24 and
11/44 extended
Unibus would be easy to support as an option (seems like the four extra
address bits on AN1, AP1, BE1, and BE2 are all that's new
I'm pretty sure. If you look at the MS11-M prints (FMPS #742, pg. 4), they
have a jumper called 'UNIBUS/Extended UNIBUS' and basically all it does is
disable listening to those 4 extra bus address lines. (It also affects CSR
stuff, but not the basic memory operation, other than disabling the 4 extra
address lines.)
I've got some MS11-P cards (which are now really cheap, compared to real
UNIBUS MOS memory) here, and I'm planning on hacking them so they are UNIBUS
cards, via a similar hack. (I'm not going to use MS11-M cards because they
use some wierd voltage that's only easily available in the 11/44; the
MS11-P's use +5V only.)
Noel