20220627: ELIZA Game by Zachtronics

I came across this interesting game based on ELIZA, by Zachtronics, a semi-defunct boutique game company: "Eliza is a visual novel about an AI counseling program, the people who develop it, and the people who use it."

20220529: An analysis of the FAP HASH function (Anthony Hay)

Anthony Hay has done some further analysis on the FAP HASH function, which is used in ELIZA's memory.

20220519: 1975 LISP ELIZA (Contrib. Lori Levin, author unkown)

Lori Levin has contributed a 1975 Lisp ELIZA from The University of Pennsylvania Moore School of Electrical Engineering. Interestingly, this ELIZA has the script programmed into the code, as opposed to most earlier ELIZAs that read a script. (Ed. note: Lori notes that she didn't write this code. We aren't sure who did, but this is very likely the ELIZA that I remember seeing as a Penn undergrad, as I knew Lori then, but this was well after I'd written my BASIC version, in 1973. -- Jeff)

20220519: ELIZA Scriptwriter's Manual (Computer History Museum)

The Computer History Museum has generously created a PDF of The 1968 ELIZA Scriptwriter's Manual, by Paul R. Hayward. This document helps to fill out a little-known branch in the genealogy of ELIZA which, soon after it was initially created (in 1965), teachers at MIT, esp. Dr. Hayward, sought to apply it in education. The relevant CHM archive entry is here: https://www.computerhistory.org/collections/catalog/102683842. Interestingly, the version of ELIZA described in this document is greatly extended from the original, including what appears to be a MAD-SLIP interpreter built into the ELIZA scripting language.

20210329: As Close an Eliza as One Can Get (Anthony Hay)

Anthony Hay <anthony.hay.1@gmail.com> writes:

This is an implementation in C++ of ELIZA that attempts to be as close to the original as possible. It was made to closely follow Joseph Weizenbaum’s description of his program given in his January 1966 Communications of the ACM paper. It is controlled by a script identical to the one given in the appendix to that paper. When given the prompts that begin “Men are all alike” it gives back the identical responses and recreates the exact conversation from the paper.

I was interested to read that Prof. Millican thinks Weizenbaum “cheated” in order to obtain the conversation shown in his paper. The response in question was “DOES THAT HAVE ANYTHING TO DO WITH THE FACT THAT YOUR…,” which is the last entry in the MEMORY section of the script, rather than the first. But Weizenbaum’s paper says that “…one of the transformations on the MEMORY list is randomly selected…,” so I don’t think it unreasonable to think that the last entry could have been randomly selected on this occasion.


20200809: Elizabeth an Eliza with an easy-to-understand script notation (Peter Millican)

Peter Millican <peter.millican@hertford.ox.ac.uk> writes:

I’m a Philosophy professor at Oxford, who’s spent most of my working life on the boundary with Computer Science and trying to encourage students into that space. Trying to get Humanities students interested through LISP programs is hopeless, of course, so when teaching Computing and Philosophy at Leeds, I developed a chatbot designer system called Elizabeth which is programmable using an easy-to-understand script notation. You can find the latest version at http://www.philocomp.net/ai/elizabeth.htm, and learning materials at http://www.philocomp.net/ai/elizlearn.htm. One of the built-in Illustrative Scripts is transcribed from Weizenbaum’s original paper of 1966. If you look at the second video on http://www.philocomp.net/videos/turing.htm, from 18:30, you can see me going through the dialogue in an online talk (part of whose point was to prepare the students for using Elizabeth in an exercise by seeing the sorts of tricks that can be done). As far as I know, this is the only system that allows non-specialist users to work through the operation of ELIZA, seeing a trace of all its internal processing, and I believe that it faithfully copies the behaviour of the original program as published, with just one exception …

One interesting point that I mention in my talk, but have never seen mentioned by anyone else, is that Weizenbaum’s published dialogue doesn’t actually fit with his published program: one of the responses is out of order (though this can easily be fixed by swapping two of them round, as I do in my script transcription). I take this as evidence that Weizenbaum “cheated” to make his dialogue appear as impressive as possible, and then probably forgot or didn’t bother to change the program accordingly. Have you ever seen a mention of this point? Is it actually well-known?

Peter Millican
Gilbert Ryle Fellow and Professor of Philosophy
Hertford College, University of Oxford
Faculties of Computer Science and Philosophy

A bit more about the problem that Peter discovered in the scripts (from a subsequent email exchange):

I talk about the "cheat" from around 24:25 to 26:00 in the video.

In the script file "Weizenbaum.txt" the matter is annotated like this:

/ ***** No-keyword responses involving "MY" memories *****
/ Order changed to conform with published dialogue:

Here "N" signifies a "no-keyword" response, while [M+1] picks up the first stored memory (ELIZA only stores "my …" memories, so there's no need for more sophisticated memory management here). "&{M+1\}" then specifies an action to be performed when this response has been triggered - it deletes the first stored memory (which, of course, has just at that point been used).

For comparison, the relevant snippet from Weizenbaum's SLIP program in his article is like this:


(0 YOUR 0 = BUT YOUR 3)

Notice that the "DOES THAT HAVE ANYTHING TO DO..." response is last of the four in this group, whereas for the dialogue to work, it needs to be first.

In every other case, my script follows the relevant orderings from Weizenbaum's article, so this is very much a special case!

20190215: Eliza in gnuCOBOL (Arnold J. Trembley)

This amazing Eliza in gnuCOBOL was written by Arnold J. Trembley. It's a slightly indirect translation of Shrager's 1973/1977 BASIC version. The most amazing part of this (to me) is that it was written in 2017!

Mr. Trembley writes:

I also have a link on my website for an executable download for Eliza in GnuCOBOL that runs on Windows 7 and higher. I think it would probably run on Windows XP too.

I probably first saw ELIZA in BASIC from Ahl's computer games for BASIC book, but I also wrote a version in 1974 ANSI-standard COBOL for an IBM Series/1 Minicomputer way back around 1984. But I never saved that source code, so I had to start all over when I converted it into GnuCOBOL.

Getting Eliza to work was a lot of fun.

20190121: Eliza on ITS on a DEC 10 Emulator (Lars Brinkhoff)

A few days ago I had the pleasure of taking a trip in a real live time machine.

About a week ago I got an out-of-the-blue message from Lars Brinkhoff via the ElizaGen issue tracker: "I have a version of ELIZA ported to Maclisp, dated 1977-09-05. Unfortunately, it's just a compiled binary file. Is this of any interest to you?"

Just a binary wouldn't be too interesting, so my initial reaction was muted: "Is there any way to either run it, or extract the embedded code?"

Turns out that Lars had significantly understated the situation: "The binary file is a compiled FASL, fast load file, so it's not easy to extract any code other than PDP-10 instructions. It might be possible, but a lot of work, to reconstruct Lisp code that compiles to approximately the same FASL code."

However, went on: "...we can run it in Maclisp running on a PDP-10 emulator. I have an emulator online."

Eliza on MacLisp on a PDP-10 emulator? Isn't there a level missing here? On what OS?

The answer gave me pause: MIT's ITS. ITS is one of the most important operating systems in CS history. (Among many other interesting historical facts, the original EMACS was developed on ITS!) I recommend reading about it here: ITS on Wikipedia. When I was an undergrad and grad student, in the late '70s and early '80s, we used MIT-AI's ITS remotely through the early ARPANet. Interestingly, at one point (I don't know for how long) the ITS at MIT-AI had an Eliza hacked into its command line driver so that unless you prefixed your commands with a ":", the response was from Eliza!

Eliza on MacLisp on ITS on a Dec 10 emulator? Really?!

Yeah, really!!

Here's the emulator: https://github.com/PDP-10/its

(Lars notes: "...there are more people involved than me. Foremost Eric Swenson who worked on Maclisp and Macsyma back in the day. We [...] update the emulators to support more hardware, fixing bugs, figuring out how to build and run programs, adding new software, Etc.")

If you want to play with a great piece of software history, you can log into this ITS emulator yourself; It's free and open. No password required!

From Lars:

Telnet to "its.pdp10.se, port 10003". Type Control-Z to log in. Then ":lisp games; eliza (init)" to start Maclisp and load ELIZA. It should look something like this:



telnet its.pdp10.se 10003

Connected to pdp10.se.
Escape character is '^]'.

Connected to the KA-10 simulator MTY device, line 4


type Control-Z

TT ITS.1648. DDT.1546.
TTY 25
2. Lusers, Fair Share = 0%

For brief information, type ?
For a list of colon commands, type :? and press Enter.
For the full info system, type :INFO and Enter.

The management apologizes for the use of the slow TK10 terminal
multiplexer. We'll upgrade to the much faster Datapoint kludge once
it becomes available.

Then you type:

:lisp games; eliza (init)

(Please Log In)

Et voila. you're typing back through 40+ years of computer history!

(Use double ENTERs to terminate your sentence to Eliza.)


To test it, I pasted the "standard" example conversation from Wiezenbaum's Eliza paper. Here's a screenshot from the paper:

And here it is, running live on Lars's reborn ITS (the mess at the bottom is because I accidentally pasted the sentence twice, and had to backspace over it. The repeated chars are apparently how ITS displays backspacing):

There's a bit of a mystery about where exactly this version came form. Lars and I theorize that since BBN was right across from the AI lab, and it's known that BBN were users of the ITS systems, this may well be Bernie Cosell's original code!

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20181031: "Hello, I'm Eliza" (Stefan Holtgen and Marianna Baranovska)

20181031: Stefan Holtgen and Marianna Baranovska have just published a volume entitled: "Hello, I'm Eliza", with Computer Archaeologie.

Here is the abstract (rendered from the German by Google xlate):

The contributions to this volume are partly based on a conference held in October 2016 at the Institute of Musicology and Media Studies, and bring together authors from the fields of computer science, philosophy, media studies and media dramaturgy. In the individual chapters, the origins of the first chatbot ELIZA, which Joseph Weizenbaum developed at MIT's AI Lab in 1966, are reconstructed, Weizenbaum's programming language SLIP is presented and a first German-language translation of his publication to ELIZA is presented. As an extension of the topic, the authors ask what influence ELIZA had on computer culture, AI research, cultural criticism of the computer and art.

And here's the interesting cover. (Note that the code in the background is a part of Shrager's 1973/1977 BASIC Eliza)

20180529: B5500 Eliza from 1971 (Peter De Wachter)

20180529: Peter De Wachter found a very interesting version of an Eliza clone from c.1971 (!!) Peter writes: "The B5500 emulation project has imaged a bunch of old tapes and they found (among much other software) a 1971 Eliza implementation by Charles Fricks and John Covert from Georgia Tech."

The full story is here:


The Eliza source code is here:



What makes this so interesting is that the implementation language is "Georgia Tech Language" (?), which seems to be an Algol extended with Lisp primitives. The resulting code looks like this:










(Ed. (Jeff S) notes: CDADADR !!)

20171211: BASIC Eliza via Speech Synthesis (Michael Wessel)

20171211: My friend and colleague, Michael Wessel, who apparently has a soft spot for ancient speech synthesizers, recently noted this curious coincidence/historical anecdote about a German version of my BASIC Eliza. (Michael and I worked together on the AURA project at SRI for about a year around 2013.)

Michael writes:

"About 1985 I typed in a version of your BASIC Eliza from a public library copy of the 'Creative Computing Computer Games' book, into my Amstrad CPC 464 home computer. The book had been translated into German, and so was Eliza! I wish the editors hadn't done so, as it makes much less sense!

Back then I owned a speech synthesizer (the Amstrad SSA-1 for the CPC), and I had extended your BASIC Eliza with speech capabilities. The audio/speech quality was as awful as some of the TRS 80 speech synths you can hear on YouTube.

Now, 32 years later or so I am working on a little spare time hobby project - a modern, understandable speech synthesizer for the Amstrad CPC, which is designed to be compatible with that original "retro" Amstrad SSA-1 speech synthesizer. And indeed, the old Eliza that got extended with SSA-1 speech output is working well with my modern speech synthesizer."

Here's a youtube video of Michael's German-speaking Eliza.

And here is another version for the CPC, also with speech output.

Michael continues:

"With respect to the second video (the English one), the original author of this Eliza version also mentions your Eliza as the source for the program, but he says he extended it significantly, and then I added speech output, this time using the 'native mode' of my speech synthesizer, which gives much better speech quality than the emulated 'retro SSA-1' compatibility mode, as you can hear."

As I mentioned above, Michael and I worked closely together at SRI for about a year. He concluded his note this way: "It's really a funny and strange coincidence that our ways have crossed; What are the chances that you get to work with someone whose BASIC program you typed in from a public library book 30 years ago? Sometimes, the world is small!"

I couldn't agree more!

Here's the disk image of Michael's German BASIC Eliza:


To run it:

  • Download extract the DSK image

  • Go to: http://cpcbox.com, which is a CPC Emulator in Javascript running in the Browser

  • Select "Choose configuration -> 464"

  • Select the Eliza DSK file for "DRIVE A:"

  • When the CPC boots up, enter "cat"; You should see "ELISA-NS.BAS"

  • Enter: RUN "ELISA-NS (Without Speech ("NS = no speech")
    (The other version is with speech, but doesn't work on the emulator)

Here are some PS2 Screenshots from emulator running in Firefox:

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Aggregated Older News

20170728: Through the efforts of Dave Walden and Bernie Cosell, the tapes and listings of Bernie's original Lisp version of Eliza/Doctor have been accepted into the Computer History Museum archives as lot number: X8258.2017.

20170307: Jeffrey Perrone pointed out this hysterical video of Eliza talking to Eliza on two side-by-side Google Home systems!

20151122: John D. writes (email to Jeff Shrager of 2015-11-22): "Back in 1979, Radio Shack released their own commercial version of Eliza for their TRS-80 Model I, sold in their stores. It was written in machine language, not Basic, on cassette tape. In fact, the tape had two versions: a regular one, and a special version that gave Eliza's response through the expensive Voice Synthesizer they were selling (a Votrax derivative)."

"The interesting thing about Radio Shack's version is that it seemed a bit more sophisticated than the original Weizenbaum version. It recognized more words. (Including swear words--just so it could react with 'There's no need for that language.'-- which is weird to see inside a mass-market product sold by a major corporation!) And when you said "Goodbye" it gave you a diagnosis: everything from "You have no psychological problems besides a normal amount of paranoia" to 'I must conclude you are dangerously psychotic and should be locked up'!"

"It was apparently written by Device Oriented Games in Dallas (near where Radio Shack was based)."

Links to runnable code:

John also found this YouTube video of a real TRS-80 with the Voice Synthesizer, running Talking Eliza. The Votrax quality is terrible, but that makes it all the more fun!

20151013: Paco Willers has written a GO version of the classic BASIC Eliza. In the process he did a detailed, nearly line-by-line, deconstruction of the Shrager/North 1973/1977 BASIC code.

20150910: Melody Ayres-Griffiths (melody@planetirata.com) found this completely wacko version written by Dave Babcock in Integer BASIC, which uses computed gotos! It looks to my eye like someone took the Shrager/North version and stuck it in a blender. :-) It would be easier to generate this from a compiler, than to write it out straight!

20150105: James Markevitch has updated his 1966 version with a slightly cleaned up transcript, and his amazing PERL BBN Lisp Interepreter! I've uploaded everything to the github site, and it is all also available for download as a tarball here.