FF.CFG: write-drain = instant | realtime | eot

'eot' fixes Not Ready errors on large writes and disk copies to
Gotek on Amstrad PPC640/512.

Fixes #320

examples/FF.CFG

@@ -62,12 +62,19 @@ write-protect = no
 # Values: 0 <= N <= 255
 side-select-glitch-filter = 0
 
-# Rotational offset of data after a track change
+# Rotational offset of disk after a track change
 # instant: No rotation during track change
 # realtime: Emulate rotation of disk while track is changing
 # Values: instant | realtime
 track-change = instant
 
+# Rotational offset of disk after draining a write to Flash
+# instant: No rotation
+# realtime: Disk rotates in real time during drain
+# eot: Disk rotates to (near) end of track
+# Values: instant | realtime | eot
+write-drain = instant
+
 # Index pulses suppressed when RDATA and WDATA inactive?
 # Values: yes | no
 index-suppression = yes

inc/config.h

@@ -155,6 +155,10 @@ struct packed ff_cfg {
 #define DORD_row     7
 #define DORD_double  8
     uint16_t display_order;
+#define WDRAIN_instant  0
+#define WDRAIN_realtime 1
+#define WDRAIN_eot      2
+    uint8_t write_drain;
 };
 
 extern struct ff_cfg ff_cfg;

scripts/mk_config.py

@@ -25,6 +25,8 @@ def main(argv):
                 val = "PIN_" + val
             elif opt == "track-change":
                 val = "TRKCHG_" + val
+            elif opt == "write-drain":
+                val = "WDRAIN_" + val
             elif opt == "host":
                 val = "HOST_" + val
             elif opt == "oled-font":

src/floppy_generic.c

@@ -342,9 +342,21 @@ static void wdata_stop(void)
     /* Drain out the DMA buffer. */
     IRQx_set_pending(dma_wdata_irq);
 
-    /* Restart read exactly where write ended. 
-     * No more IDX pulses until write-out is complete. */
-    drive_set_restart_pos(drv);
+    switch (ff_cfg.write_drain) {
+    case WDRAIN_instant:
+        /* Restart read exactly where write ended. No more IDX pulses until
+         * write-out is complete. */
+        drive_set_restart_pos(drv);
+        break;
+    case WDRAIN_realtime:
+        /* Nothing to do. */
+        break;
+    case WDRAIN_eot:
+        /* Position so that an INDEX pulse is quickly triggered. */
+        drv->restart_pos = drv->image->stk_per_rev - stk_ms(20);
+        drv->index_suppressed = TRUE;
+        break;
+    }
 
     /* Remember where this write's DMA stream ended. */
     write = get_write(image, image->wr_prod);
@@ -359,6 +371,7 @@ static void wdata_stop(void)
         IRQx_set_pending(FLOPPY_SOFTIRQ);
         /* Position read head so it quickly triggers an INDEX pulse. */
         drv->restart_pos = drv->image->stk_per_rev - stk_ms(20);
+        drv->index_suppressed = TRUE;
     }
 #endif
 }

src/main.c

@@ -932,6 +932,13 @@ static void read_ff_cfg(void)
                 : TRKCHG_instant;
             break;
 
+        case FFCFG_write_drain:
+            ff_cfg.write_drain =
+                !strcmp(opts.arg, "realtime") ? WDRAIN_realtime
+                : !strcmp(opts.arg, "eot") ? WDRAIN_eot
+                : WDRAIN_instant;
+            break;
+
         case FFCFG_index_suppression:
             ff_cfg.index_suppression = !strcmp(opts.arg, "yes");
             break;