[Discuss] Old computers Re: (OT) Steve Jobs 1955-2011

[mark at buttery.org (Shirley Márquez Dúlcey)]

On 10/8/2011 11:42 AM, Rich Braun wrote:
> Jerry Feldman mentioned an old computer:
>> My first home computer was an Apple II (1978). What Jobs saw back
>> then was that a desktop computer could be useful to real people.
>> At the time, there were a few hobby computers. I almost bought a
>> MITS Altair
>
> The first desktop I ever ran across was in my math teacher's class in
> Arlington, VA in 1977:  an HP 9830A (you can find pics of it via Google).
> Anyone else remember those?  It had 4K of RAM, kept your programs on a
> cassette tape, printed out (quickly) on an 80-column wide thermal printer.
> You programmed it in BASIC; I remember writing a banner printing program and a
> biorhythm chart generator.
>
> Being exposed to bigger mainframe computers starting around '72, I never
> thought of these micro things as anything other than toys.  So when the TRS-80
> and Apple ][ came out, they held little interest for me--my first
> factory-built (i.e. not cobbled-together) home computer was a 1982 DEC surplus
> PDT-11/150; it ran RT-11.  The first "real" home computer, that rivaled
> mainframe performance, came along about 10 years later:  the Intel 486.
> That's when speed-of-light constraints came to favor microchips over the
> "frames" containing CPUs in multiple circuit boards spread across a backplane,
> and transistor density has accelerated ever since.
>
> By the time of the 486, Linux was available: today's supercomputing clusters
> usually run Linux.
>
> -rich

The first computer I had any personal experience with was an IBM 1620. 
20K of BCD digits, and the peak instruction rate was about 6,000 per 
second. (The memory cycle was 20 microseconds and the shortest 
instructions took eight cycles.) Oh, and a hard disk that stored 2M of 
BCD digits.

After a year my school replaced it with an IBM 1130, which was hardly a 
powerhouse either: 8K bytes of RAM and a peak execution rate of perhaps 
80,000 instructions/second (5.85 microsecond cycle time and most 
instructions took multiple cycles). Oh yes, another hard disk; this one 
stored one megabyte and used stepper motors that made a loud saw-like 
noise during seeks. Although it was a hard disk it was no faster than a 
floppy drive.

I did have some exposure to more powerful systems at the nearby state 
university. They had a midrange 370 system (370/155 if memory serves) 
that was used in batch mode (submit deck of cards, come back later for 
printouts) and a PDP-10 timesharing system with ASR-35 terminals.

Once home computers had floppy drives they were already exceeding the 
performance of the 1620 and 1130 (though the early floppies didn't have 
as much capacity as the hard disks did) so they were never toys to me. 
It was a while before I could scrape up the cash to buy one of my own (I 
had an SWTPC 6800 kit that I never quite got to work properly, and later 
an Atari 800XL) but I certainly wanted a home computer right away!