Below you will find pages that utilize the taxonomy term “6502”
January 11, 2024
Machine Language: Count Faster on 6502
I’ve done a lot of silly math, ciphers and asked a lot of my vintage hardware on this site over the years. But I’ve not talked a ton about optimizing code for faster results.
Today, we will count from 0 to 2^24-1 (16,777,215). Nothing else. Count, time it, and see how fast we can get it to go.
Rust In Rust on my 2020 MacBook Pro:
use std::time::{Instant}; fn main() { // Start timing let start = Instant::now(); // Loop from 0 to 16777215 for _i in 0.
November 21, 2023
A gentle introduction to two's complement
I was recently on a video call with a friend, throwing around some ideas for a new product. I mentioned adding large signed numbers in assembly and using two’s complement. He asked me what two’s complement was. I was a little surprised that he didn’t know. He’s been a Java programmer for more than 30 years. Java and Python programmers (and others like gasp Commodore / MicroSoft BASIC) don’t have a native unsigned integer type.
September 8, 2023
Rail Fence Cipher on Commoodore 64 and TI 99/4A
I have a BUNCH of nieces and nephews. Over the years, doing some secret message passing with them around birthdays and holidays has been fun.
The “secret” location of hidden Christmas presents is a favorite.
Traditionally, we’ve used a transposition cipher like the Shift or Ceasar Cipher
For something different, we’re going to use another transposition cipher called the Rail Fence Cipher. It is easy to implement and understand. Plus easy to break, so it’s a good teaching tool.
May 5, 2023
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 6502 speed series.
I have the latest model of this board, and he made an interesting design choice. It actually has an FTDI chip on board and you use that via USB to connect via a modern computer with an FTDI driver. This is very convenient for working with a modern computer, but then eliminates the ability to use a real serial port.