[Coco] Page zero variables (CoCoSDC - PING Darren)

[Juan Castro]

HDB-DOS leaves exactly three bytes free at the end of page zero. Does the
CoCoSDC DECB use these for some purpose?

I want to hack the ECB on a CoCo 2B so I can have a setting for border and
lowercase in text mode. I can just replace the ANDA #$07 at $95C8 with ANDA
#$57, but then whenever I go to graphics mode and back I go back to
lowercase and green borders. My plan is reserve a byte variable having the
value to be OR'ed with PIA1+2 after ANDing with #$07.

And while I'm at it I could invent a setting for orange screen too.

Juan Castro
Enviado do meu Olivetti Programma 101