Mit dem Rwabs() Bios-Aufruf ist es ähnlich: die AI braucht mehr Kontext.
write a program for the atari st that reads sector number 5 from the bios device 2 using the Rwabs() Bios system call
The Atari ST operating system uses the BIOS (Basic Input/Output System) to interact with devices such as disk drives. To read sector number 5 from the BIOS device 2 using the Rwabs() BIOS system call, you can use the following program in assembly language:
section code
start:
move.l #2, d0 ; BIOS device number (2 = floppy drive)
move.l #5, d1 ; Sector number to read
move.l #1, d2 ; Number of sectors to read
move.l buffer, a1 ; Address of buffer to store data
move.w #512, d3 ; Number of bytes to read
move.w #0, d4 ; Read operation
trap #14 ; Rwabs() BIOS system call
tst.w d0 ; Check for errors
bmi.s error ; Branch to error handler if negative status
jmp.s done
error:
; Handle error
done:
; Continue execution
section data
buffer:
rmb 512 ; Reserve 512 bytes for the buffer
This program uses the Atari ST's Motorola 68000 assembly language and the BIOS system calls to access the BIOS.
It starts by loading the necessary parameters into registers. The device number is loaded into d0 (2=floppy drive), sector number is loaded into d1, number of sectors to read is loaded into d2 , address of buffer to store data is loaded into a1, number of bytes to read is loaded into d3, and the operation code is loaded into d4 (0 = read)
The trap #14 instruction is used to call the Rwabs() BIOS system call with these parameters, which will read the specified sector from the device and store it in the buffer. The contents of d0 will be updated with the status of the operation: if it's negative, it means an error has occurred. So the program check for errors using the tst.w d0 instruction and jumps to the error handl
Das ist immer noch nicht richtig (die Parameter sind verdreht, werden in Registern übergeben und die Stackkorrektur am Ende fehlt), aber schon deutlich näher dran. Ich habe auch vergessen, ein C-Programm zu verlangen und die AI hat von sich aus beschlossen, es mal in Assembler zu versuchen.
Offensichtlich muss man die richtige Antwort kennen, um die richtige Frage zu stellen.