trs80: implement Grid shim in video driver

Loading the grid subsystem on top of the TRS-80 driver, which is
an interface to its ROM BIOS, would be counter-productive because
the BIOS already has the concept of cursor.

However, VE needs the Grid interface, so we implement a shim for it.

Again, all this work (and the re-assembly that it entails) has been
done from within Collapse OS on the TRS-80!
This commit is contained in:
Virgil Dupras 2020-12-22 18:22:06 -05:00
parent 625afba86a
commit 20c38e5cd0

View File

@ -29,6 +29,8 @@ CODE AT-XY EXX, ( protect BC )
EXX, ( unprotect BC ) ;CODE EXX, ( unprotect BC ) ;CODE
( ----- 604 ) ( ----- 604 )
: LINES 24 ; : COLS 80 ; : LINES 24 ; : COLS 80 ;
: XYMODE 0x70 RAM+ ;
: CELL! COLS /MOD AT-XY (emit) ;
CODE BYE CODE BYE
HL 0 LDdi, HL 0 LDdi,
A 0x16 LDri, ( @EXIT ) A 0x16 LDri, ( @EXIT )