IBM PS/1 2121 ROM errata

The previously published ROM for the PS/1 2121 with no romdrive (20MHz model) is overdumped: it has 256KiB of data instead of the expected 128KiB (the additional 128KiB are a replica of the first half). Here’s a verified direct dump from the 1 Megabit AM27C1024 chip inside the PS/1 2121 20MHz: IBM PS1 2121 – […]