Hardware & Software Hobby Projects

I Built an Altair 8800 Emulator

Altair 8800 was the first popular home computer (1975), priced for the home market: $500US base price with 256 bytes of memory, toggle switches for input and LEDs for output, Intel 8080 CPU, the same CPU used in the first IBM personal computer.

image My Altair 8800 emulator has a similar front panel to the original.
It's capable of running the same as the original Altair in this video.

I upgraded mine with an MP3 player, digital clock, and SD card for program storage.
An Arduino Due or Mega 2560 is used as the motherboard: CPU and RAM.
I bought the hardware components such as toggles, LEDs, and resisters from Chinese companies on eBay. The Arduino Mega 2560 or Due boards on Amazon.
The computer box and front panel are from Adwater and Stir.

I wrote an Instructable article: Altair 8800 Arduino Emulator With a Virtual Front Panel. The steps show how to setup and run an Altair 8800 emulator that runs on an Arduino Mega 2560 or an Arduino Due. I/O is through the Arduino serial port to your computer.
+ Machine code processor which I wrote. I used David Hansel's Intel 8080 opcode program code.
+ Assembler program that I wrote. Click here for a simple sample loop program.

The Altair 8800 was on the cover of Popular Electronics magazine which I read in the high school library. I wanted one, but at the time I could not afford the upgrades such as permanent storage, a floppy drive. In 1983 I bought my first commercial grade computer, a Columbia portable computer that launch my computer career. It cost $3,200, over $10,000 in today's dollars(year: 2025). That's less than most people spend on a modern computer, mobile phone, and flat screen TV.

image Columbia VP portable, 1983: 8088 chip(upgrade from the 8080), 384K of RAM(upgraded), 2 floppy disk units, small tube TV screen, and keyboard.

Home Office Project

I work for Twilio, a communications internet cloud service company.

image Home office phone system:
I use the Twilio SIP Domain product to manage my home phone number which is a Twilio phone number. I have a landline and an analog wireless home phone. I like that I don't have to carry around my mobile phone when I at home.
And, I can give out this phone number instead of my mobile phone number. As well, I have multiple phone numbers for this one device: home office number and home personal number.
I did have to setup my own voicemail(Studio version).

Pong Game

Pong was the first popular home computer game console(1972).

image Game code with setup instructions. I started with Arduino Pong By Pete Lamonica and made updates.
image
   Found an improved pong game.