Hi, I am working on an assembly program that involves the serial port hook at F5FC.
The current code I have works by setting a JMP there to my data-received handler and then just returning. This is fine, but so far as I can tell from disassembling the ROM handler at 6DAC, after I return, the whole rest of the ROM's handler *also* runs. The program doesn't execute incorrectly since I've already got the data but I'm not suffering through writing assembly because I enjoy wasting lots of cycles. Now it seemed to me that since it gets to my code by call 0034 due to IRQ jmp 6DAC call F5FC (immediately at 6DAC) jmp $mycode, I should be able to INX SP twice to "delete" the return-to-rom address such that when I do RET it will return from the IRQ instead, thereby sidelining the ROM code completely. Except if I do this I am pointedly reminded that the 8085 does not have protected mode. And so my question: er... what exactly am I doing wrong here? -- Erik
