[Dr_Jefyll]

Probably the second-best fun I ever had was reverse engineering a discrete-TTL processor and the firmware written for it. These were embedded in some Xerox Diablo daisy-wheel printers dating from the latter half of the 20th Century. And the best fun I ever had was hacking that code to better suit the unique needs of my customer!

I wrote about the Diablos and their multi-axis realtime motion control here [1]. The good stuff about the hacking starts just over halfway down the page, "the Diablo proprietary processor."

HN has honored me in past by recognizing other items on the site, such as "One-Bit Computing at 60 Hertz" [2] and "the KK Computer - a radical 6502 redesign" [3].

[1]https://laughtonelectronics.com/oldsite/comm_mfg/commercial_... [2]https://laughtonelectronics.com/Arcana/One-bit%20computer/On... [3]https://laughtonelectronics.com/Arcana/KimKlone/Kimklone_sho...