John Calhoun
@engineersneedart.com
Old Macintosh shareware author. Making things I wish existed when I was a kid.
engineersneedart.com
github.com/EngineersNeedArt
engineersneedart.com
github.com/EngineersNeedArt
Playing with analog computing (but digital metering, so sue me).
Last night (after several hours of hair pulling) I learned that a 1% 10 kΩ resistor color bands is indistinguishable from a 1% 120Ω resistor—that is flipped around.
Breadboarding is messy. Will make up a PCB for part of it soon.
Last night (after several hours of hair pulling) I learned that a 1% 10 kΩ resistor color bands is indistinguishable from a 1% 120Ω resistor—that is flipped around.
Breadboarding is messy. Will make up a PCB for part of it soon.
November 26, 2025 at 2:35 PM
Playing with analog computing (but digital metering, so sue me).
Last night (after several hours of hair pulling) I learned that a 1% 10 kΩ resistor color bands is indistinguishable from a 1% 120Ω resistor—that is flipped around.
Breadboarding is messy. Will make up a PCB for part of it soon.
Last night (after several hours of hair pulling) I learned that a 1% 10 kΩ resistor color bands is indistinguishable from a 1% 120Ω resistor—that is flipped around.
Breadboarding is messy. Will make up a PCB for part of it soon.
Scored my copy today. Limited run, FWIW.
Chronic Town together with Murmur, the band’s earliest IRS releases, are now available via the Definitive Sound Series–a meticulous One-Step vinyl process renowned for its superior sound quality. Pre-order here: interscope.com/products/chr...
November 19, 2025 at 6:32 PM
Scored my copy today. Limited run, FWIW.
I put together an electronics kit + book intended as a gentle introduction to transistors and early computer logic gates (resistor-transistor logic or RTL).
I set up a Tindie store page for the little over a dozen I have readied. (I'll create a web site soon.)
www.tindie.com/products/jca...
I set up a Tindie store page for the little over a dozen I have readied. (I'll create a web site soon.)
www.tindie.com/products/jca...
Transistor Logic Pixie by EngineersNeedArt on Tindie
An educational kit to learn about transistors and simple logic gates. Easy for beginners and a stepping stone to more advanced electronics.
www.tindie.com
November 17, 2025 at 7:55 PM
I put together an electronics kit + book intended as a gentle introduction to transistors and early computer logic gates (resistor-transistor logic or RTL).
I set up a Tindie store page for the little over a dozen I have readied. (I'll create a web site soon.)
www.tindie.com/products/jca...
I set up a Tindie store page for the little over a dozen I have readied. (I'll create a web site soon.)
www.tindie.com/products/jca...
A second analog (integrator) channel breadboarded (top). Both channels are tapped and displayed on the ESP32 "software meter" in the center (showing two needles at once).
The new channel uses dual op-amps instead of singles. I may make another analog channel and have a go with a quad op-amp.
The new channel uses dual op-amps instead of singles. I may make another analog channel and have a go with a quad op-amp.
November 11, 2025 at 11:10 PM
A second analog (integrator) channel breadboarded (top). Both channels are tapped and displayed on the ESP32 "software meter" in the center (showing two needles at once).
The new channel uses dual op-amps instead of singles. I may make another analog channel and have a go with a quad op-amp.
The new channel uses dual op-amps instead of singles. I may make another analog channel and have a go with a quad op-amp.
From breadboard (left—wires can be bumped loose) to protoboard (right—wires soldered).
One channel of an analog/digital hybrid computer experiment.
An op-amp acts as an analog-computer integrator, 3 more op-amps scale, offset & invert the voltage so it is within 0.0-3.3V range for the ESP32 ADCs.
One channel of an analog/digital hybrid computer experiment.
An op-amp acts as an analog-computer integrator, 3 more op-amps scale, offset & invert the voltage so it is within 0.0-3.3V range for the ESP32 ADCs.
November 10, 2025 at 11:16 PM
From breadboard (left—wires can be bumped loose) to protoboard (right—wires soldered).
One channel of an analog/digital hybrid computer experiment.
An op-amp acts as an analog-computer integrator, 3 more op-amps scale, offset & invert the voltage so it is within 0.0-3.3V range for the ESP32 ADCs.
One channel of an analog/digital hybrid computer experiment.
An op-amp acts as an analog-computer integrator, 3 more op-amps scale, offset & invert the voltage so it is within 0.0-3.3V range for the ESP32 ADCs.
Each year the wife hand-carves a multi-color X-mas card. A destructive process: inking/printing a color before carving for the next color.
This year I suggested she make just one print at each stage (in black ink) for me to scan digitally—print on the Risograph.
Seems to be going well.
This year I suggested she make just one print at each stage (in black ink) for me to scan digitally—print on the Risograph.
Seems to be going well.
November 10, 2025 at 3:38 PM
Each year the wife hand-carves a multi-color X-mas card. A destructive process: inking/printing a color before carving for the next color.
This year I suggested she make just one print at each stage (in black ink) for me to scan digitally—print on the Risograph.
Seems to be going well.
This year I suggested she make just one print at each stage (in black ink) for me to scan digitally—print on the Risograph.
Seems to be going well.
Dialing back to the 1990's and the first commercial Glider (4.0) game…
Ward Hartenstein blew my mind when I downloaded his "Hands-Off House" from AOL. You don't touch the controls to play—the house itself takes care of moving the glider along.
B&W version playthrough:
youtu.be/nIzy_Fmjexs
Ward Hartenstein blew my mind when I downloaded his "Hands-Off House" from AOL. You don't touch the controls to play—the house itself takes care of moving the glider along.
B&W version playthrough:
youtu.be/nIzy_Fmjexs
Glider 4.0 || Hands-Off House
YouTube video by James Howell
youtu.be
November 9, 2025 at 2:22 AM
Dialing back to the 1990's and the first commercial Glider (4.0) game…
Ward Hartenstein blew my mind when I downloaded his "Hands-Off House" from AOL. You don't touch the controls to play—the house itself takes care of moving the glider along.
B&W version playthrough:
youtu.be/nIzy_Fmjexs
Ward Hartenstein blew my mind when I downloaded his "Hands-Off House" from AOL. You don't touch the controls to play—the house itself takes care of moving the glider along.
B&W version playthrough:
youtu.be/nIzy_Fmjexs
Just having some fun at Pioneer's expense, I guess.
#SpacetoberChallenge #sciart #spaceart #illustration
#SpacetoberChallenge #sciart #spaceart #illustration
October 26, 2025 at 3:14 AM
Just having some fun at Pioneer's expense, I guess.
#SpacetoberChallenge #sciart #spaceart #illustration
#SpacetoberChallenge #sciart #spaceart #illustration
Sweep meter is better. (Here it is responding to potentiometer acting as a voltage divider.)
October 23, 2025 at 5:23 PM
Sweep meter is better. (Here it is responding to potentiometer acting as a voltage divider.)
Working on an "analog" voltage meter for a project. (This slide-rule version will not make the cut.)
October 23, 2025 at 2:07 PM
Working on an "analog" voltage meter for a project. (This slide-rule version will not make the cut.)
After all this iteration, I placed an order for (I hope) the final board. Finishing up the instruction manual as well. I should have the boards for sale on Tindie in November. They're a kind of "breadboard helper" for playing with (learning about) transistor logic circuits.
October 18, 2025 at 3:04 PM
After all this iteration, I placed an order for (I hope) the final board. Finishing up the instruction manual as well. I should have the boards for sale on Tindie in November. They're a kind of "breadboard helper" for playing with (learning about) transistor logic circuits.
Reposted by John Calhoun
I've just posted a video that *tries* to document the overwhelming nature of the event (overwhelming in a good way, of course).
And I think I only covered like 1/3 of the show floor!
Video: www.youtube.com/watch?v=hF0N...
Blog post: www.jeffgeerling.com/blog/2025/vc...
And I think I only covered like 1/3 of the show floor!
Video: www.youtube.com/watch?v=hF0N...
Blog post: www.jeffgeerling.com/blog/2025/vc...
Resurrecting old tech at VCF Midwest
YouTube video by Jeff Geerling
www.youtube.com
October 16, 2025 at 2:05 PM
I've just posted a video that *tries* to document the overwhelming nature of the event (overwhelming in a good way, of course).
And I think I only covered like 1/3 of the show floor!
Video: www.youtube.com/watch?v=hF0N...
Blog post: www.jeffgeerling.com/blog/2025/vc...
And I think I only covered like 1/3 of the show floor!
Video: www.youtube.com/watch?v=hF0N...
Blog post: www.jeffgeerling.com/blog/2025/vc...
History of Glider for Macintosh
YouTube video by Classic Mac Gaming
youtu.be
October 11, 2025 at 5:23 PM
Prototyping my first learning-electronics project kit is winding down (I am finishing up the manual as well). Top is through-hole, bottom my first go at surface-mount (I learned a few things and have changed it some).
(Hard to find a domain name these days. Went with CircuitPixies.)
(Hard to find a domain name these days. Went with CircuitPixies.)
October 2, 2025 at 2:07 PM
Prototyping my first learning-electronics project kit is winding down (I am finishing up the manual as well). Top is through-hole, bottom my first go at surface-mount (I learned a few things and have changed it some).
(Hard to find a domain name these days. Went with CircuitPixies.)
(Hard to find a domain name these days. Went with CircuitPixies.)
September 20, 2025 at 12:35 AM
My oldest daughter and I each have refurb'ed Riso machines. But she has a blue ink drum and I do not. With her visiting for a few days, she brought her drums and I was able to test a few Riso ideas out.
#riso
#risograph
#riso
#risograph
September 17, 2025 at 5:35 PM
My oldest daughter and I each have refurb'ed Riso machines. But she has a blue ink drum and I do not. With her visiting for a few days, she brought her drums and I was able to test a few Riso ideas out.
#riso
#risograph
#riso
#risograph
Thanks, @ronscompvids.bsky.social for your midwest hospitality at #vcfmw this year. (And so many Mac laptops!) See you next year.
September 15, 2025 at 2:54 AM
Thanks, @ronscompvids.bsky.social for your midwest hospitality at #vcfmw this year. (And so many Mac laptops!) See you next year.
The process of prototyping an electronic project/PCB (from top to bottom). (I'm finishing up the project book now.)
September 7, 2025 at 9:45 PM
The process of prototyping an electronic project/PCB (from top to bottom). (I'm finishing up the project book now.)
Some somber thoughts on genealogy and the introduction of the camera.
engineersneedart.com/blog/camera/...
engineersneedart.com/blog/camera/...
Camera Genealogica (Part 1)
engineersneedart.com
July 31, 2025 at 1:14 PM
Some somber thoughts on genealogy and the introduction of the camera.
engineersneedart.com/blog/camera/...
engineersneedart.com/blog/camera/...
Writing about your most embarrassing fuckups was, I thought, supposed to be more cathartic. Like the line from "Pink Rabbits", it wasn't that at all. 🫤
engineersneedart.com/blog/almostf...
engineersneedart.com/blog/almostf...
Almost Fired
engineersneedart.com
July 4, 2025 at 3:30 AM
Writing about your most embarrassing fuckups was, I thought, supposed to be more cathartic. Like the line from "Pink Rabbits", it wasn't that at all. 🫤
engineersneedart.com/blog/almostf...
engineersneedart.com/blog/almostf...
So a guy (Daniel Valcanover) has spent 25 years trying to find a boxed version of the original Glider for Windows has tracked one down.
Apparently he'll post the binary on MobyGames soon. Maybe here: www.mobygames.com/game/3998/gl...
Even a photo of the box was unobtainium — until now of course.
Apparently he'll post the binary on MobyGames soon. Maybe here: www.mobygames.com/game/3998/gl...
Even a photo of the box was unobtainium — until now of course.
June 4, 2025 at 6:14 PM
So a guy (Daniel Valcanover) has spent 25 years trying to find a boxed version of the original Glider for Windows has tracked one down.
Apparently he'll post the binary on MobyGames soon. Maybe here: www.mobygames.com/game/3998/gl...
Even a photo of the box was unobtainium — until now of course.
Apparently he'll post the binary on MobyGames soon. Maybe here: www.mobygames.com/game/3998/gl...
Even a photo of the box was unobtainium — until now of course.
I'm not sure I ever received the floppy disk, but I have the box and manual for the (rare?) Japanese version of Glider 4.0.
Maybe someone can track down the binary.
#VintageMac #RetroGaming
Maybe someone can track down the binary.
#VintageMac #RetroGaming
May 18, 2025 at 3:00 AM
I'm not sure I ever received the floppy disk, but I have the box and manual for the (rare?) Japanese version of Glider 4.0.
Maybe someone can track down the binary.
#VintageMac #RetroGaming
Maybe someone can track down the binary.
#VintageMac #RetroGaming
Placemat you might have found in a diner in 1960.
I picked up a 1960 book of these placemats and I'm scanning all 200+ of them to upload to archive.org. It's one of those things I do from time to time.
I'll post when available.
Interstate 80 has mostly replaced US Highway 6 (below):
I picked up a 1960 book of these placemats and I'm scanning all 200+ of them to upload to archive.org. It's one of those things I do from time to time.
I'll post when available.
Interstate 80 has mostly replaced US Highway 6 (below):
May 14, 2025 at 4:32 PM
Placemat you might have found in a diner in 1960.
I picked up a 1960 book of these placemats and I'm scanning all 200+ of them to upload to archive.org. It's one of those things I do from time to time.
I'll post when available.
Interstate 80 has mostly replaced US Highway 6 (below):
I picked up a 1960 book of these placemats and I'm scanning all 200+ of them to upload to archive.org. It's one of those things I do from time to time.
I'll post when available.
Interstate 80 has mostly replaced US Highway 6 (below):
Finally (took 3 days of failed attempts) got Rocky Linux 9 installed with NVIDIA driver + CUDA toolkit so I can run Ollama on my an inexpensive 24GB NVIDIA TESLA M40 (seen on right — had to 3D print a shroud + add fans to the card).
Just tried phi4. Tokens are smokin'.
#localllama
Just tried phi4. Tokens are smokin'.
#localllama
April 9, 2025 at 11:14 PM
Finally (took 3 days of failed attempts) got Rocky Linux 9 installed with NVIDIA driver + CUDA toolkit so I can run Ollama on my an inexpensive 24GB NVIDIA TESLA M40 (seen on right — had to 3D print a shroud + add fans to the card).
Just tried phi4. Tokens are smokin'.
#localllama
Just tried phi4. Tokens are smokin'.
#localllama
Reposted by John Calhoun
One last video for #Marchintosh ! I take a look at @engineersneedart.com unfinished Mac games. www.youtube.com/watch?v=MlHs...
John Calhoun's Lost Mac Software!
YouTube video by Cameron Talley
www.youtube.com
March 29, 2025 at 9:10 PM
One last video for #Marchintosh ! I take a look at @engineersneedart.com unfinished Mac games. www.youtube.com/watch?v=MlHs...