z180/msgbuf.180

   1         page    255
   2         .z80
   3
   4         global  msg_fifo
   5         global  msginit
   6         global  msg.out,msg.sout,msg.co
   7
   8         extrn   buf.init
   9
  10         include config.inc
  11         include z180reg.inc
  12
  13 ;--------------------------------------------------------------
  14
  15         dseg
  16
  17         mkbuf   msg_fifo, 0
  18
  19
  20 ;--------------------------------------------------------------
  21
  22         cseg
  23
  24 ;
  25 ; Init buffer
  26 ;
  27
  28 msginit:
  29         ld      ix,msg_fifo
  30         ld      a,msg_fb_len-1
  31         jp      buf.init
  32
  33
  34 ;--------------------------------------------------------------
  35
  36 msg.sts:
  37         push    ix
  38         ld      ix,msg_fifo             ;
  39
  40         ld      a,(ix+o.in_idx)         ;
  41         inc     a
  42         and     (ix+o.mask)
  43         sub     (ix+o.out_idx)          ;
  44         pop     ix
  45         ret     z
  46         or      0ffh
  47         ret
  48
  49 ;--------------------------------------------------------------
  50
  51 msg.out:
  52         push    ix
  53         ld      ix,msg_fifo             ;
  54
  55         push    bc
  56         ld      b,a                     ;save char
  57         ld      a,(ix+o.in_idx)         ;
  58         inc     a
  59         and     (ix+o.mask)
  60 bp.wait:
  61         cp      (ix+o.out_idx)          ;
  62         jr      z,bp.wait
  63         ld      c,a
  64         ld      a,b
  65         out     (PMSG),a
  66         ld      (ix+o.in_idx),c
  67
  68         pop     bc
  69         pop     ix
  70         ret
  71
  72 ;--------------------------------------------------------------
  73 ;
  74 ; (hl): data
  75
  76 msg.sout:
  77         push    ix
  78         ld      ix,msg_fifo             ;
  79         push    bc
  80
  81         ld      b,(hl)                  ;count
  82         inc     hl
  83 obs_1:
  84         ld      a,(ix+o.out_idx)        ;
  85         sub     (ix+o.in_idx)           ;
  86         dec     a
  87         and     (ix+o.mask)
  88         cp      b
  89         jr      c,obs_1
  90
  91         ld      c,(hl)                  ;port address
  92         inc     hl
  93         ld      a,b
  94         otir
  95         add     (ix+o.in_idx)
  96         and     (ix+o.mask)
  97         ld      (ix+o.in_idx),a
  98         pop     bc
  99         pop     ix
 100         ret
 101
 102 ;----------------------------------------------------------------------
 103
 104 msg.co:
 105         push    af
 106         push    hl
 107         ld      (buf_char),a
 108         ld      hl,buf
 109         call    msg.sout
 110         pop     hl
 111         pop     af
 112         ret
 113
 114
 115 buf:
 116         db      buf_end - $ - 2         ;output string length
 117         db      PMSG                    ;output port
 118         db      081h                    ; message start token
 119         db      buf_end - $ - 1         ; message length
 120         db      1                       ; command
 121         db      1                       ; subcommand
 122 buf_char:
 123         db      0                       ; pay load
 124 buf_end:
 125
 126 ;----------------------------------------------------------------------
 127
 128         end
 129