DPRG mailing list archives: [DPRG] Re: Anyone have an Old PC they want to give away?

Tue Jul 30 06:30:01 CDT 2002

So you really miss them Hollerith cards huh?
At one long gone business I worked at, we had a old General Automation
Spc-16 which we programmed in Fortran, using punch cards. We only had two
punch card machines, one machine punched the holes (bits?) when you pressed
a key. If you made a typo, eject and try again. Everyone fought over the
other punch card machine, as you could type in the whole libe and then punch
it all at once.
On the rare occassions when we had to use machine language you would use
paper tape to load your program into the computer. When I first started
there the SPC-16 had two hard disks, 2meg fixed and two meg removable on 14
inch platters. They upgraded it to 5meg fixed and 5meg removeable and then.
I sorta miss that SPC-16, it was great, it had 128k words of magnetic core
memory, you only rarely had to use paper tape to reload the primitive OS to
get it going again. It had a 8 mhz clock too! But the neat part was the
front panel, it had my favorite collection of illuminated paddle switches
and indicator lights. You would manually enter the machine language code in
on the paddle switches and push the load and increment button to move to the
next memory location and repeat. Just like the old RCA-1802 dev kit I have
someplace. We only had to do this if you really crashed the computer and had
to reload the paper tape loader program to read in the OS from paper tape
again. Which would then get you back up to reading in the rest of the system
>from the fixed HD platter on the machine. The SPC-16 was a full height rack
mount machine, you had to stand on a stepladder to reach the removeable
platter cartridge if you needed to change it. We also had two teletype
machines and a huge line printer along with a primitive 4 line by 20 char
CRT terminal hooked up to it (it actually looked pretty modern with it's art
deco styling).

When I was in the Marines, back in the prehistoric times, I used to work on
this really neat 3D rangefinding and tracking radar system. It used 26,000
vaccumm tubes. Guess what, it used paper tape to load programs too. It used
to work with only 90% of the tubes functioning too. I don't think I ever
remember it as having all tubes functioning, as there was always one out
someplace in the guts of that sucker. Beleive it or not but they considered
this a portable radar system, you used sixteen 6 ply trucks to move it.
Before you put it up, you would level a spot and pour quick set concrete
with the mounts imbedded in the concrete. After the concrete got hard you
would start to setup the radar, but before you raised the dish you would
erect this huge inflatable dome, and then raise the dish. The dish was very
sensitive to wind. It had a little red light on top that you could turn on
so aircraft wouldn't hit it at night, and if the air pressure was a little
low it would sag just right and look like a "you know what".

I never got to work on it (too old for even me) but the British had the
neatest computer way back in 1948, with a computer that had 256 words of
memory using DEKATRON tubes. It had a 20khz clock too. That was one of the
first examples of a programming loop. They took a paper tape program and
glued the two ends together and viola!! you had a loop. Now this thing was
pretty big, it took up about 1/2 of a modern house's garage too. DEKATRON
tubes came out before Nixie tubes were invented, they were used as
indicators and also as early memory store devices and counters (similar to a
shift registor or flip flop device). You could use Dekatron tubes to add
subtract, multiply and divide and display the result too.

David wrote:
I've still got my first computer, back in the days when the bits were
so big you could SEE THEM with the naked eye!  God's truth! Carried them
around in stacks, we did. And all the programming was done with diodes and
a soldering iron. Steam powered at that.  Whole thing was spec'd in FLOPS
Per Fortnight. Up to as many as one task, simulataneously!  Bits were so
big we had to sweep them up off the floor at the end of the day, walked
ten miles barefoot in the snow every morning to school after milking the
chickens at 4am, and all I ever had to play with was an old rag!

And we LIKED IT that way!!!  No wussy windows or operating systems then!

All we had were ones and zeros, sometimes not even ones, most of us had to
make do with lower-case "L."  We were so poor we didn't even have ones. Once
wrote an entire database with just zeros.  (stole that line from Dilbert).

Dag nab kids these days have no concept.... hurrumph harrumph!!!!

Ever noticed how much smaller the bits are these days?  And another thing,
the speed of light ain't what it used to be, and a nanosecond is starting
to seem pretty dang slow.  Light travels about a foot in a nanosecond,
can't even make it from one end of the CPU board to the other.  ('course
light was a lot faster back then.)

And while we're on the subject, this club needs a few more contests!!!
One for each day of the year, extras for leap year!!  Two on holidays!!

And another thing!! Don't stand there with the refrigerator door open!
and stop tracking mud all over my nice clean floor.  And don't pick you
nose!!

ok, time for my medicine...

Ahh, that's better. where was I?

Oh yeah. Been reading the documentation for the newmicros IsoPod board.
Pretty nifty robot controller, folks.. Built in hardare PWM, 12 channels
of servos, hardware quadrature encoder decoding, two 4-channel 12 bit A/D
(12 bits!!) Built in Forth language and extensions for Augmented Finite
State Machine (read: subsumption) which is pretty much how all my robot
code works anyway for SR04, Legobot, and the ever-balancing nbot:   $99.
Pretty nifty.

sleep well,
dpa

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