johnwgilmore0...@gmail.com (John Gilmore) writes:
> The original System/360 scheme was simple and in its way elegant.
> 01F---decodable unambiguously into (multiplexor) channel 0, control
> unit 1, and that control unit's device F or 15---was, for example, the
> usual device address of the card punch circa 1965, when punches were
> still real rather than virtual devices.
trivia ... 009 was 1052-7 console
00C was 2540 reader
00D was 2540 punch
00E was 1403 printer
some other configurations had 01F as 1052-7 console address (instead of
009) ... making the "controller" abstraction on the multiplexor channel
slightly more consistent.
tale of cp40
http://www.garlic.com/~lynn/cp40seas1982.txt
done at the science center in the 60s .... some past posts
http://www.garlic.com/~lynn/subtopic.html#545tech
cms started out operating system being done on regular 360/40 with
interactive commands on the 1052-7 operator's console
cp40 was hardware modifications to 360/40 providing virtual memory, cp40
then implemented 360/40 virtual machines ... and cms ran on either
bare-hardware or in cp40 virtual machine.
when 360/67 became available standard with virtual memory, cp40 morphed
into cp67. the default cms virtual machine configuration tended to stay
the same that it started out from the "real" 360/40 configuration
(256kbyte real memory configuration).
additional history can be found in documents at Melinda's website
http://web.me.com/melinda.varian/Site/Melinda_Varians_Home_Page.html
this talks about 360/40 & 360/50 having integrated console at 01f
(aka when it was not at 009):
http://en.wikipedia.org/wiki/IBM_System/360
cp67 default configuration for cms virtual machine:
http://www.bitsavers.org/pdf/ibm/360/cp67/
GH20-0859-0_CP67_Version_3_Users_Guide_Oct70.pdf
pg. 5 ... shows the 009 configuration for 1052-7 console
note the cp67 users guide also described 2741, 1052, and tty terminals
when cp67 was originally delivered to the univ, it only has 2471 & 1052
terminal support ... but had dynamic terminal type identification
support ... being able to use the SAD controller command to switch
between the 2741 and 1052 line-scanner for each port/address.
the univ. had a lot of tty terminals and so I had to add tty support
(which was picked up and released with the product). I looked at the
2741/1052 and added the tty support so it also did dynamic terminal type
identification ... being able to use SAD command to dynamically switch
the different (2471, 1052, & tty) line-scanners for each port.
I then wanted to do a single dial-up "hunt-group" for dial-up terminals
... aka a common pool of phone numbers/modems with a single dial-in
number for all terminals. It turns out that dynamic worked for leased
lines ... but wouldn't work for common pool for all dial-up terminals.
The problem was that while it was possible to dynamically switch the
type of line-scanner (with SAD command) on per port basis ... the line
speed was hard-wired for each port.
This was somewhat the motivation for the univ. to start a clone
controller project ... which could do both dynamic termainal type as
well as dynamic line speed (i.e. 2741 & 1052 had the same line speed
... but different line-scanner ... tty had both a different line-scanner
as well as different line speed). later four of us get written up
as being responsible for (some part of) clone controller market.
misc. past posts mentioning clone controller
http://www.garlic.com/~lynn/subtopic.html#360pcm
This reference has clone controller competition a primary motivation
for the Future System effort:
http://www.ecole.org/Crisis_and_change_1995_1.htm
Then Ferguson & Morris, Computer Wars: The Post-IBM World, Times Books,
1993 ... describe the distraction of the Future System (and internal
politics killing 370 efforts) allowed clone processors to gain market
foothold ... misc. past posts mentioning Future System
http://www.garlic.com/~lynn/submain.html#futuresys
--
virtualization experience starting Jan1968, online at home since Mar1970
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