Robert van Engelen, PhD
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engelen.bsky.social
Robert van Engelen, PhD
@engelen.bsky.social
Possessed by math and coding since the 80s, vintage tech enthusiast, steam engines fanatic, CEO/CTO of Genivia, fmr Professor of Computer Science and Scientific Computing | NYC | 🇺🇸🇳🇱 | defend democracy | support 🇺🇦 | please be kind to animals🙏
Yesterday’s chore: fighting back Entropy by recombining kids Lego pieces back into complete sets to save. But Lego fought back with some brittle brown pieces self-destructing in my hand 💥 So sad 😔
November 12, 2025 at 12:47 PM
Toshiba HX-10 AA checkup and cleaning. Mechanical Alps keyboard is rock solid and very nice to type on. Having great fun with this industrial-looking beauty. Good to have and use for my ForthMSX development and testing with MegaRam and PicoMSX+. #MSX #Forth
November 9, 2025 at 5:28 PM
Fixed! RGB output via Scart Looks amazing (compared to composite). A tiny bit of jailbars effect on the blue background, something to fix later perhaps. Likely some other caps that are out of spec.
November 6, 2025 at 5:27 PM
Fixing a Sony Hit Bit 75B 1983. Let’s see if this baby works. I suspect it was not turned on for decades, as the 240V UK power cord was cut off. Got that fixed. But before I power this thing on, I want to replace the two crusty filter caps at the 462 and 473 transistor boards above a huge heat sink.
November 5, 2025 at 3:49 AM
Reposted by Robert van Engelen, PhD
November 2, 2025 at 5:17 PM
🎃 "Headless Slicer" cuts deep on Halloween nights 😱 Can you guess what it does? Some new retro wizardry Forthcoming! #retro #halloween #msx #forth #compiler #z80
October 31, 2025 at 7:46 PM
Happy retro Halloween! 🎃
October 31, 2025 at 11:36 AM
Reposted by Robert van Engelen, PhD
But does it connect to an Atari or Commodore 8-bit computer? Or maybe a 2-bit computer?
Pantogram’s miniature binary typewriter
spoon-tamago.com/pantograph-i...
October 28, 2025 at 2:26 PM
Reposted by Robert van Engelen, PhD
I keep trying to tell people about #FujiNet.
That it is a WiFi adapter for your favorite #Atari8bit, #Apple2, #ColecoAdam, #TRS80CoCo, #Commodore, #Atari2600, #AtariLynx, and #MSDOS machines, with more to come.

But word isn't getting out.

Can u help?

fujinet.online
FujiNet - The Future of Retro Computing
The Future of Retro Computing
fujinet.online
October 18, 2025 at 7:17 PM
Made some progress! Got MSX VDP and VRAM access and control in ForthMSX now working. Playing around with a bit of Forth code to twinkle bitmapped stars live on screen in text mode (picture only below, sorry no GIF). Much faster than BASIC on my Sony MSX2. #MSX #Forth #Z80 github.com/Robert-van-E...
October 18, 2025 at 8:19 PM
🎉 ForthMSX is now available as open source on GitHub GitHub.com/Robert-van-E...
Having fun coding a new Forth interpreter/compiler in Z80 assembly for the MSX. Making it wicked fast, based on Forth850 that I wrote for the Sharp PC850. MSX Pico+ is a *fantastic* cartridge to get my files over wifi. No AI coding assistance needed, thank you. #MSX #forth
October 16, 2025 at 8:36 PM
More fun stuff this weekend with my new Forth system for the MSX. New Forth words for floats using the MSX built-in Math Pack and new Forth file system words using MSX-DOS1. Forth internals are mostly written in assembly for speed. Next up are graphics+sound for game dev. #MSX #Forth #z80 #assembly
October 12, 2025 at 5:23 PM
Reposted by Robert van Engelen, PhD
#Sharptember A chance find amongst a bunch of tapes I won in an auction turned up something pretty interesting, a compilation tape of games written by Col Needham (the inventor of IMDb) and possibly his master tape from which he sold his mail order games. Here's his game "UFO Attack".
September 28, 2025 at 7:17 PM
Having fun coding a new Forth interpreter/compiler in Z80 assembly for the MSX. Making it wicked fast, based on Forth850 that I wrote for the Sharp PC850. MSX Pico+ is a *fantastic* cartridge to get my files over wifi. No AI coding assistance needed, thank you. #MSX #forth
September 22, 2025 at 6:58 PM
Reposted by Robert van Engelen, PhD
#RIP Robert Redford.

➡️BREAKING: Robert #Redford, the actor and director who sailed to Hollywood stardom with turns in classics such as “Butch Cassidy and the Sundance Kid” and “All the President’s Men” died Tuesday morning at his home in Utah.

He was 89.
September 16, 2025 at 12:28 PM
I’ve updated tinylisp in 99 lines of C. Adding color output to Lisp traces in the “extras” version. Also added backquoting/unquoting and some more examples. #lisp github.com/Robert-van-E...
GitHub - Robert-van-Engelen/tinylisp: Lisp in 99 lines of C and how to write one yourself. Includes 21 Lisp primitives, garbage collection and REPL. Includes tail-call optimized versions for speed and...
Lisp in 99 lines of C and how to write one yourself. Includes 21 Lisp primitives, garbage collection and REPL. Includes tail-call optimized versions for speed and reduced memory use. - Robert-van-E...
github.com
August 8, 2025 at 11:38 PM
Didn’t think it was possible, but Super Mario World runs on MSX2 (Sony HB-F1XD) with MSX Pico+ cartridge. Sound and music with SCC on the audio jack. Brilliant! #MSX
August 8, 2025 at 8:38 PM
Reposted by Robert van Engelen, PhD
Blue Ghost's view of the moon at 100km altitude.

-Credits: NASA
July 29, 2025 at 7:48 AM
Reposted by Robert van Engelen, PhD
Open Circuits is a photographic exploration of the beautiful design inside everyday electronics. Its stunning cross-section photography unlocks a hidden world full of elegance, subtle complexity, and wonder. amzn.to/3H6M1H8 #electronics #photography
Open Circuits: The Inner Beauty of Electronic Components (Packaging may vary)
Open Circuits: The Inner Beauty of Electronic Components (Packaging may vary) [Oskay, Windell, Schlaepfer, Eric] on Amazon.com. *FREE* shipping on qualifying offers. Open Circuits: The Inner Beauty of Electronic Components (Packaging may vary)
amzn.to
July 24, 2025 at 6:48 PM
Tinylisp in 99 lines of C added an "extras" version with more user-friendly features and runtime optimizations explained in the accompanying article. #lisp github.com/Robert-van-E...
GitHub - Robert-van-Engelen/tinylisp: Lisp in 99 lines of C and how to write one yourself. Includes 21 Lisp primitives, garbage collection and REPL. Includes tail-call optimized versions for speed and...
Lisp in 99 lines of C and how to write one yourself. Includes 21 Lisp primitives, garbage collection and REPL. Includes tail-call optimized versions for speed and reduced memory use. - Robert-van-E...
github.com
July 23, 2025 at 12:43 PM
Got some lovely new MSX goodies ❤️
July 22, 2025 at 7:37 PM
Reposted by Robert van Engelen, PhD
Here's Your Third (And Probably Final) Chance To Own A ZX Spectrum Next. (Image: @ZXSpectrumNext) (Repost)
Here's Your Third (And Probably Final) Chance To Own A ZX Spectrum Next
"Mark the date, spread the word far and wide"
www.timeextension.com
June 25, 2025 at 4:50 PM
Reposted by Robert van Engelen, PhD
Colored droplets in corn syrup seemingly blended together can be returned to their original state by reversing the direction of mixing, a form of laminar flow called "Stokes flow".

Credit: UNM Physics & Astronomy
July 14, 2025 at 11:54 PM
Reposted by Robert van Engelen, PhD
“Superman is too woke!”

Literally the first page of the first ever appearance of Superman:
July 11, 2025 at 1:58 PM