Running PC-Doctor DOS from USB drive: Solution
Posted: Mon May 28, 2012 5:34 am
So, to prepare for a upcoming troubleshooting session with my friend's X60, and for the general welfare of my own X60t, I want to boot the PC-Doctor DOS CD (1ety48ww, for T3x/T4x/T6x/R4x/R5x/R6x/X3x/X4x/X6x/A3x/G4x/G5x/Z6x) from a USB drive.
Attempt 1: Load the ISO via SYSLINUX and MEMDISK. The image will boot, but hangs randomly when extracting files to RAM.
Attempt 2: Load the ISO via GRUB4DOS. The image will not boot.
Attempt 3: Since the CD boots via harddisk emulation, I extracted the hard disk image file from the ISO (1ety48ww.ima). Although WinImage reads the contents of this image fine, it does not boot via GRUB4DOS either; GRUB4DOS complains about being unable to mount the drive.
Then, I opened the hard disk image with a hex editor. The first couple hundreds of bytes contains references to "Roxio CD/DVD-ROM Boot Loader v1.01". Some blank bytes follow, and at offset 0x00004000, strings like "IBM 7.1" and "FAT16" appeared.
Solution: Using a hex editor, open up the hard disk image 1ety48ww.ima, and delete everything between the start of the file and offset 0x00004000. The image should start with:
Then, boot this modified image (now a partition image instead of disk image) via GRUB4DOS. The relevant entry in my menu.lst reads:
Notice the use of (hd0,0) instead of (hd0), since the image is only one partition, not an entire disk. Voila! It boots and runs perfectly.
Hope this helps someone.
Attempt 1: Load the ISO via SYSLINUX and MEMDISK. The image will boot, but hangs randomly when extracting files to RAM.
Attempt 2: Load the ISO via GRUB4DOS. The image will not boot.
Attempt 3: Since the CD boots via harddisk emulation, I extracted the hard disk image file from the ISO (1ety48ww.ima). Although WinImage reads the contents of this image fine, it does not boot via GRUB4DOS either; GRUB4DOS complains about being unable to mount the drive.
Then, I opened the hard disk image with a hex editor. The first couple hundreds of bytes contains references to "Roxio CD/DVD-ROM Boot Loader v1.01". Some blank bytes follow, and at offset 0x00004000, strings like "IBM 7.1" and "FAT16" appeared.
Solution: Using a hex editor, open up the hard disk image 1ety48ww.ima, and delete everything between the start of the file and offset 0x00004000. The image should start with:
Code: Select all
Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
00000000 EB 58 90 49 42 4D 20 20 37 2E 31 00 02 04 01 00 ëX.IBM 7.1.....
00000010 02 00 02 00 00 F8 85 00 20 00 40 00 20 00 00 00 .....ø…. .@. ...
00000020 4F 13 02 00 80 00 29 F5 12 4E 0A 44 52 49 56 45 O...€.)õ.N.DRIVE
00000030 2D 43 20 20 20 20 46 41 54 31 36 20 20 20 90 90 -C FAT16 ..
00000040 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 ................
Code: Select all
title PC-Doctor for ThinkPad T3x/T4x/T6x/R4x/R5x/R6x/X3x/X4x/X6x/A3x/G4x/G5x/Z6x
map --mem /pcdoctor/short.ima (hd0,0)
map --hook
root (hd0,0)
chainloader +1Hope this helps someone.