31 Oct
2002
31 Oct
'02
9:20 a.m.
I just realized that my reply to Jerome's inquiry
about the
LSI-11 module with five chips was probably wrong. IIRC, the
LSI-11 chip set consists of the control chip, data chip, and
two MICROMs for the base instruction set. The EIS/FIS (KEV11)
is a single additional MICROM. So the original quad-height
LSI-11 module would have four 40-pin chips without the EIS/FIS,
or five with.
Correct... and with 5 sockets, there would be one left over
for either the EIS/FIS option or WCS, not both.
Was it the LSI-11/2 half-height module that sometimes
used
a hybrid with two MICROMs? If so, it was probably the two
microms that implemented the standard instruction set, in
order to leave a socket open for the KEV11.
Actually, I've seen the dual microm used on both 11/03s and
on 11/2s, as well as on the PDT (I have a couple of those
which have been so modified). The 3007/3010 chips are
combined into one dual microm. This would allow boards
with only 4 sockets (like the PDT) to add EIS/FIS.
On the 11/23 and 11/24, some of the chips were also on
dual-chip
hybrids.
The FPU chip for the 11/23,24 was a dual carrier chip. The
CIS option was a hex-carrier chip. It had 6 of those small
gold chips on it, and spanned two sockets of the 11/23[+]
board. I don't know if it could go on the 11/24. (I have a
KDF11-B with one of these chips on it).
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | email: gentry at zk3.dec.com (work) |
| Unix Support Engineering Group | mbg at world.std.com (home) |
| Hewlett Packard | (s/ at /@/) |
| 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 (DEC '77-'98) | required." - mbg KB1FCA |
+--------------------------------+-------------------------------------+