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larsbrinkhoffon Brief History of PDP Computers

Hi Don!

The AI PDP-6 and 10 shared a Type 340 between them. It was the only 340 in the lab. Lick's Dynamic Modeling group had an LDS-1 from Evans&Sutherland.

LLOGO could display vector graphics on the 340 or GT40, and raster on the Knight TV or LOGO color TV (16 colors!)

LOGO versions on ITS include BBN LOGO for TOPS-10, CLOGO for ITS, LLOGO, 11LOGO, and Apple II LOGO. Yes, 11LOGO is recovered. There's an early standalone version, and a later version that ran on the SITS timesharing system on an 11/45.

Yes, there are GREN files. I have been in touch occasionally with Ian. Someone else called KLE wrote a FORTH in Maclisp.

larsbrinkhoffon Brief History of PDP Computers

True enough, but I'll observe there's a lot of rounding out that could be done in various directions if one were so inclined.

larsbrinkhoffon Brief History of PDP Computers

The PDP-4 isn't binary compatible with the PDP-1. There is compatibility within the 4/7/9/15 line. So the PDP-1 stands out, and in that sense the lineage isn't direct.

larsbrinkhoffon Brief History of PDP Computers

I laughed (with suitable derision) when I saw the line from PDP-10 to VAX.

larsbrinkhoffon Brief History of PDP Computers

Also the dual-mode LINC-8 which was the immediate PDP-12 predecessor. It was as much a PDP in all but the name.

larsbrinkhoffon Xorshift Generators

It's both.

larsbrinkhoffon Xorshift Generators

LLMs adopted phrases from humans. But now humans adopt phrases from LLMs.

larsbrinkhoffon Xorshift Generators

Xorshift-36 for the PDP-10, with help from Sebastiano Vigna.

https://github.com/larsbrinkhoff/xoroshiro-36

larsbrinkhoffon Starring the Computer

This says PDP-7. https://www.reddit.com/r/westworld/comments/56tkt8/what_prog...

larsbrinkhoffon A brief tour of the PDP-11, the most influential minicomputer of all time (2022)

Then maybe also give a nod to the LINC, showing DEC a small 12-bit computer could be made.

larsbrinkhoffon A brief tour of the PDP-11, the most influential minicomputer of all time (2022)

BASIC was developed on GE mainframes.

larsbrinkhoffon Chaosnet (1981)

Chaosnet was inspired by the experimental 3 Mbits/s Ethernet in use at Xerox PARC at the time. Experimental Ethernet has a 8-bit node address; Chaosnet has 16 bits, of which 8 is network and another 8 is the node. The Chaosnet data rate is 4 Mbits/s.

On top of the hardware protocol, Chaosnet also defined the higher-level transport and session layer protocol. Applications are addressed by a name string rather than a port number; e.g. "TELNET" instead of 23. This protocol was retained when the NIC hardware was replaced with stock Ethernet.

larsbrinkhoffon Chaosnet (1981)

Chaosnet in active use, mostly on emulators: https://chaosnet.net/

Lispm, PDP-10, PDP-11, VAX.

larsbrinkhoffon Chaosnet (1981)

Yes, and in Ethernet frames as EtherType 0x0804.

larsbrinkhoffon Talking to strangers at the gym

"Her barbell is a special women's barbell."

FYI, it was probably just a regular women's weightlifting barbell. They are somewhat lighter, and have a thinner grip. Maybe she's serious about her weightlifting training.

https://en.wikipedia.org/wiki/Olympic_weightlifting#Barbell

larsbrinkhoffon Hand Drawn QR Codes (2025)

By the way, I also coded a QR symbol generator in PDP-10 assembly language.

https://github.com/PDP-10/its/blob/master/src/lars/qrcode.8

larsbrinkhoffon Hand Drawn QR Codes (2025)

I hand drew this on a whiteboard. It was a lot more work than I anticipated.

http://lars.nocrew.org/tmp/qr.png

larsbrinkhoffon 5x5 Pixel font for tiny screens

The LINC minicomputer operating system LAP6 came with a 4x5 font, but it didn't have lower case.

larsbrinkhoffon Ubuntu 26.04 Ends 46 Years of Silent sudo Passwords

It's built into the Unix terminal driver. Control-U is the default, but it can be changed with e.g. "stty kill". Libraries like readline also support it.

larsbrinkhoffon Ubuntu 26.04 Ends 46 Years of Silent sudo Passwords

Just type Control-U once.

larsbrinkhoffon SBCL: A Sanely-Bootstrappable Common Lisp (2008) [pdf]

https://twitter.com/Jonathan_Blow/status/2028903268265672728

larsbrinkhoffon SBCL: A Sanely-Bootstrappable Common Lisp (2008) [pdf]

Jonathan Blow: "It’s about a compiler written in Python FFS."

larsbrinkhoffon Steel Bank Common Lisp

https://www.sbcl.org/history.html

https://cmucl.org/doc/cmucl-history.html

https://en.wikipedia.org/wiki/Spice_Lisp

larsbrinkhoffon Steel Bank Common Lisp

SBCL has been in the works since 1980.

larsbrinkhoffon Show HN: R3forth, a ColorForth-inspired language with a tiny VM

Source: "The Invention of Forth", by Chuck Moore. https://colorforth.github.io/HOPL.html

larsbrinkhoffon Show HN: Micropolis/SimCity Clone in Emacs Lisp

Emacs is needed because it provides Emacs Lisp.

larsbrinkhoffon Show HN: R3forth, a ColorForth-inspired language with a tiny VM

Forth was invented before Moore worked at NRAO. Granted, it was gradually expanded from a very small interpreter, so it's hard to say exactly when it became "Forth" as we mean it today.

larsbrinkhoffon Show HN: Micropolis/SimCity Clone in Emacs Lisp

Sorry, I don't know anything about Emacs graphics. Some people confuse me with larsi, but I'm not that guy.

larsbrinkhoffon Show HN: Micropolis/SimCity Clone in Emacs Lisp

Lisp dialects have diverged quite a bit, and it would be a lot of work to bridge the differences to a degree approaching 100%. 90% is easy, but only works for small trivial programs.

I say this, having written a "95%" Common Lisp for Emacs (still a toy), and successfully ran an old Maclisp compiler and assembler in Common Lisp.

https://github.com/larsbrinkhoff/emacs-cl

https://github.com/PDP-6/ITS-138/blob/master/tools/maclisp.l...

larsbrinkhoffon Show HN: Micropolis/SimCity Clone in Emacs Lisp

Having read that, I'm even less convinced it's not more than a toy.