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
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 😔
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
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.
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
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.
Addicted? Nah. Just always close to grab, like these on our counter right now.
November 1, 2025 at 11:48 AM
Addicted? Nah. Just always close to grab, like these on our counter right now.
Happy retro Halloween! 🎃
October 31, 2025 at 11:36 AM
Happy retro Halloween! 🎃
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
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...
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
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
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
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
Got some lovely new MSX goodies ❤️
July 22, 2025 at 7:37 PM
Got some lovely new MSX goodies ❤️
Enjoyed visiting the museum of steam engines in historic Medemblik, the Netherlands. Great people and fantastic historical engines on display.
June 22, 2025 at 2:37 PM
Enjoyed visiting the museum of steam engines in historic Medemblik, the Netherlands. Great people and fantastic historical engines on display.
Recently visited the Wouda-Gemaal, Netherlands. The largest Steam pumping station in the world. Four compound steam engines drive eight pumps. Still used when water levels inland are rising too quick for modern pumps to keep up. Burns biodiesel these days, so no longer belches soot into the air.
June 17, 2025 at 12:17 PM
Recently visited the Wouda-Gemaal, Netherlands. The largest Steam pumping station in the world. Four compound steam engines drive eight pumps. Still used when water levels inland are rising too quick for modern pumps to keep up. Burns biodiesel these days, so no longer belches soot into the air.
Daffodil Hill at the Bronx Botanical garden NY did not disappoint this year
April 28, 2025 at 10:49 AM
Daffodil Hill at the Bronx Botanical garden NY did not disappoint this year
Happy Easter! 🐰🐣🌷
April 20, 2025 at 4:28 PM
Happy Easter! 🐰🐣🌷
Weekend project to relax: the Sharp MZ-731 printer plotter works again after 40 years, fixed with new custom brass gears. Next up, fix the tape unit.
March 29, 2025 at 12:11 PM
Weekend project to relax: the Sharp MZ-731 printer plotter works again after 40 years, fixed with new custom brass gears. Next up, fix the tape unit.
The Casio AS-L is the first Casio calculator to use Japanese-made LSI in 1971. Mine works, except for the minus sign neon bulb does not light. I partly reverse-engineered the driver schematic. I believe the C284 transistor could be faulty. Not sure what would be a modern replacement npn transistor.
March 20, 2025 at 7:17 PM
The Casio AS-L is the first Casio calculator to use Japanese-made LSI in 1971. Mine works, except for the minus sign neon bulb does not light. I partly reverse-engineered the driver schematic. I believe the C284 transistor could be faulty. Not sure what would be a modern replacement npn transistor.
Exciting to hear Coco 2 is trending! They are talking about the TRS-80 Color Computer 2, right? Are they? #vintage #computing #retro #coco
March 20, 2025 at 6:43 PM
Exciting to hear Coco 2 is trending! They are talking about the TRS-80 Color Computer 2, right? Are they? #vintage #computing #retro #coco
Azaleas are profusely blooming this Spring. Humming with bumble bees.
March 19, 2025 at 6:25 PM
Azaleas are profusely blooming this Spring. Humming with bumble bees.
Another vintage calculator saved and fully restored. I’ve fixed 5 corroded copper traces and rebuilt the battery pack. 1970 Sanyo ICC-82D. It’s a cool one to use, even after 55 years.
March 13, 2025 at 7:27 PM
Another vintage calculator saved and fully restored. I’ve fixed 5 corroded copper traces and rebuilt the battery pack. 1970 Sanyo ICC-82D. It’s a cool one to use, even after 55 years.
Having fun with my pdp11/70 (PiDP-11 kit) running 2.11BSD UNIX, connecting over RS232 with a Tandy 102 using its builtin VT52 TELCOM program. Getting this setup to work properly wasn’t a cakewalk, but hey, so it wasn’t easy using computers back in the 70s and 80s! #pdp #pidp #retro #computing
February 25, 2025 at 9:53 PM
Having fun with my pdp11/70 (PiDP-11 kit) running 2.11BSD UNIX, connecting over RS232 with a Tandy 102 using its builtin VT52 TELCOM program. Getting this setup to work properly wasn’t a cakewalk, but hey, so it wasn’t easy using computers back in the 70s and 80s! #pdp #pidp #retro #computing
Good morning. Ready for work on my PiDP-11 with the original 80s manuals I used back then. #pdp #pidp #computing #retro
February 12, 2025 at 1:15 PM
Good morning. Ready for work on my PiDP-11 with the original 80s manuals I used back then. #pdp #pidp #computing #retro