John W Kennedy wrote:
Robert Maas, http://tinyurl.com/uh3t wrote:
John W Kennedy <[EMAIL PROTECTED]> wrote:
JWK> Into the 60s, indeed, there were still machines being made
JWK> that had no instruction comparable to the mainframe BASx/BALx
JWK> family, or to Intel's CALL. You had to do a subprogram call by
JWK> first overwriting the last instruction of what you were
JWK> calling with a branch instruction that would return back to
JWK> you.
HUMMmmmmm! Brings back memories. The Monroe-bot 9, Olivetti,
Sperry-Rand and the rest. I came in on the IBM-360 original series in
the mid-60'. Subroutine docs were important. You needed to know from
which register the sub was going to use/store the return address. (As
well as which registers it used for what both incoming and out going.)
it's been so long I forget the actual mnemonics.
something like:
.
.
load R12,rtn89 (alt)
jump sub32 sub32: sub32:
rtn89: stor R12,safe .
. . .
. . jump R12
rtrv R12,safe
jump R12
Programs were simple then. Card, paper tape, mag tape IN and card, paper
tape, mag tape and hardcopy paper OUT. The monitor was the guy who
looked at the flashing lights on the metal panel. And to change a
program on the 1401 usually required the soldering iron, patch cables
and a patch board! And a new deck of cards containing the next program.
Don't use a used deck 'cause then the reader will eat the cards. :)
I helped Chevron East convert from 1401 to 360. Long ago, far away and
with no intention of returning to those long long hours in 'the room'.
LSI??? Ha-Ha. Anyone remember the word transistor?. Power supply was
tubes. However, core was 3-axis iron core. That I miss.
17 flip switches
set 1-16 & flip 17 to load first half word
set 1-16 & flip 17 to load 2nd half word 1st boot word ready
.
.
core boot loaded mag master 1 and read next sequence which ...
only took 45 min. to boot if first effort succeeded. Otherwise...
it was going to be a long day....
The "Good 'Ole Days"? Point of view. Code was tight and comradely was
what kept us going. The long hours and being shunned by company people
as gargoyles down there or some such - I can do without.
...(snip)
Steve
[EMAIL PROTECTED]
OH- If the sub might be called other than as if in-line, an area of
memory was given to safe and it would be incremented/decremented upon
use. safe was just an address. safe dw 40 or whatever
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