Bell Labs CARDIAC found!

From: Ethan Dicks <erd_at_infinet.com>
Date: Tue Aug 18 13:35:15 1998

To all fans of that ancient computer learning tool, the Bell Labs CARDIAC, I
have finally succeded in my quest thanks to a generous tip from someone whose
name has been lost in my overloaded home directory.

The company that got the distribution rights to Bell Labs educational
products is...

        Comspace Corp.
        243 Dixon Ave.
        Amityville, NY 11701

        1.516.789.0700 (v)
        1.516.789.0890 (f)

The CARDIAC is $14.95 plus $5 S&H/Ins in the U.S. Apparently, quantity
discounts are available, but why you'd need more than one or two (one
to scribble on, one to keep pristine), I don't know, unless you have lots
of geeky nieces and nephews.

The CARDIAC itself comes as a tri-folded piece of die-cut cardboard that
unfolds to larger than 11"x17". 2/3 of it are the main body, the last
1/3 is the moving parts - slides for the accumulator, the op code and
two address digits. The ladybugs that someone mentioned are the shape of
a tennis racket - the shaft goes in a hole corresponding to the current
program counter, the ladybug sticks out like a flag.

Assembly looks pretty straightforward. Punch. Fold. Glue. At first
glance the programming reminds me of a BCD PDP-8. There are 10 opcodes:

        0 INP Input
        1 CLA Clear and Add
        2 ADD Add
        3 TAC Test Accumulator contents
        4 SFT Shift
        5 OUT Output
        6 STO Store
        7 SUB Subtract
        8 JMP Jump
        9 HRS Halt and Reset

Each of the 100 storage cells hold a three digit number - an opcode and
two digit BCD operand, or three digit data. The "first program" looks
like this...

  17 034 Read "A"
  18 035 Read "B"
  19 134 Clear accumulator and add A
  20 235 Add B ("S" is not in accumulator)
  21 636 Store S
  22 536 Print S
  23 900 Halt and reset

To "run" the program, you write in the numbers in the appropriate cells,
write the two numbers to be added on an input strip, stick the bug in
cell 17, and stick a blank "output" card in the output slot, then follow
the flow diagram printed on the front of the CARDIAC. Towards the end of the
booklet, the programming gets more and more complicated until CARDIAC
can play NIM.

I'm glad I finally tracked one down. I can see how many people remember
it fondly (my own early experiences were with the Digicomp which is not
so easy to find. I'd *gladly* pay $20 for one of those, even broken).

In addition to the CARDIAC, Comspace also has other educational aids and
books that were an outgrowth of Bell Labs science educational programs.
When you call, tell them Ethan sent you.

-ethan
Received on Tue Aug 18 1998 - 13:35:15 BST

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