GUIDEALPHA · USE AT YOUR OWN RISK
Assembly guide
Call EGFX safely from a BBC Micro program, locally or through the Tube.
1 · Transport
Use MOS OSWORD &C0. It works on the host or an Acorn 6502 parasite without sharing pointers.
2 · Request block
LDA #&C0
LDX #block MOD 256:LDY #block DIV 256
JSR &FFF1
; block+7 = &A5 on success3 · Frame loop
Call INIT once, then BEGIN, drawing functions and PRESENT for each frame.
4 · Direct calls
Direct local callers must save MOS ROM state, select the EGFX slot through &FE30, call the entry, then restore state. OSWORD is recommended.