Charlie Gibbs <
cgibbs@kltpzyxm.invalid> writes:
On a PPOE's system it took 40 minutes to assemble a 2000-card source
code deck. When I got my own assembler working, it met one of my
design goals of being twice as fast - so it only took 20 minutes to
assemble the same program. For us programmers, who had rock-bottom
priority on the machine, that meant I only had to beg for half as much
machine time.
I took 2credit hr intro to fortran/computers and at end of semester I
was hired to rewrite 1401 MPIO in assembler for IBM 360/30. The univ was
getting 360/67 for tss/360 replacing 709 (tape->tape) and 1401 (unit
record front end) and got 360/30 temporarily (replacing 1401) pending
availability of 360/67. univ. shutdown datacenter on weekends and I got
the whole place dedicated (although 48hrs w/o sleep made monday classes
hard). I was given a bunch of hardware and software manuals and got to
design and implement my own monitor, device drivers, interrupt handlers,
error recovery, storage management, etc ... and within a few weeks had a
2000 card assembler program.
I then used conditional assembler option to implement 2nd version with
os/360 sysstem services (get/put, dcb macros, etc). The stand-alone
version took 30mins to assemble, the OS/360 version took 60mins to
assemble (each DCB macro taking 5-6mins). Later I was told that the
IBMers implementing the assembler had been told that they only had
256bytes for instruction lookup (and DCB macro had an enormous number of
2311 disk I/Os).
Within a year, the 360/67 shows up (replacing 709 & 360/30) but tss/360
never came to production fruition so ran as 360/65 with os/360 ... and I
was hired fulltime responsible for os/360 (keeping my dedicated weekend
time). Originally student fortran ran under a second on 709, but
initially over a minute on 360/67 with os/360. My first sysgen was R9.5
and I add HASP and it cuts student fortran in half. Then with R11
sysgen, I start redoing stage2 to carefully place datasets and PDS
members to optimize arm seek and multi-track search, cutting another
2/3rds to 12.9secs, Student fortran never got better than 709 until I
install Univ. of Waterloo WATFOR.
Along the way, CSC comes out to install (virtual machine) CP/67 (3rd
installation after CSC itself and MIT Lincoln Labs) and i mostly got to
play with it during my weekend dedicated time.
https://en.wikipedia.org/wiki/Cambridge_Scientific_Centerhttps://en.wikipedia.org/wiki/CP-67Initially i rewrote lots of CP67 to optimize running os/360 in virtual
machine. My os/360 test stream ran 322secs on real hardware and
initially ran 856secs in virtual machine (534secs CP67 CPU), within a
few months I have CP67 CPU down to 113secs and I'm invited to the Spring
Houston IBM mainframe user group meeeting to participate in CP67
announcement.
Then before I graduate, I'm hired fulltime into a small group in the
Boeing CFO office to help with the consolidation of all dataprocessing
into independent business unit. I though that Renton datacenter was
possibly largest in the world, a couple hundred million in IBM 360
stuff, 360/65s were arriving faster than they could be installed, boxes
constantly being staged in the hallways around the machine room. Also a
lot of politics betweeen Renton director and CFO who only had a 360/30
up at Boeing field for payroll (although they enlarge the room to
install a 360/67 for me to play with when I wasn't doing other stuff).
-- virtualization experience starting Jan1968, online at home since Mar1970
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