code · Getting Started
10 PRINT for the KIM-1
Implementing 10PRINT on a KIM-1 clone (PAL-II) in both Microsoft BASIC and 6502 assembly, displaying the maze on the 7-segment LED display.
May 16, 2025 · 7 min
C64 · code
Building a software serial bridge
Modern and retro mix One of my favorite peices of retro clone hardware is Bob Corsham’s KIM-1 Clone. I’ve featured it many places like the …
May 5, 2023 · 5 min
C64 · code
Blinkenlights
Driving LEDs from the VIC-20 and KIM-1 USR ports. Binary counting in the real world with vintage hardware.
Mar 2, 2023 · 7 min
C64 · code
40 years on, this is still the best maze algorithm
Exploring the elegant maze generator from Compute! magazine (December 1981). A line-by-line breakdown of how this classic BASIC algorithm works.
Jan 26, 2023 · 5 min
C64 · code
Validating Pilish
Writing code to validate Pilish text—prose where word lengths match the digits of Pi. Implementations in Julia and Commodore BASIC.
Dec 1, 2022 · 5 min
C64 · code
My mostly retro writing platform contenders in National Novel Writing Month for 2022 NaNoWriMo
Evaluating vintage computers for NaNoWriMo 2022: VIC-20, Plus/4, Commodore 64, and PET. Word processing on 8-bit machines with SpeedScript and other …
Oct 21, 2022 · 6 min
code · Commodore
MOS paper tape format
Understanding the MOS paper tape format used by the KIM-1 and other 6502 systems. Breaking down the hex format line by line with checksum …
Jul 7, 2022 · 2 min
C64 · code
A little more speed from the 6502
Optimizing 6502 memory transfers beyond the general-purpose approach. Testing on a 1MHz KIM-1 clone with precise timing measurements.
Jun 22, 2022 · 4 min
C64 · code
How fast can a 6502 transfer memory
Testing real-world memory transfer speeds on 6502 machines. Inspired by Apple M2 marketing, let’s see what Commodore hardware can actually do.
Jun 14, 2022 · 8 min
code · Commodore
Almost primes with TinyBASIC on the KIM-1 clone: PAL-1
Finding k-almost-primes using TinyBASIC on a KIM-1 clone. A look at the copyleft origins of TinyBASIC and Bill Gates’ infamous open letter.
May 25, 2022 · 3 min
C64 · code
64 Bit Addition and Products on Commodore: The Wheat and Chessboard problem
Implementing 64-bit arithmetic in 6502 assembly to solve the wheat and chessboard problem. Handling numbers too large for standard calculators on …
May 10, 2022 · 5 min
code · Commodore
Fibonacci 1-10 on the KIM-1 (and clones)
Computing and displaying the first 10 Fibonacci numbers on a KIM-1’s hex display. Learning 6502 assembly the hard way with pencil and paper.
Mar 24, 2022 · 5 min