Ancient Computing Machinery

«Those who scorn computer history are those who really don't grasp what is happening today and will never really shape tomorrow.»
-Don Congdon

1. that the simulation be a reasonable facsimile of the original;
2. that it embody the complete functionality of the original;
3. that it have a teaching-mode built-in.

• John Bradley (who also wrote the excellent xv) already wrote a simulation of the slide-rule; it was part of the R3 version of xcalc, but was removed in subsequent releases.

• You can download a PostScript file that renders a slide-rule which can then be cut and pasted together to obtain a working sliderule.

• Sliderule Home Page

• The 50th anniversary of the ENIAC.
• Calculating Machines

Here are some ancient computers

(48K) IBM Selective Sequence Electronic Calculator from 1948. This system had three levels of memory: electronic, relay, paper tape.
(Left side) The first cabinet contains card reading tubes. The second contains sequence tubes. The next four contain sequence relays. The first gentleman is standing in front of the table look-up.
The three large circular objects in the back are spools of 80 column paper tape. Each spool is feed into a punch unit and into three separate tape readers.
(Right side) Arithmetical unit, pulse generator, sequence interlocks, electronic memory.

(30K) DEC PDP1

(17K) DEC PDP1 front-panel closeup.

(31K) DEC PDP6

(30K) LGP-30, manufactured by Librascope in about 1960. It has been described as the minicomputer of the vacuum tube era. The machine is imortalized in the story of Mel, a "real" computer programmer, as retold in _The New Hackers Dictionary_.

(18K) PDP1 display with a spacewar game in progress.