LGP-21 and LGP-30 memory, number, address explained

From: Tom Jennings <tomj_at_wps.com>
Date: Thu Sep 16 20:26:02 2004

These machines have a peculiar (to me) memory format, it's not really
obvious, so I worked it out and wrote it up here


simh adds to the confusion, somewhat, because it displays memory by
default in "normal" mode. e -m address does the right thing for
instructions, but it's missing a -option to display numerical data; for
example a "2" stored in LGP memory shows as "4" in simh because of the
spacer bit.

Memory is 31 bits wide, the accumulator is 32 bits...
Received on Thu Sep 16 2004 - 20:26:02 BST

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