"Doug Winterburn" wrote in message
...
LDosser wrote:
"Morris Dovey" wrote in message
...
On 4/11/2010 12:27 AM, LDosser wrote:
"Morris Dovey" wrote in message
...
On 4/10/2010 9:05 PM, LDosser wrote:
"Morris Dovey" wrote in message
...

Sorry, but after spending more than a half-century developing
software
(link in sig),

I'll see your Spectra 70/45 and raise you an RCA 501 and 301. )

You win - besides, the 70/45 was just a thin film approximation to a
360/30 (same instruction set and I/O devices, but had a sexier front
panel)

Operating that 501 was like playing an organ ...

When we got the 70/45s I went to supervision. All the fun had been
taken
out of operation.

Half decent pic he

http://archive.computerhistory.org/r...6273.fc.lg.jpg


Might even be me in the photo - wore a suit just like that. )

Hmm - I may have seen one of those. At one point in '65 the outfit I
was working for needed more capacity so one Saturday I was loaded into
a cab with a couple dozen tapes to borrow the 70/45 at NIPSCO
(Northern Illinois Public Service Co).

They still had their pre-Spectra system (just in case) and it looked a
lot like that.

That trip was my intro to RCA's high-speed tape drives - which, as I
discovered, meant that if they glitched they could suck about 250' of
tape into a vacuum column faster than an operator could say ****, and
pack it so tight that it took a letter opener to pry out.

By the third time it'd stopped being even mildly interesting. (Hit the
COIN button, abort the run, pry the tape out of the drive, rewind the
other drives, mount a backup tape, and re-start the program. Ugh.

Yeah, those babies were Fun. We used to have contests to see how quickly
you could get all the drives off BT and then rewound - using the
console. Then there was the tape mount rodeo! And with 3/4" tape, you
did some upper body work every shift. When we got the Spectras, I wrote
some cod to emulate the tape drives using the spectra disk drives.
Really speeded up the stuff we still had to run using the 501 and 301
emulators. Drove the 501 prototype for a couple weeks in Camden, NJ.
IIRC, RCA had several in Viet Nam. Supposedly one running in a tent,
which I can believe as ours could take all kinds of a licking and keep
on ticking!

Did they have a goony bird paper tape reader? Sometimes you had to use
the eraser on the end of a pencil to keep the pt reader from snapping
the tape. Idea was to use an Unsharpened pencil - DAMHIKT! I used to be
able to read the paper tape manually.

Ah, the tape emulator idea. We had a 360/40 and got a 7094 free from
the Navy. Also got an IBM TICU (Tape Intersystem Connecting Unit). It
connected to the 7094 and looked exactly like 10 tape drives. It also
connected to the 360 and didn't look like anything without some code
work. I got the job of writing the tape emulator program on the 360.
We were running OS/MFT and I had all of 8K for code and buffers. The
challenge was the 7090 could read/write 32K words of 36 bits in one
whack. It was an interesting I/O chaining challenge with CCW's imbedded
in the disk buffers. It also depended on a seek of one cylinder taking
no more time than one rotation of the disk and not having any
re-assigned tracks. Those were the days...


We thought they'd never end ... As late as 1983 I was still keying stuff in
on the front panel of an SDS Sigma 7 - using my nose. ) Had to Manually
calculate overlays and break up the code to fit.

Worked on a port of Unix to PDP Micro J/11 only to find out two years later
that the company hadn't licensed it from ATT.