06-25-2026, 12:20 AM
I was confused as well. It seems that the limit is set in the OS in combination with POKEY and with a modified ROM and driver you can get 120k/bps. The 4.7k resistor and removing capacitors was to improve the reliability of high speed transfers. Stock components can reliably achieve 58k/bps, although the 1050 drive with the RIOT chip was limited to 19.2k. The Happy and other drive mods used a 6502 to replace the 6507 which was able to utilize the higher transfer rate. I gleamed a bit of this information from the Fujinet project and a Github repo HiassofT/highspeed-sio...