8 Apr
2021
8 Apr
'21
2:48 p.m.
From: Jerry Weiss
I always wondered why the RKV11-D was only 16 bit
addressable.
The manual (EK-RKV11-OP-001) says: "Since the 11/03 BUS structure has no
provision for extended addressing, no connection is made to the bus from
these [XM] bits on the RKVII-D." (pg. 3-5).
The DEC RK05 disk subsystem cost $10K list circa 1978
(drive, RKV-11D
controller and cabinet), so this wasn't a trivial purchase.
Interesting. Where did you see that listed, just out of curiosity? (I looked
in the Jan '84 PDP-11 Systems and Options, my copy of which just showed up,but
that's too late; I could probably find it if I pawed through all my DEC sales
literature, but I'm too lazy... :-).
Noel
9 Apr
9 Apr
7:45 a.m.
On 4/8/21 4:48 PM, Noel Chiappa via cctalk wrote:
Certainly the published interface is constrained by what was
"officially" released.?? Just pondering if there was an internal
engineering roadmap from 16->18->22 bits around this time or did things
evolve more discretely?
My reference here is "A source handbook for Digital Equipment
Corporation LSI-l I-compatible products"
https://link.springer.com/content/pdf/10.3758/BF03205335.pdf
????????? Jerry
From: Jerry
Weiss
I always wondered why the RKV11-D was only 16 bit
addressable.
The manual (EK-RKV11-OP-001) says: "Since the 11/03 BUS structure has no
provision for extended addressing, no connection is made to the bus from
these [XM] bits on the RKVII-D." (pg. 3-5). The DEC RK05
disk subsystem cost $10K list circa 1978 (drive, RKV-11D
controller and cabinet), so this wasn't a trivial purchase.
Interesting. Where did you see that listed, just out of curiosity? (I looked
in the Jan '84 PDP-11 Systems and Options, my copy of which just showed up,but
that's too late; I could probably find it if I pawed through all my DEC sales
literature, but I'm too lazy... :-).
Noel 
8:56 a.m.
Certainly the published interface is constrained by
what was
"officially" released.?? Just pondering if there was an internal
engineering roadmap from 16->18->22 bits around this time or did things
evolve more discretely?
I think it evolved. Remember there was one type of core memory for the
11/03 that only worked in a 16 bit box as did the little 4k memory
boards that required the 11/03 to do refresh cycles. Maybe the MSV11-CD
memory board (had one of those) as well. I think it used "bits 16-17"
for the +15,-5 or something like that and plugging an 18 bit card into a
slot like that would cause the usual fireworks.
But back in the beginning your choice was RX01 floppies (interrupt so
they didn't care), or the RKV11.
I've got the 1975 or so version of the 11/03 short book, I can take a
look. But I remember very clearly the insanity of the RLV11 controller
board with the whole BA11-S requirement for the CD bus (which was
repurposed as the PMI on the 11/83). Always wondered if you could run an
RLV11 in slots 2-3 on a BA23 box. Probably.
C
1353
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1354
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cz＠alembic.crystel.com -
jnc＠mercury.lcs.mit.edu -
jsw＠ieee.org