28 Jul
2006
28 Jul
'06
6:22 p.m.
On Friday 28 July 2006 21:14, Roy J. Tellason wrote:
On Thursday 27 July 2006 07:08 pm, Chuck Guzis wrote:
Nope. 64kB address space - 8kB I/O page (32kW - 4kW = 28kW).
Unlike some other things of the era (like the HP 1000 series), the address
gives you what byte location of memory something is at, not which word
location in memory.
Note that things after the LSI-11/2 which includes an MMU (or any Unibus/11
that has an MMU) can physically address more ram, but cannot logically
address more than 32kW...
Pat
--
Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
Now, back then, it was even more confusing. The
"K" that IBM was talking
about on its S/360 machines was 8-bit bytes; the CDC was talking about
60-bit words.
I just bumped into that one in an email conversation with somebody, who
said that an LSI-11 would only handle 56K of ram. And my recollection (?)
is that this referred to 56K _words_ as opposed to bytes.