Lockar wrote:
How did the Laser 128 run Apple // programs if it didn't have any
code of Apple ROMS? (I know some programs do not work on the Laser).
If it was done the same way as in the early IBM PC clones, then for every commonly-used CALL (or JSR) into the ROM code there was something in the Laser ROMs that did the same thing as the original Apple routine at the same address, but employing different machine language sequences.
Of course for Apple this was more difficult to get working because there were such jump-in points throughout the ROM, unlike the IBM which used mostly "software interrupts", through jump vectors stored in RAM and thus not fixed.
The programs that don't work on the Laser are either those that jump into the ROM at less commonly used addresses for which the Laser doesn't provide the necessary code, or maybe a few that depend on exact cycle counts of certain ROM routines.
-- Linards Ticmanis