getting started in amiga assembly

[Piru]

What's the best assembler?

DevPac

Best documented?

Commercial: DevPac
Free: PhxAss

Is CygnusEd still a nice editor for code?

IMO yes.

How to call the OS functions?

1. open the library, store the library pointer somewhere
2. move the library pointer to a6 register
3. move function arguments to input registers
4. jsr to LVO offset (jsr -xxx(a6))
5. return value is returned in d0, if any
6. at program exit close the library

I'd be pretty happy to get some very basic "hello world" type assembly source

Code: [Select]


_LVOOpenLibrary EQU -552
_LVOCloseLibrary EQU -414
_LVOOutput EQU -60
_LVOWrite EQU -48

start:
  move.l  4.w,a6
  lea     dosname(pc),a1
  moveq   #0,d0
  jsr     _LVOOpenLibrary(a6)
  tst.l   d0
  beq.s   nodos
  move.l  d0,a6
  lea     msg(pc),a0
  moveq   #-1,d3
  move.l  a0,d2
strlen:
  addq.l  #1,d3
  tst.b   (a0)+
  bne.s   strlen
  jsr     _LVOOutput(a6)
  move.l  d0,d1
  jsr     _LVOWrite(a6)
  move.l  a6,a1
  move.l  4.w,a6
  jsr     _LVOCloseLibrary(a6)
nodos:
  moveq   #0,d0
  rts
dosname:
  dc.b 'dos.library',0
msg:
  dc.b 'Hello, world!',10,0