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Work-around to detect 615-cylinder hard disks

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This commit is contained in:
Jeff Parsons 2015-12-18 14:34:56 -08:00
commit e5a4a050b4
2 changed files with 17 additions and 9 deletions
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20
modules/diskdump/lib/diskdump.js
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@ -2142,14 +2142,18 @@ DiskDump.prototype.convertToJSON = function()
var cbDiskData = this.bufDisk.length;
if (cbDiskData >= 3000000) { // arbitrary threshold between diskette image sizes and hard disk image sizes
/*
* In this case, the first sector should be an MBR; find the active partition entry,
* then read the LBA of the first partition sector to calculate the boot sector offset.
*/
for (var offEntry = 0x1BE; offEntry <= 0x1EE; offEntry += 0x10) {
if (this.bufDisk.readUInt8(offEntry) >= 0x80) {
offBootSector = this.bufDisk.readUInt16LE(offEntry + 0x08) * cbSector;
break;
var wSig = this.bufDisk.readUInt16LE(0x1FE);
if (wSig == 0xAA55) {
/*
* In this case, the first sector should be an MBR; find the active partition entry,
* then read the LBA of the first partition sector to calculate the boot sector offset.
*/
for (var offEntry = 0x1BE; offEntry <= 0x1EE; offEntry += 0x10) {
if (this.bufDisk.readUInt8(offEntry) >= 0x80) {
offBootSector = this.bufDisk.readUInt32LE(offEntry + 0x08) * cbSector;
cbDiskData = this.bufDisk.readUInt32LE(offEntry + 0x0C) * cbSector;
break;
}
}
}
/*