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
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.
Mac Plus. I still have it (and it functions—needed recapping and reflowing the solder on the main connector on the mobo).
November 2, 2025 at 1:28 PM
Mac Plus. I still have it (and it functions—needed recapping and reflowing the solder on the main connector on the mobo).
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.
So got some prototype PCBs from JLCPCB. In playing with one I tried a direct short from base to emitter with no current limiting.
Away with thee, magic smoke!
Bodging some protective resistors to see if they protect the smoke but don't interfere with the circuits. (Adding another pair now.)
Away with thee, magic smoke!
Bodging some protective resistors to see if they protect the smoke but don't interfere with the circuits. (Adding another pair now.)
October 11, 2025 at 12:01 AM
So got some prototype PCBs from JLCPCB. In playing with one I tried a direct short from base to emitter with no current limiting.
Away with thee, magic smoke!
Bodging some protective resistors to see if they protect the smoke but don't interfere with the circuits. (Adding another pair now.)
Away with thee, magic smoke!
Bodging some protective resistors to see if they protect the smoke but don't interfere with the circuits. (Adding another pair now.)
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.)
Getting a "Buc-ee's" vibe from Wallys.
I started a project to create modern road trip place-mats. Here is I-80 across Iowa:
I started a project to create modern road trip place-mats. Here is I-80 across Iowa:
September 29, 2025 at 2:37 PM
Getting a "Buc-ee's" vibe from Wallys.
I started a project to create modern road trip place-mats. Here is I-80 across Iowa:
I started a project to create modern road trip place-mats. Here is I-80 across Iowa:
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.)
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
Custom water-slide decals arrived. They help take this balsa model to the next level.
Studio-scale model (about 44" long) was designed in Affinity Designer, laser cut, coverered with Monokote. Then painted & a few 3D modeled parts added. Now decals.
From "2001: A Space Odyssey."
#scifimodelling
Studio-scale model (about 44" long) was designed in Affinity Designer, laser cut, coverered with Monokote. Then painted & a few 3D modeled parts added. Now decals.
From "2001: A Space Odyssey."
#scifimodelling
March 15, 2025 at 8:47 PM
Custom water-slide decals arrived. They help take this balsa model to the next level.
Studio-scale model (about 44" long) was designed in Affinity Designer, laser cut, coverered with Monokote. Then painted & a few 3D modeled parts added. Now decals.
From "2001: A Space Odyssey."
#scifimodelling
Studio-scale model (about 44" long) was designed in Affinity Designer, laser cut, coverered with Monokote. Then painted & a few 3D modeled parts added. Now decals.
From "2001: A Space Odyssey."
#scifimodelling
March 5, 2025 at 5:58 PM
My #minirack & #homelab is just getting started. Two Pis share space with a switch.
A Pi 4 is running OpenWebRX+ & has two SDR boxes attached. I can scan the radio spectrum from any browser.
Other Pi (5 with 16GB) is running Open WebUI & a number of local LLMs.
Hoping to add a #GlobalTalk device.
A Pi 4 is running OpenWebRX+ & has two SDR boxes attached. I can scan the radio spectrum from any browser.
Other Pi (5 with 16GB) is running Open WebUI & a number of local LLMs.
Hoping to add a #GlobalTalk device.
March 5, 2025 at 3:37 AM
My #minirack & #homelab is just getting started. Two Pis share space with a switch.
A Pi 4 is running OpenWebRX+ & has two SDR boxes attached. I can scan the radio spectrum from any browser.
Other Pi (5 with 16GB) is running Open WebUI & a number of local LLMs.
Hoping to add a #GlobalTalk device.
A Pi 4 is running OpenWebRX+ & has two SDR boxes attached. I can scan the radio spectrum from any browser.
Other Pi (5 with 16GB) is running Open WebUI & a number of local LLMs.
Hoping to add a #GlobalTalk device.
In knew in 2021 that it was my last year working at Apple. So I suddenly started looking at where I worked as though I was a tourist.
Here are some Apple Park photos. Perhaps you'll understand why I have described it as something like a beautiful art gallery — with no art.
#MARCHintosh
Here are some Apple Park photos. Perhaps you'll understand why I have described it as something like a beautiful art gallery — with no art.
#MARCHintosh
March 4, 2025 at 3:23 PM
In knew in 2021 that it was my last year working at Apple. So I suddenly started looking at where I worked as though I was a tourist.
Here are some Apple Park photos. Perhaps you'll understand why I have described it as something like a beautiful art gallery — with no art.
#MARCHintosh
Here are some Apple Park photos. Perhaps you'll understand why I have described it as something like a beautiful art gallery — with no art.
#MARCHintosh