What are some games that never redraw the screen—only draw additively—and can be represented as text or ASCII art?

This is the class of games that can be played on a teletype, besides the obvious text adventures. With reverse line feed like the Teletype Model 37, a game board can be filled in, play by play.

* Minesweeper
* Picross
* Sudoku
* Voltorb Flip
* crossword
* regular expression crossword
* virus war / Paper Tactics
* tic-tac-toe
* hangman

#retrocomputing #retrogaming #teletype

Whew! I just finished porting 2,852 lines of PDP-11 assembly to C by hand over the past week!

This is for form/fed, a form letter editor and generator with template substitutions, introduced in 1971. It's the largest UNIX utility that was never ported to C, and has since been forgotten.

1/6

#unix #retrocomputing #vintagecomputing #reverseengineering

I like finding and fixing bugs in 52-year-old software, especially when all later versions retain the bug.

#unix #vintagecomputing #retrocomputing

RIP Margaret Hamilton

#nasa #vintagecomputing #retrocomputing

Margaret Hamilton, computing pioneer who led the software behind the Apollo program, passed away last week. She advocated for high-assurance software and introduced the term software engineering.

https://news.mit.edu/2026/margaret-hamilton-computing-pioneer-dies-1007

#nasa #vintagecomputing #retrocomputing #apollo

I'm the lowest tech high tech person in the department.

My desk is covered in binders of papers I've read, neat books, paper tapes, a yellow Utah teapot, sticky notes, 5.25" floppies to image, a text telephone, etc. The table over has UNIX V4 on my PiDP-11, Silent 707/1200, and VT220, with lots of printed terminal sessions and a stack of ed manuals.

As a side effect, I get a pass for using my brain, instead of AI.

When I read UNIX-HATERS a few years ago, it unexpectedly helped me fill a gap in regular expression history.

In its chapter on Usenet, they complain about Larry Wall's rn newsreader. It introduced killfiles, which filter emails using regular expressions.

Well, I had incidentally just been researching historical regular expression engines and trying to trace back the development of regular expressions in Perl 1.0. Since Larry Wall created both, it seemed likely that rn influenced Perl. It turned out that Perl adapted the engine from rn and ultimately from James Gosling's Emacs. Since Perl removed attribution comments, I don't think this had been established before.

When I revisit that project, I'll need to update it for what I learned from chatting with James Gosling at SIGGRAPH.

https://github.com/thaliaarchi/regexp-museum/blob/main/viewers/rn.md

#unix #vintagecomputing #retrocomputing

For context, this is a draft copy of The UNIX-HATERS Handbook from two years before publication. It was presumably sent to Jay Lepreau for feedback and I think this is the only surviving copy. Jay worked with UNIX throughout his career and it was found among his papers, along with the UNIX V4 tape. I will be scanning it.

Personally, I found the book to be quite a fun read. It's a bunch of sore losers to UNIX's success. The anti-forward by Dennis Ritchie is a treat.

https://web.mit.edu/~simsong/www/ugh.pdf

I hate UNIX.

#unix #vintagecomputing #retrocomputing

I'm hopeless. This teletype in North Carolina has got me arranging to pick up teletypes in Michigan and Chicago too and play with a PDP-8 in Iowa. But I tried chasing that Nebraska lead to no avail and the PDP-11/23 might have fallen through. Even still, this will be an eventful roadtrip!

Magneto-optical data recovery is going well so far! Watching The Next Generation while each 622.1 MiB side is imaged.

#retrocomputing #vintagecomputing

Dig Dug at the local arcade is now filled out with my high scores. I’ve still got it.

Might be getting a PDP-11/23 soon!!! :)

Do you know anyone in Nebraska who worked for Union Pacific in the '70s–90s or is a ham radio or vintage computing enthusiast? I'm following leads on Teletype equipment used there.

Boosts appreciated.

#vintagecomputing #retrocomputing #teletype

I just acquired a Teletype Model 37 reperforator-transmitter! I've been trying to track down a Model 37 for two years now, hitting many dead ends.

Well, this is the paper tape reader/punch that would connect with a regular Model 37 KSR, so it's not the same thing. But I've been wanting to be able to work with paper tape, so it's still quite exciting. I had never seen such a reperforator before, until I was asked for details on it.

I'll be hauling it from North Carolina next month and would love to visit vintage computing people. I'm planning on stopping in Chicago and central Nebraska.

#vintagecomputing #retrocomputing #teletype

It works!

#unix #retrocomputing

A cursed way to dereference a constant address without casting it to a pointer (C didn't have casts yet):

struct { int int; };
#define PS 0177776

PS->int = sps;

https://www.tuhs.org/cgi-bin/utree.pl?file=V4/usr/sys/dmr/tty.c

#unix #c #retrocomputing

Just modified the UNIX V4 kernel and utilities so it supports backspace for deleting characters. Pressing backspace instead of # was the top mistake made by LRC attendees, so this would make it easier to use for modern users.

The erase (delete last character) and kill (clear current line) characters were fixed to # and @, inherited from Multics, and not made configurable until a few months later around November 1974. Perhaps this change reflects the first time a video terminal was used for UNIX.

I made it send BS SP BS when backspace is pressed to visually clear the character, but this unfortunately makes it clear commands' output too. For example, this lets you visually clear the shell prompt. I could fix this by implementing something like curses, but that would move the logic to user space and incur overhead for swapping the process for a context switch on every character press. This was a complaint of early vi. Maybe I could track the column of the last printed text and not let you visually backspace before that?

#unix #retrocomputing

I fixed a little bug in UNIX V4 that had been bugging me. It took a terminal session of 5596 lines, including all the code I read, to arrive at a 4-line fix. Imagine all the paper.

https://github.com/thaliaarchi/unix-v4-demo/commit/33f294afb9cb48cda9ddbcb159d947d94c4eddd3

#unix #retrocomputing #vintagecomputing

LRC 2026