18 Jan
1999
18 Jan
'99
10:52 a.m.
In einer eMail vom 13.01.1999 07:49:30, schreiben Sie:
<<
John G. Zabolitzky wrote:
6 bit characters were quite the standard BEFORE /360
days, say for
CDC 6600, CDC 7600 (the most powerful computers from mid-60s until
the appearance of the CRAY-1 machines, forerunners of the Cyber 170
series),
or IBM 7030, IBM 7090, IBM 7094 say, back in the
'60s.
They were not called bytes, and could not be addressed directly;
there were 36 bit or 60 bit words, and shift / logical instructions used
for
character manipulation. In fact this is probably the
origin for the
six character namelength limit in FORTRAN IV : 6 chars x 6 bits = 36 bit
word.
Eric Smith wrote:
All generally correct except for the 7030 (Stretch). Stretch used
variable-length fields from 1 to 64 bits, and its native character set used 8
bits. The integer arithmetic instructions, however, were specificially
designed to be useful on character data types from 4 to 8 bits.
http://www.brouhaha.com/~eric/retrocomputing/stretch/
>
It seems I got these IBM model numbers confused. I think I meant the
7040 (and of course we can go back to the earlier tube computers, 704 and
709).
Eric, you seem to have quite some info on the Stretch; do you have any
source of (original or other doc) on this or the other early IBM computers ?
There is of course the book by Bashe et al, but I find it difficult to
locate more info.
John G. Zabolitzky