Lab Notes

Experiments with computing, electronics, and maker crafts.

Using MEGA65's Matrix Mode

July 31, 2022

The MEGA65 has a powerful debugging facility built into it that would have been high fantasy for vintage computer programmers back in the day: the Matrix Mode debugger. Today in Lab Notes, we explore Matrix Mode’s capabilities to further help us with assembly language programming, continuing to use our Game of Life program as an example.

Using the MEGA65 Monitor to troubleshoot assembly programs

July 26, 2022

When we last attempted an assembly language program for the MEGA65, I described debugging techniques that involve inventing ways to visualize the memory and behavior of your program, often requiring adding code to the program temporarily to do so. Today I want to explore a feature of the MEGA65 that can help with this, the MEGA65 machine language monitor, using our Game of Life program as an example.

Game of Life on the MEGA65, in assembly language

July 23, 2022

Previously, we explored Conway’s Game of Life for the MEGA65 in BASIC. Let’s try it again, this time in assembly language, using the same BASIC timing code for comparison.

Game of Life on the MEGA65, in BASIC

July 20, 2022

Conway’s Game of Life is a classic math game that’s also a fun beginner’s programming project. With a grid of cells and a few simple rules, a flourishing biome of digital organisms comes to life. Let’s try building it for the MEGA65 using BASIC!

Adding a feature to the MEGA65

June 17, 2022

On every Commodore computer that has a Home key, I routinely hit Home when I mean to hit the Del key. The only way to move the cursor back to where I need it is with the arrow keys. With the MEGA65, I finally have the opportunity to do something about this, once and for all.

Welcome to the MEGA65

June 12, 2022

The MEGA65 is a new personal computer based on the Commodore 65, the unreleased 1991 sequel to the inimitable Commodore 64 and 128 home computers of the 1980’s. I’m so excited about mine, I wrote the MEGA65 Welcome Guide, a supplementary booklet for new owners.

Electronic Bulletin Boards by Carolyn E. Cooper, a book report

January 10, 2022

Electronic Bulletin Boards by Carolyn E. Cooper, a book report by Dan Sanderson, age 12. Six handwritten pages, in cursive, with a cover page and five printed pages of figures from a Boise BBS. I got an A+.

What if the Bee had an S?

December 12, 2021

What would it be like if the #nytspellingbee had an S in it?

@thegridkid is on record as saying an S-Bee would be “too easy,” a nice way of saying it’s difficult to balance difficulty, size, and funness. I wanted a sense of this design space, so I did some computer’ing.

PICO-8 on the RG 351M handheld game console

November 18, 2021

Wow, #pico8 on the RG 351M handheld game console is fantastic! This one from Anbernic is metal, heavy, with solid controls. $139 USD is pricey but worth it.

Angle math demo in PICO-8

November 1, 2021

We were discussing angles and coordinates in the #pico8 Discord and I whipped up this quick demo while we were chatting. It’s a neat demo, and super-neat how easy it was to put it together! The value of a tight feedback loop cannot be understated.…