Got a question....PDP? VAX?

From: Lawrence Walker <lwalker_at_mail.interlog.com>
Date: Fri Mar 12 19:25:47 1999

On 12 Mar 99 at 17:53, Mike Ford wrote:

> >Hi!
> >
> >I've been growing up in the age of "IBM era" of computers. The only non-IBM
> >(compatible) computers that I've worked on was an apple //c and a TRS-80
> >model III that nearly caught my basement on fire. I'm 16 years old, so I
> >haven't had any experience with any pre 1980's stuff (other than the //c).
> >
> >What I'm wondering, is what exactly is a PDP, or a VAX, or an Altair, or any
> >of the other things that come up frequently on the list. Also - how is one
> >of the computers (such as the Altair) operated, with all the switches and
> >indicators? Is there a keyboard or a monitor with it?
>
> Wow, do you want the one or two paragraph history of computing as we know it?
>
> Maybe Moore's law explains it best, every couple of years computers get
> twice as fast, for half the money and size. Now Start with a typical
> present day Pentibum II 400 Mhz 128 MB ram 10 GB hard drive that sells for
> $2000 and go back in time 20 years (about 10 of Moore's cycles). Computers
> were 1000 times slower, bigger, and more expensive. That was a different
> world, and you had to treat such valuable resources differently. People,
> and really only a small favored few, had to share the computers, and time
> 24 hours a day was highly prized.
>
> Around 1970 a computer about as powerfull as a present day $100 calculator
> cost about $10 million and required a large secure and temperature
> controlled room. That was the mainstream of mainframe computers. The
> computer was the size of a kids play house, and all around it in the large
> room were "peripherals" designed to keep the main cpu busy working all the
> time.
>
> Away from the main IBM oriented data processing shops, dozens of smaller
> companies fought for the minicomputer market. Smaller, and less powerfull
> in absolute terms, these units were targeted at the scientific and
> industrial users who needed the computational or control that only
> computers allowed. Minicomputers weren't that different from mainframes,
> just scaled down in some senses, and optimized in others.
>
> Digital Equipment Corporation, DEC was one of these minicomputer companies,
> and its PDP line was hugely popular in many areas. Industry, banking,
> telephone, and most important universities. The DEC PDP series became the
> platform that many computer scientists experiemented on, and many students
> still didn't get to use. As Moores law improved the lot, the VAX line came
> out, and people logged on with gusto forever after.
>
> Oh, those switches and lights are mostly because the hardware and software
> used to screw up fairly often, and by looking at the lights, and flipping
> switches the operation of the computer could be single stepped (one
> instruction per button push) and errors identified so they could be
> corrected.
>
 Wow, great thread. Thanks Jason.

 I tend to think of the evolution of computers in physical relation to myself.
 
In an incarnation in the mid-fifties, I worked for a large government
department as a "junior IBM operator" I worked sorting IBM cards, reproducing
cards that were "bent, mutillated, and spindalled", and wired peg-boards to
interpret the data contained on those cards, which were "punched" by a
room-full of typist "punch-card operators". Even tho this was a large gov.
apparatus, the machines could only be "leased" not bought from IBM and
even some programs were rented. In a temperature-controlled room
filled with machines spinning large metal tape-reels were the "high priests"
of this genre. I never entered that room. It had windows where you could see
the esoteric operatives at work.
 In the 70's I worked for a large railway keeping track of boxcars entering and
leaving the Yard. I would write up a report each day and submit it to the
computer room. Again, a temperature and environment controlled room, but
the "priests" were fellow workers who, tho aloof, I could talk to. And I could
even enter the "temple"
 Fast forward to the early eighties in a tech school.
Each student had a terminal ID to access the main computers but they were
at another location which I never saw. The school could even have been renting
service space from another provider. But in the course I actually used a real
computer more or less, an ET3400, to explore the godlike ways. We also had
a trainer in which you could enter and step thru each program using switches
with LED indicators. In a tech-course a few years later I was introduced to
floppydisks using an Osbourne. We smoked and drank cokes using them.
 To me the great flowering of the 8-bits was the demystifying of computer
arts. Unfortunately, I feel OS2, Win9x, and NT are removing us from
that control ,as against the "high Priests" of VAX. It's amusing to
remember that my professors looked blank when I asked them about Unix
in 83 after reading about it in "Electronics" magazine. I explained it as
simply a method of disk storage organisation and access.
 Altho the computer world has changed mightily I think the "deification"
remains with the minis and mainframes and Unix is it's theology. I
appreciate Linux precisely because it has an empowering feel to it.
That is the glory of the personal computer.
 I have a PDP-8 maintenance manual and an IBM VS360/370 programmers
manual and at some point I will study them. But neither can give me the joy of
an old "populist" 8-bit programming manual, with a code-bloatless program to
automate your toaster on a 64k ram machine. That was elegance.
 Flame away.

ciao larry
lwalker_at_interlog.com
Received on Fri Mar 12 1999 - 19:25:47 GMT