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Added a variety of checks and automatic repairs to DiskDump, aimed primarily at issues I've come across with pre-DOS 2.0 diskettes (eg, diskettes without BPBs, like 160Kb diskettes from DOS 1.0 and 320Kb diskettes from DOS 1.1)

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Jeff 2016-10-27 17:59:20 -07:00 • committed by Jeff Parsons
commit 88b485d094
4 changed files with 179 additions and 61 deletions
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18
modules/shared/lib/diskapi.js
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@ -73,21 +73,21 @@ var DiskAPI = {
*
* For no particular reason that I can recall, each entry in DISK_FORMATS is an array of values in "CHS" order:
*
* [# cylinders, # heads, # sectors/track, # bytes/sector]
* [# cylinders, # heads, # sectors/track, # bytes/sector, media type]
*
* If the 4th value is omitted, the sector size is assumed to be 512. The order of these "geometric" values mirrors
* the structure of our JSON-encoded disk images, which consist of an array of cylinders, each of which is an array of
* heads, each of which is an array of sector objects.
*/
DiskAPI.DISK_FORMATS = {
163840: [40,1,8], // media type 0xFE: 40 cylinders, 1 head (single-sided), 8 sectors/track, ( 320 total sectors x 512 bytes/sector == 163840)
184320: [40,1,9], // media type 0xFC: 40 cylinders, 1 head (single-sided), 9 sectors/track, ( 360 total sectors x 512 bytes/sector == 184320)
327680: [40,2,8], // media type 0xFF: 40 cylinders, 2 heads (double-sided), 8 sectors/track, ( 640 total sectors x 512 bytes/sector == 327680)
368640: [40,2,9], // media type 0xFD: 40 cylinders, 2 heads (double-sided), 9 sectors/track, ( 720 total sectors x 512 bytes/sector == 368640)
737280: [80,2,9], // media type 0xF9: 80 cylinders, 2 heads (double-sided), 9 sectors/track, (1440 total sectors x 512 bytes/sector == 737280)
1228800: [80,2,15], // media type 0xF9: 80 cylinders, 2 heads (double-sided), 15 sectors/track, (2400 total sectors x 512 bytes/sector == 1228800)
1474560: [80,2,18], // media type 0xF0: 80 cylinders, 2 heads (double-sided), 18 sectors/track, (2880 total sectors x 512 bytes/sector == 1474560)
2949120: [80,2,36], // media type 0xF0: 80 cylinders, 2 heads (double-sided), 36 sectors/track, (5760 total sectors x 512 bytes/sector == 2949120)
163840: [40,1,8,,0xFE], // media type 0xFE: 40 cylinders, 1 head (single-sided), 8 sectors/track, ( 320 total sectors x 512 bytes/sector == 163840)
184320: [40,1,9,,0xFC], // media type 0xFC: 40 cylinders, 1 head (single-sided), 9 sectors/track, ( 360 total sectors x 512 bytes/sector == 184320)
327680: [40,2,8,,0xFF], // media type 0xFF: 40 cylinders, 2 heads (double-sided), 8 sectors/track, ( 640 total sectors x 512 bytes/sector == 327680)
368640: [40,2,9,,0xFD], // media type 0xFD: 40 cylinders, 2 heads (double-sided), 9 sectors/track, ( 720 total sectors x 512 bytes/sector == 368640)
737280: [80,2,9,,0xF9], // media type 0xF9: 80 cylinders, 2 heads (double-sided), 9 sectors/track, (1440 total sectors x 512 bytes/sector == 737280)
1228800: [80,2,15,,0xF9], // media type 0xF9: 80 cylinders, 2 heads (double-sided), 15 sectors/track, (2400 total sectors x 512 bytes/sector == 1228800)
1474560: [80,2,18,,0xF0], // media type 0xF0: 80 cylinders, 2 heads (double-sided), 18 sectors/track, (2880 total sectors x 512 bytes/sector == 1474560)
2949120: [80,2,36,,0xF0], // media type 0xF0: 80 cylinders, 2 heads (double-sided), 36 sectors/track, (5760 total sectors x 512 bytes/sector == 2949120)
/*
* The following are common early hard drive sizes, which we explicitly map to CHS values, since the BPB can mislead us when attempting to calculate total cylinders
*/