Early 360 machines (Was: Front panel switches - what did they do?)

Paul Berger phb.hfx at gmail.com
Wed May 25 21:22:02 CDT 2016

On 2016-05-25 10:43 PM, Chuck Guzis wrote:
> The train printers did have an obvious advantage over both the drum 
> and band printers. In our shop, we printed lots and lots of core 
> dumps. Add to a full CM dump, a couple of million words of ECS and the 
> "0" characters wore out pretty quickly. You could replace a train 
> slug, but had to live with "fuzzy" zeroes until someone higher up 
> couldn't stand the printout. I recall reading a set of pre-publication 
> Univac 1108 manuals that were printed on a badly-adjusted drum 
> printer. It gave me headaches. --Chuck 
Speaking of dumps I remember an engineer friend telling me that at the 
university that he went to they had a CDC Cyber system and they 
discovered that you could initiate a dump from any workstation, and the 
system would dump out to the printer and while it was dumping the whole 
system came to a halt.... guess what the students where fond of 
doing......  It would seem to me that something like that should have 
been more restricted.

In the first couple years of working as an electronic technician, we 
still had software people in the branch office, and I remember being 
blown away by this one guy.  He came into the office with a MVS dump 
which was a 6-8 inch stack of paper and on the top of each was a header 
with the IAR  and register contents when the system trapped. He looks at 
the IAR and digs into the dump to find that address and then he starts 
working backwards, unassembling the instructions in his head and after a 
few minutes he points to a spot in the dump and says "yes there it is, 
there is where it started to go wrong"


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