gw read/write/convert: New option --reverse to reverse track data for…

… flippy disks

Examples:
gw convert --tracks=h=0:hswap --reverse a.scp a_side1.scp
gw convert --tracks=h=0:hswap --reverse a.scp a_side1.do
gw read --tracks=c=0-39:h=0:hswap --reverse a_side1.do
gw write --tracks=hswap --reverse a_side1.do

Refs #460

src/greaseweazle/flux.py

@@ -130,6 +130,31 @@ def cue_at_index(self) -> None:
             self.sector_list = self.sector_list[1:]
 
 
+    def reverse(self) -> None:
+
+        assert self.sector_list is None
+
+        was_index_cued = self.index_cued
+        flux_sum = sum(self.list)
+
+        self.index_cued = False
+        self.list.reverse()
+        self.index_list.reverse()
+
+        to_index = flux_sum - sum(self.index_list)
+        if to_index <= 0:
+            if to_index < 0:
+                self.list.insert(0, -to_index)
+                flux_sum += -to_index
+            self.index_list = self.index_list[1:]
+            self.index_cued = True
+        else:
+            self.index_list = [to_index] + self.index_list[:-1]
+
+        if was_index_cued:
+            self.index_list.append(flux_sum - sum(self.index_list))
+
+
     def set_nr_revs(self, revs:int) -> None:
 
         self.cue_at_index()

src/greaseweazle/tools/convert.py

@@ -49,6 +49,10 @@ def process_input_track(
     if track is None:
         return None
 
+    if args.reverse:
+        track = track.flux()
+        track.reverse()
+
     if args.hard_sectors:
         track = track.flux()
         track.identify_hard_sectors()
@@ -132,6 +136,8 @@ def main(argv) -> None:
                         help="manual PLL parameter override")
     parser.add_argument("--hard-sectors", action="store_true",
                         help="convert index positions to hard sectors")
+    parser.add_argument("--reverse", action="store_true",
+                        help="reverse track data (flippy disk)")
     parser.add_argument("in_file", help="input filename")
     parser.add_argument("out_file", help="output filename")
     parser.description = description

src/greaseweazle/tools/read.py

@@ -43,6 +43,8 @@ def read_and_normalise(usb: USB.Unit, args, revs: int, ticks=0) -> Flux:
     else:
         flux = usb.read_track(revs=revs, ticks=ticks)
     flux._ticks_per_rev = args.drive_ticks_per_rev
+    if args.reverse:
+        flux.reverse()
     if args.adjust_speed is not None:
         flux.scale(args.adjust_speed / flux.time_per_rev)
     return flux
@@ -211,6 +213,8 @@ def main(argv) -> None:
                         help="manual PLL parameter override")
     parser.add_argument("--densel", "--dd", type=util.level, metavar="LEVEL",
                         help="drive interface density select on pin 2 (H,L)")
+    parser.add_argument("--reverse", action="store_true",
+                        help="reverse track data (flippy disk)")
     parser.add_argument("file", help="output filename")
     parser.description = description
     parser.prog += ' ' + argv[1]

src/greaseweazle/tools/write.py

@@ -69,8 +69,14 @@ def write_from_image(usb: USB.Unit, args, image: image.Image) -> None:
         if isinstance(track, codec.Codec):
             track = track.master_track()
 
-        if args.precomp is not None and isinstance(track, MasterTrack):
-            track.precomp = args.precomp.track_precomp(cyl)
+        if isinstance(track, MasterTrack):
+            if args.reverse:
+                track.reverse()
+            if args.precomp is not None:
+                track.precomp = args.precomp.track_precomp(cyl)
+        elif args.reverse:
+            track = track.flux()
+            track.reverse()
         wflux = track.flux_for_writeout(cue_at_index = not no_index)
 
         # @factor adjusts flux times for speed variations between the
@@ -127,6 +133,8 @@ def write_from_image(usb: USB.Unit, args, image: image.Image) -> None:
             else:
                 v_flux = usb.read_track(revs = v_revs, ticks = v_ticks)
             v_flux._ticks_per_rev = drive_ticks_per_rev
+            if args.reverse:
+                v_flux.reverse()
             verified = verify.verify_track(v_flux)
             if verified:
                 verified_count += 1
@@ -205,6 +213,8 @@ def main(argv) -> None:
                         help="number of retries on verify failure")
     parser.add_argument("--precomp", type=PrecompSpec,
                         help="write precompensation")
+    parser.add_argument("--reverse", action="store_true",
+                        help="reverse track data (flippy disk)")
     densel_group = parser.add_mutually_exclusive_group(required=False)
     densel_group.add_argument(
         "--densel", "--dd", type=util.level, metavar="LEVEL",

src/greaseweazle/track.py

@@ -149,6 +149,17 @@ def summary_string(self) -> str:
         s += ')'
         return s
 
+    def reverse(self) -> None:
+        bitlen = len(self.bits)
+        if bitlen == 0: return
+        self.bits.reverse()
+        if self.bit_ticks is not None:
+            self.bit_ticks.reverse()
+        self.splice = -self.splice % bitlen
+        self.weak = list(map(lambda x: (-x[0] % bitlen, x[1]), self.weak))
+        if self.hardsector_bits is not None:
+            self.hardsector_bits.reverse()
+
     def flux(self, revs: Optional[int] = None) -> Flux:
         flux = self._flux(for_writeout=False, cue_at_index=True, revs=revs)
         assert isinstance(flux, Flux)