glen herrmannsfeldt wrote:
In the stories I remember, but never actually did or saw anyone do,
one punched TXT cards to write over the mistake bytes.
As far as I remember TXT have a start address and length such that
one could do it. A table of the 256 possible punch combinations
and the resulting bit patterns would be needed, though.
The description I know of for the object module format is in
the Linkage Editor PLM, for sale by IBM up until a few years ago.
It should also be on bitsavers.org.
as mentioned in previous post ...
http://www.garlic.com/~lynn/2006g.html#43 Binder REP Cards (Was: What's
the linkage editor really wants?)
http://www.garlic.com/~lynn/2006g.html#44 Binder REP Cards (Was: What's
the linkage editor really wants?)
i got quite accomplished at reading and multi-punching (hex) punch codes
in TXT cards ... having memorized all possible punch codes and their hex
counterpart and hex codes for all instructions; also served in reading
printing hex storage dumps and/or examining the contents of storage
using the front panel lights.
I have old CMS Program Logic Manual (360D-05-2-005, Oct, 1970), starting
pg. 292 and CP67/CMS User's Guide (GH20-0859-0), pgs 521-523 which has
format description for ESD, TXT, RLD, END, REP, ICS, SLC, etc cards
which i've partially reproduced sections of in previous posts.
detail of ESD card format (from posting in bit.listserv.ibm-main in 2001):
http://www.garlic.com/~lynn/2001.html#8 finding object decks with
multiple entry points
detail of SLC, ICS, REP, ESD formats from posting to
alt.folklore.computers in 2001
http://www.garlic.com/~lynn/2001.html#14 IBM Model Numbers (was: First
video terminal?
detail of TXT format (from posting to alt.folklore.computers in 2001)
http://www.garlic.com/~lynn/2001.html#60 Text (was: Review of Steve
McConnell's AFTER THE GOLD RUSH)
from above:
col
1 12-2-9 / x'02'
2-4 TXT
5 blank
6-8 relative address of first instruction on record
9-10 blank
11-12 byte count ... number of bytes in information field
15-16 ESDID
17-72 56-byte information field
73-80 deck id, sequence number, or both
in 360 assembler, the first TITLE statement with a non-blank name field
would place that name field in cols 73-80 of all output object
cards/records.
the above description is repeated in
http://www.garlic.com/~lynn/2001m.html#45 Commenting Sytles (posted to
alt.folklore.computers in 2001)
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