search

X16Community / x16-docs

Commander X16 Documentation (CC BY-SA)
88 stars 35 forks source link

Document contents of KERNAL NVRAM (IO programming), and update hardware pinout #211

Closed stople closed 1 month ago

stople commented 1 month ago

Documenting contents of KERNAL NVRAM, as I did not find this information documented elsewhere.

Information source:

x16-rom, rtc.s and screen.s

stople commented 1 month ago

Note that the "Unused" $4D/$5A byte seem to be used by the custom ROM used by the Calypso project, for mapping device 8, 9, 10 and 11 between "CBDOS/IEC" (SD-card) and Calypso. Not sure if this should be reflected in the official documentation, of if that is considered an unofficial hack.

EDIT: Ref Discord, smrobtzz prefers the Calypso config byte to be undocumented for now, and will rather document it later if the ROM changes becomes upstreamed. https://discord.com/channels/1184615628317929563/1216138534336073860/1271248342420291616

stople commented 1 month ago

While making a PR for updating hardware documentation, I also reviewed the hardware chapter and updated it according to the schematics. Let me know if I should split this into two different PRs.