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Changed the "Adventures in Math (1983)" demo to boot PC-DOS 1.0 -- which in turn required a 160Kb disk image for the game

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Jeff Parsons 2017-06-14 16:02:03 -07:00 • committed by Jeff Parsons
commit f8eeed79bf
6 changed files with 95 additions and 38 deletions
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55
modules/diskdump/lib/diskdump.js
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@ -407,7 +407,7 @@ DiskDump.sUsage = "Usage: " + DiskDump.sAPIURL + "?" + DumpAPI.QUERY.PATH + "={u
* PCJS_LABEL is our default label, used whenever a more suitable label (eg, the disk image's folder name)
* is not available or not supplied, and PCJS_OEM is inserted into any DiskDump-generated diskette images.
*/
DiskDump.PCJS_LABEL = "PCJSDISK";
DiskDump.PCJS_LABEL = "PCJS.ORG";
DiskDump.PCJS_OEM = "PCJS.ORG";
/**
@ -431,26 +431,10 @@ DiskDump.aDefaultBPBs = [
0x01, 0x00, // 0x1A: number of heads (1)
0x00, 0x00, 0x00, 0x00 // 0x1C: number of hidden sectors (always 0 for non-partitioned media)
],
[ // define BPB for 180Kb diskette
0xEB, 0xFE, 0x90, // 0x00: JMP instruction, following by 8-byte OEM signature
0x50, 0x43, 0x4A, 0x53, 0x2E, 0x4F, 0x52, 0x47, // PCJS_OEM
// 0x49, 0x42, 0x4D, 0x20, 0x20, 0x31, 0x2E, 0x30, // "IBM 1.0" (this is a fake OEM signature)
0x00, 0x02, // 0x0B: bytes per sector (0x200 or 512)
0x01, // 0x0D: sectors per cluster (1)
0x01, 0x00, // 0x0E: reserved sectors; ie, # sectors preceding the first FAT--usually just the boot sector (1)
0x02, // 0x10: FAT copies (2)
0x40, 0x00, // 0x11: root directory entries (0x40 or 64) 0x40 * 0x20 = 0x800 (1 sector is 0x200 bytes, total of 4 sectors)
0x68, 0x01, // 0x13: number of sectors (0x168 or 360)
0xFC, // 0x15: media type (eg, 0xFF: 320Kb, 0xFE: 160Kb, 0xFD: 360Kb, 0xFC: 180Kb)
0x02, 0x00, // 0x16: sectors per FAT (2)
0x09, 0x00, // 0x18: sectors per track (9)
0x01, 0x00, // 0x1A: number of heads (1)
0x00, 0x00, 0x00, 0x00 // 0x1C: number of hidden sectors (always 0 for non-partitioned media)
],
[ // define BPB for 320Kb diskette
0xEB, 0xFE, 0x90, // 0x00: JMP instruction, following by 8-byte OEM signature
0x50, 0x43, 0x4A, 0x53, 0x2E, 0x4F, 0x52, 0x47, // PCJS_OEM
// 0x49, 0x42, 0x4D, 0x20, 0x20, 0x32, 0x2E, 0x30, // "IBM 2.0" (this is a real OEM signature)
// 0x49, 0x42, 0x4D, 0x20, 0x20, 0x31, 0x2E, 0x30, // "IBM 1.0" (this is a real OEM signature)
0x00, 0x02, // 0x0B: bytes per sector (0x200 or 512)
0x02, // 0x0D: sectors per cluster (2)
0x01, 0x00, // 0x0E: reserved sectors; ie, # sectors preceding the first FAT--usually just the boot sector (1)
@ -463,6 +447,22 @@ DiskDump.aDefaultBPBs = [
0x02, 0x00, // 0x1A: number of heads (2)
0x00, 0x00, 0x00, 0x00 // 0x1C: number of hidden sectors (always 0 for non-partitioned media)
],
[ // define BPB for 180Kb diskette
0xEB, 0xFE, 0x90, // 0x00: JMP instruction, following by 8-byte OEM signature
0x50, 0x43, 0x4A, 0x53, 0x2E, 0x4F, 0x52, 0x47, // PCJS_OEM
// 0x49, 0x42, 0x4D, 0x20, 0x20, 0x32, 0x2E, 0x30, // "IBM 2.0" (this is a fake OEM signature)
0x00, 0x02, // 0x0B: bytes per sector (0x200 or 512)
0x01, // 0x0D: sectors per cluster (1)
0x01, 0x00, // 0x0E: reserved sectors; ie, # sectors preceding the first FAT--usually just the boot sector (1)
0x02, // 0x10: FAT copies (2)
0x40, 0x00, // 0x11: root directory entries (0x40 or 64) 0x40 * 0x20 = 0x800 (1 sector is 0x200 bytes, total of 4 sectors)
0x68, 0x01, // 0x13: number of sectors (0x168 or 360)
0xFC, // 0x15: media type (eg, 0xFF: 320Kb, 0xFE: 160Kb, 0xFD: 360Kb, 0xFC: 180Kb)
0x02, 0x00, // 0x16: sectors per FAT (2)
0x09, 0x00, // 0x18: sectors per track (9)
0x01, 0x00, // 0x1A: number of heads (1)
0x00, 0x00, 0x00, 0x00 // 0x1C: number of hidden sectors (always 0 for non-partitioned media)
],
[ // define BPB for 360Kb diskette
0xEB, 0xFE, 0x90, // 0x00: JMP instruction, following by 8-byte OEM signature
0x50, 0x43, 0x4A, 0x53, 0x2E, 0x4F, 0x52, 0x47, // PCJS_OEM
@ -1903,7 +1903,7 @@ DiskDump.prototype.buildVolLabel = function(sDir)
}
}
}
if (!sVolume) {
if (!sVolume || sVolume.toLowerCase() == "archive" || sVolume.toLowerCase() == "disk") {
sVolume = DiskDump.PCJS_LABEL;
}
if (sVolume && sVolume.length <= 11) {
@ -2375,13 +2375,22 @@ DiskDump.prototype.buildImageFromFiles = function(aFiles, done)
* Find or build a BPB with enough capacity, and at the same time, calculate all the other values we'll need,
* including total number of data sectors (cDataSectors).
*
* TODO: For now, the code that chooses a default BPB is starting with #3 instead of #0, because Windows 95
* TODO: For now, the code that chooses a default BPB starts with entry #3 instead of #0, because Windows 95
* (at least when running under VMware) fails to read the contents of such disks correctly. Whether that's my
* fault or Windows 95's fault is still TBD (although it's probably mine -- perhaps 160Kb diskettes aren't
* supposed to have BPBs?) The simple work-around is to avoid creating 160Kb diskette images (and, to play it
* safe, I skip 180Kb and 320Kb as well, since 360Kb was the most commonly used format after DOS 2.0 introduced it).
* supposed to have BPBs?) The simple work-around is to avoid creating 160Kb diskette images used by PC-DOS 1.0.
* To play it safe, I also skip the 320Kb format (added for PC-DOS 1.1). 360Kb was the most commonly used format
* after PC-DOS 2.0 introduced it. PC-DOS 2.0 also introduced 180Kb (a single-sided version of the 360Kb
* double-sided format), but it's less commonly used.
*
* UPDATE: I've undone the above change, because when creating a disk image for an old application like:
*
* /apps/pcx86/1983/adventmath ["Adventures in Math" (1983)]
*
* it's important to create a disk image that will work with PC-DOS 1.0, which didn't understand 180Kb and 360Kb
* disk images.
*/
for (var iBPB = 3; iBPB < DiskDump.aDefaultBPBs.length; iBPB++) {
for (var iBPB = 0; iBPB < DiskDump.aDefaultBPBs.length; iBPB++) {
/*
* Use slice() to copy the default BPB, as a precaution (to avoid any changes to the default).
*/