Only read drive data while spinning

diff --git a/src/drive.c b/src/drive.c
index e74b64dfe995024f78d5904ef2b04e6ec134f6ff..8eb1bfdf0848fcf429ca580e1312423b64ac1e01 100644 (file)
--- a/src/drive.c
+++ b/src/drive.c
@@ -110,85 +110,87 @@ bool drive_cycle(drive_t *drive, uint8_t cycles, bool advance) {
 
                                drive->gcr_bits = 10;
                                */
-                               if (drive->gap_remain > 0) {
-                                       drive->gap_remain--;
-                                       drive->gcr_word = 0x55;
-                                       drive->gcr_bits = 8;
-                               } else if (drive->sync_remain > 0) {
-                                       drive->sync_remain--;
-                                       drive->gcr_word = 0x3ff;
-                                       drive->gcr_bits = 10;
-                               } else if (drive->header_remain > 0) {
-                                       drive->header_remain--;
-                                       uint8_t track_plus_one = drive->track + 1;
-                                       uint8_t checksum = drive->sector ^ track_plus_one;
-                                       switch (drive->header_remain) {
-                                       case 7:
-                                               drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0x8];
-                                               break;
-                                       case 6:
-                                               drive->gcr_word = (GCR_CONV[(checksum & 0xf0) >> 4] << 5) | GCR_CONV[checksum & 0x0f];
-                                               break;
-                                       case 5:
-                                               drive->gcr_word = (GCR_CONV[(drive->sector & 0xf0) >> 4] << 5) | GCR_CONV[drive->sector & 0x0f];
-                                               break;
-                                       case 4:
-                                               drive->gcr_word = (GCR_CONV[(track_plus_one & 0xf0) >> 4] << 5) | GCR_CONV[track_plus_one & 0x0f];
-                                               break;
-                                       case 3:
-                                       case 2:
-                                               drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0x0];
-                                               break;
-                                       case 1:
-                                       case 0:
-                                               drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0xf];
-                                               break;
-                                       }
-                                       if (drive->header_remain == 0) {
-                                               drive->gap_remain = 9;
-                                               drive->sync_remain = 4;
-                                               drive->data_remain = 260;
-                                               drive->data_checksum = 0;
-                                       }
-                                       drive->gcr_bits = 10;
-                               } else if (drive->data_remain > 0) {
-                                       drive->data_remain--;
-                                       switch (drive->data_remain) {
-                                       case 259:
-                                               drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0x7];
-                                               break;
-                                       case 2:
-                                               drive->gcr_word = (GCR_CONV[(drive->data_checksum & 0xf0) >> 4] << 5) | GCR_CONV[drive->data_checksum & 0x0f];
-                                               break;
-                                       case 1:
-                                       case 0:
-                                               drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0xf];
-                                               break;
-                                       default:
-                                               {
-                                                       uint8_t b = drive->image[drive->image_ptr + (drive->sector << 8) + drive->byte];
-                                                       drive->gcr_word = (GCR_CONV[(b & 0xf0) >> 4] << 5) | GCR_CONV[b & 0x0f];
-                                                       drive->data_checksum ^= b;
-
-                                                       uint8_t byte_next = drive->byte + 1;
-                                                       uint8_t sector_next = drive->sector;
-                                                       if (byte_next == 0) {
-                                                               sector_next += 1;
-                                                       }
-                                                       if (sector_next >= SECTORS_PER_TRACK[drive->track]) {
-                                                               sector_next = 0;
+                               if (drive->spinning) {
+                                       if (drive->gap_remain > 0) {
+                                               drive->gap_remain--;
+                                               drive->gcr_word = 0x55;
+                                               drive->gcr_bits = 8;
+                                       } else if (drive->sync_remain > 0) {
+                                               drive->sync_remain--;
+                                               drive->gcr_word = 0x3ff;
+                                               drive->gcr_bits = 10;
+                                       } else if (drive->header_remain > 0) {
+                                               drive->header_remain--;
+                                               uint8_t track_plus_one = drive->track + 1;
+                                               uint8_t checksum = drive->sector ^ track_plus_one;
+                                               switch (drive->header_remain) {
+                                               case 7:
+                                                       drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0x8];
+                                                       break;
+                                               case 6:
+                                                       drive->gcr_word = (GCR_CONV[(checksum & 0xf0) >> 4] << 5) | GCR_CONV[checksum & 0x0f];
+                                                       break;
+                                               case 5:
+                                                       drive->gcr_word = (GCR_CONV[(drive->sector & 0xf0) >> 4] << 5) | GCR_CONV[drive->sector & 0x0f];
+                                                       break;
+                                               case 4:
+                                                       drive->gcr_word = (GCR_CONV[(track_plus_one & 0xf0) >> 4] << 5) | GCR_CONV[track_plus_one & 0x0f];
+                                                       break;
+                                               case 3:
+                                               case 2:
+                                                       drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0x0];
+                                                       break;
+                                               case 1:
+                                               case 0:
+                                                       drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0xf];
+                                                       break;
+                                               }
+                                               if (drive->header_remain == 0) {
+                                                       drive->gap_remain = 9;
+                                                       drive->sync_remain = 4;
+                                                       drive->data_remain = 260;
+                                                       drive->data_checksum = 0;
+                                               }
+                                               drive->gcr_bits = 10;
+                                       } else if (drive->data_remain > 0) {
+                                               drive->data_remain--;
+                                               switch (drive->data_remain) {
+                                               case 259:
+                                                       drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0x7];
+                                                       break;
+                                               case 2:
+                                                       drive->gcr_word = (GCR_CONV[(drive->data_checksum & 0xf0) >> 4] << 5) | GCR_CONV[drive->data_checksum & 0x0f];
+                                                       break;
+                                               case 1:
+                                               case 0:
+                                                       drive->gcr_word = (GCR_CONV[0x0] << 5) | GCR_CONV[0xf];
+                                                       break;
+                                               default:
+                                                       {
+                                                               uint8_t b = drive->image[drive->image_ptr + (drive->sector << 8) + drive->byte];
+                                                               drive->gcr_word = (GCR_CONV[(b & 0xf0) >> 4] << 5) | GCR_CONV[b & 0x0f];
+                                                               drive->data_checksum ^= b;      
+
+                                                               uint8_t byte_next = drive->byte + 1;
+                                                               uint8_t sector_next = drive->sector;
+                                                               if (byte_next == 0) {
+                                                                       sector_next += 1;
+                                                               }
+                                                               if (sector_next >= SECTORS_PER_TRACK[drive->track]) {
+                                                                       sector_next = 0;
+                                                               }
+                                                               drive->byte = byte_next;
+                                                               drive->sector = sector_next;
                                                        }
-                                                       drive->byte = byte_next;
-                                                       drive->sector = sector_next;
+                                                       break;
                                                }
-                                               break;
-                                       }
-                                       if (drive->data_remain == 0) {
-                                               drive->gap_remain = 10;
-                                               drive->sync_remain = 4;
-                                               drive->header_remain = 8;
+                                               if (drive->data_remain == 0) {
+                                                       drive->gap_remain = 10;
+                                                       drive->sync_remain = 4;
+                                                       drive->header_remain = 8;
+                                               }
+                                               drive->gcr_bits = 10;
                                        }
-                                       drive->gcr_bits = 10;
                                }
                        }