avrcpm/cpm/ipl.asm

   1 ;    CP/M IPL for avrcpm
   2 ;    Copyright (C) 2010 Sprite_tm
   3 ;
   4 ;    This program is free software: you can redistribute it and/or modify
   5 ;    it under the terms of the GNU General Public License as published by
   6 ;    the Free Software Foundation, either version 3 of the License, or
   7 ;    (at your option) any later version.
   8 ;
   9 ;    This program is distributed in the hope that it will be useful,
  10 ;    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 ;    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 ;    GNU General Public License for more details.
  13 ;
  14 ;    You should have received a copy of the GNU General Public License
  15 ;    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 org $2000
  18         ; IPL for the CP/M-emu in an AVR. Loads CPM from the 'disk' from
  19         ; track 0 sector 2 to track 1 sector 26.
  20
  21         ld sp,$1000
  22
  23         call printipl
  24
  25
  26         ld b,49
  27         ld de,$0001
  28         ld hl,$3400+$A800
  29 loadloop:
  30         ld a,d ;track
  31         out (16),a
  32         ld a,e ; sector (base-0)
  33         out (18),a
  34         ld a,l ;dma L
  35         out (20),a
  36         ld a,h ;dma H
  37         out (21),a
  38         ld a,1
  39         out (22),a
  40
  41         push bc
  42         ld bc,$80
  43         add hl,bc
  44         pop bc
  45
  46         inc e
  47         ld a,e
  48         cp 26
  49         jp nz,noNextTrack
  50
  51         inc d
  52         ld e,0
  53
  54 noNextTrack:
  55
  56         dec b
  57         jp nz,loadloop
  58
  59         jp $4A00+$A800
  60
  61 printipl:
  62         ld a,'i'
  63         out (2),a
  64         ld a,'p'
  65         out (2),a
  66         ld a,'l'
  67         out (2),a
  68         ld a,13
  69         out (2),a
  70         ld a,10
  71         out (2),a
  72         ret
  73
  74 end