bsv.c

   1 #include <stdio.h>
   2 #include "fakeasm.h"
   3 typedef unsigned char u8;
   4
   5 u8 notes[16]; //MEM
   6 u8 i0, i1, i2; //MEM
   7 u8 n; //MEM
   8 u8 sample; //MEM
   9 u8 tmp_1; //MEM
  10 u8 acc; //ACC
  11
  12 u8 mod3hi, mod3lo; //MEM
  13 //todo: can mod3hi be aliased to tmp_1?
  14 void mod3(void) {
  15         MOV     (acc,mod3hi)
  16         ADD     (mod3lo,acc) // mod3lo = hi+lo
  17         CLEAR   (acc)
  18         ADDC0   (acc) // mod3hi, 1bit
  19         SWAP    (acc)
  20         MOV     (mod3hi, acc)
  21
  22         MOV     (acc, mod3lo)
  23         SWAP    (acc)
  24         AND     (acc, 0xf) // (mod3lo>>4)
  25         XCH     (mod3lo) // acc=mod3lo, mod3lo=mod3lo>>4
  26         AND     (acc, 0xF) // acc=mod3lo&0xf, mod3lo=mod3lo>>4
  27         ADD     (acc, mod3lo) // (mod3lo & 0xF)
  28         ADD     (acc, mod3hi)
  29         MOV     (mod3lo, acc)
  30
  31         AND     (acc, 0x3) // acc = (mod3lo & 0x3)
  32         SR      (mod3lo)
  33         SR      (mod3lo) // (mod3lo >>  2)
  34         ADD     (acc, mod3lo)
  35         MOV     (mod3lo, acc)
  36
  37         AND     (acc, 0x3) // acc = (mod3lo & 0x3)
  38         SR      (mod3lo)
  39         SR      (mod3lo) // (mod3lo >>  2)
  40         ADD     (acc, mod3lo)
  41
  42         SUB     (acc,3)
  43         /*T0SN  FLAG.C (0x00.1)*/       if (flag_c){ // skip if carry clear
  44         ADD (acc,3)                     }
  45 }
  46
  47 void g(void){
  48         // notes_ix_hi = always 0
  49         u8 notes_ix;//lo
  50         AND     (acc, 0x7)
  51         MOV     (notes_ix, acc)
  52         // test i2 & 3:
  53         MOV     (acc, i2)
  54         AND     (acc, 3)
  55         /*T0SN  FLAG.Z (0x00.0)*/       if(3&i2) {// skip if !(3&i0)
  56         SET1    (notes_ix, 3)           } // ix += 8 <=> ix |= 8
  57         IDXM    (acc, notes+notes_ix)
  58         u8 result = ((i1<<8|i0)*acc)>>8;  // keep hi byte
  59         //^TODO!
  60         acc = result;
  61 }
  62 void main(void){
  63         CLEAR   (i0)
  64         CLEAR   (i1)
  65         CLEAR   (i2)
  66
  67         //rom is not mmapped; must load into ram first
  68         MOV     (acc, 0x84)
  69         MOV     (notes[0x0], acc)
  70         MOV     (notes[0x5], acc)
  71         MOV     (acc, 0x9d)
  72         MOV     (notes[0x1], acc)
  73         MOV     (notes[0x4], acc)
  74         MOV     (acc, 0xb0)
  75         MOV     (notes[0x2], acc)
  76         MOV     (notes[0xA], acc)
  77         MOV     (acc, 0x69)
  78         MOV     (notes[0x3], acc)
  79         MOV     (notes[0x6], acc)
  80         MOV     (notes[0xB], acc)
  81         MOV     (notes[0xE], acc)
  82         MOV     (acc, 0x58)
  83         MOV     (notes[0x7], acc)
  84         MOV     (notes[0xF], acc)
  85         MOV     (acc, 0x75)
  86         MOV     (notes[0x8], acc)
  87         MOV     (notes[0xD], acc)
  88         MOV     (acc, 0x8c)
  89         MOV     (notes[0x9], acc)
  90         MOV     (notes[0xC], acc)
  91
  92         for(;;) {
  93                 MOV     (acc, i2)// "mov mem,mem"
  94                 MOV     (n, acc)// does not exist
  95                 SL      (n)
  96                 SL      (n)
  97                 MOV     (acc, i1)
  98                 SWAP    (acc)
  99                 AND     (acc, 0xf)
 100                 SR      (acc)
 101                 SR      (acc)
 102                 OR      (n, acc)
 103
 104                 MOV     (acc, n)
 105                 CALL    (g)
 106                 SWAP    (acc)
 107                 AND     (acc, 0x1)
 108                 MOV     (sample, acc)
 109
 110                 MOV     (acc, i2)
 111                 SL      (acc)
 112                 SL      (acc)
 113                 SL      (acc)
 114                 MOV     (tmp_1, acc) // fresh tmp_1:
 115                 MOV     (acc, i1)
 116                 SWAP    (acc)
 117                 AND     (acc, 0xf)
 118                 SR      (acc)
 119                 OR      (acc, tmp_1) // tmp_1 done.
 120                 XOR     (acc, n)
 121                 CALL    (g)
 122                 SR      (acc)
 123                 AND     (acc, i2)
 124                 SR      (acc)
 125                 AND     (acc, 3)
 126                 ADD     (sample, acc)
 127
 128                 MOV     (acc, i2)
 129                 MOV     (mod3hi, acc)
 130                 SR      (mod3hi)
 131                 SR      (mod3hi)
 132                 SR      (mod3hi)
 133                 SWAP    (acc)
 134                 AND     (acc, 0xf0)
 135                 SL      (acc)
 136                 MOV     (mod3lo, acc)
 137                 MOV     (acc, i1)
 138                 SR      (acc)
 139                 SR      (acc)
 140                 SR      (acc)
 141                 OR      (mod3lo, acc)
 142                 CALL    (mod3)
 143                 ADD     (acc, n)
 144                 CALL    (g)
 145                 SR      (acc)
 146                 SR      (acc)
 147                 MOV     (tmp_1, acc) // acc saved in tmp_1; fresh acc
 148                 MOV     (acc, i2)
 149                 // shift-divide by six
 150                 // note: i2 is max 0x78; so acc will <= 20. (breaks vor values >=128)
 151                 SR      (acc)
 152                 ADD     (acc, i2)
 153                 SR      (acc)
 154                 SR      (acc)
 155                 ADD     (acc, i2)
 156                 SR      (acc)
 157                 SR      (acc)
 158                 ADD     (acc, i2)
 159                 SR      (acc)
 160                 SR      (acc)
 161                 SR      (acc)
 162                 // end divide by six
 163                 AND     (acc, tmp_1) // acc restored from tmp_1
 164                 AND     (acc, 3)
 165                 ADD     (sample, acc)
 166
 167                 MOV     (acc, i2)
 168                 MOV     (mod3hi, acc)
 169                 SR      (mod3hi)
 170                 SR      (mod3hi)
 171                 SWAP    (acc)
 172                 AND     (acc, 0xf0)
 173                 SL      (acc)
 174                 SL      (acc)
 175                 MOV     (mod3lo, acc)
 176                 MOV     (acc, i1)
 177                 SR      (acc)
 178                 SR      (acc)
 179                 OR      (mod3lo, acc)
 180                 CALL    (mod3)
 181                 SUB     (acc, n)
 182                 SUB     (acc, 8)
 183                 NEG     (acc)
 184                 CALL    (g)
 185                 SR      (acc)
 186                 MOV     (tmp_1, acc) // acc saved in tmp_1; fresh acc
 187                 MOV     (acc, i2)
 188                 // shift-divide by ten
 189                 // note: i2 is max 0x78; so acc will <= 12.
 190                 INC     (i2)
 191                 SR      (acc)
 192                 ADD     (acc, i2)
 193                 SR      (acc)
 194                 SR      (acc)
 195                 SR      (acc)
 196                 ADD     (acc, i2)
 197                 SR      (acc)
 198                 ADD     (acc, i2)
 199                 SWAP    (acc)
 200                 DEC     (i2)
 201                 // end divide by ten
 202                 AND     (acc, tmp_1) // acc restored from tmp_1
 203                 AND     (acc, 3)
 204                 ADD     (sample, acc)
 205
 206                 MOV     (acc, sample)
 207                 SWAP    (acc)
 208                 putchar(acc);
 209
 210                 INC     (i0)
 211                 /*ADDC  i1*/            i1 += !i0;
 212                 /*ADDC  i2*/            i2 += !i1 && !i0;
 213
 214                 if(i2 == 0x78) break;
 215         }
 216 }