elizagen.org/1966_Cosell_BBNLISP/ptape

Paper tape images of the "doctor" program (aka Eliza) in BBN PDP-1 LISP.

README		This file
doctor.ptape	Paper tape labeled "DOCTOR  10 JULY"
doctor.ascii	doctor.ptape converted from FIO-DEC to ASCII
scrip.ptape	Paper tape labeled "SCRIP 4.1  2 July 1966"
scrip.ascii	scrip.ptape converted from FIO-DEC to ASCII
bbnlisp.pl	BBN-LISP emulator written in Perl
bbnlib66.lisp	Function library for BBN-LISP
session		Transcript of a run on a BBN LISP emulator

The paper tapes are encoded in a (modified?) FIO-DEC encoding for the
PDP-1 computer.

FIO-DEC is an odd parity encoding of PDP-1 "concise code" (with a few
additional characters).  The MSB is the parity bit.  Concise code is
a six-bit code with "upper case" and "lower case" characters that are
seleced with "shift" codes to switch between upper case and lower case.

Concise code was converted to ASCII based on the conversion table described
in F-15D, PDP-1 Handbook, October 1963.  Some of the concise codes contained
in the paper tapes do not have an ASCII equivalent.  These were represented
using the following:

Upper case octal 05 (or)	!	Same representation used by simh
Lower case octal 40 (dot)	@	Same representation used by simh
Octal 75 (back space)		BS
Lower case octal 14		L14
Lower case octal 32		L32

The program can be run under the emulator using the following command line:

   bbnlisp.pl -doctor66 -load bbnlib66.lisp -load doctor.ascii -load scrip.ascii

Then type (doctor) at the prompt.

James Markevitch
December, 2014