3 Aug
2016
3 Aug
'16
8:57 a.m.
From: Steven Malikoff
I'm wondering if there are any more differences
apart from the lack of
the two high address switches?
According to the -11/15-20 processor manual (pg. 2), the differences between
the two are i) the -15 has only one hardware interrupt level, not four (the
latter is optional), and ii) power-fail restart is an option, not standard.
Presumably the /15 could not run one of those KT-11
paging units
I'm not sure how the KT11-B works, but my _suspicion_ (going from the
pictures of that one that sold on eBay) is that it's not part of the CPU, but
a UNIBUS device, which maps part of the UNIBUS which the CPU _can_ see (i.e.
in the 0-56KB range) up to higher addresses, where the 'extra' memory is
configured. If that supposition is correct, it would work equally well on any
-11 (without built-in memory mapping in the CPU).
Noel
3 Aug
3 Aug
9:44 a.m.
On Aug 3, 2016, at 8:57 AM, Noel Chiappa <jnc at
mercury.lcs.mit.edu> wrote:
...
I'm not sure how the KT11-B works, but my _suspicion_ (going from the
pictures of that one that sold on eBay) is that it's not part of the CPU, but
a UNIBUS device, which maps part of the UNIBUS which the CPU _can_ see (i.e.
in the 0-56KB range) up to higher addresses, where the 'extra' memory is
configured. If that supposition is correct, it would work equally well on any
-11 (without built-in memory mapping in the CPU).
That sounds plausible. It would have to be a Unibus bridge type device, i.e., it
terminates the Unibus from the CPU, and at the other end originates a Unibus with mapped
addresses on it. It can't just be a regular Unibus device because it has to modify
the addresses that come from the CPU. That assumes the KT11-B does only memory mapping,
not the other things that other MMUs do (user vs. kernel mode, I/D space, that sort of
stuff).
paul
2910
days inactive
2910
days old
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