On 25/11/2017 20:56, didier derny wrote: > the problem occurred on a replica 1 (original apple 1 monitor) > > I checked the monitor code no initialization of the stack > > my code was working fine on commodore and on a sym 1 > The world is full of code that worked on the programmers machine. The stack pointer wraps, so technically you don't need to initialise it. I would hazzard a guess that the Apple 1 just isn't sensitive to the starting value, so they don't bother to initialise it. But your code for some reason is sensitive. The commodore 64 kernal sets the stack pointer & they did a lot of rewriting to make it fit in the limited rom. So if it was unnecessary then it's 3 bytes they could have removed easily. ; RESET routine FCE2 A2 FF LDX #$FF FCE4 78 SEI FCE5 9A TXS FCE6 D8 CLD Message was sent through the cbm-hackers mailing listReceived on 2017-11-25 22:03:21
Archive generated by hypermail 2.2.0.