8 Dec
2016
8 Dec
'16
10:20 a.m.
Rich Alderson wrote:
From: Chuck Guzis
Sent: Monday, December 05, 2016 6:15 PM
I know nothing about physical magtapes. I have seen this comment about
the MIT ITS machines:
I've seen PDP-10 9-track tapes done two
ways--one character per frame
and then 4 frames (36 bits) with 5 7-bit characters and the sign bit
left over.
Neither of those is entirely accurate. 9-track tapes on the PDP-10
[...] DM had the only 9-track tape drive; the other machines
had 7-track
tapes, as befit 36-bit machines.
So I suppose many ITS tapes would have stored six frames per word.