PC-DOS 7.1, not to be confused with PC-DOS 7.0 revision 1 (aka PC-DOS 2000), was a series of updates to PC-DOS 2K, most prominently featuring support for logical block addressing (LBA) and FAT32. It was not made available commercially, and is not a complete OS. Installing it under VirtualBox proved tricky for me (I'll detail my experience in a subsequent post). In the end, I had to install PC-DOS 7.0, then replace it with the 7.1 files.
I. Build the installation disk
As a result of a number of issues I encountered I was unable to install PC-DOS 7.1 directly onto a hard drive under VirtualBox 5.18. Instead, we're going to do it in a round-about way via PC-DOS 2000.
- Get yourself a bootable PC-DOS 2000 floppy disk image (you're on your own here, but it shouldn't be too difficult -- nudge nudge wink wink). Pare it down to only the following six files:
ATTRIB.EXE COMMAND.COM IBMBIO.COM IBMDOS.COM FDISK.COM FORMAT.COM
- Download a copy of the IBM ServerGuide Scripting Toolkit, DOS Edition (SGTK): https://www-947.ibm.com/support/entry/p ... MIGR-53564. Unpack the SGTK package and locate the PC-DOS 7.1 files in sgdeploy/sgtk/DOS/.
- Make a subdirectory on your installation floppy (I called mine PCDOS71) and copy all the PC-DOS 7.1 files from the SGTK into it. Don't forget the AUTOEXEC.BAT and CONFIG.SYS file in sgdeploy/sgtk/DOS/cfgfiles/.
Create a basic DOS VM in VirtualBox. Just take all the default settings.
III. Install PC-DOS 2000
- Boot your DOS VM from the installation image you created in Step I.
- When you get to the A:\> prompt, run FDISK and create a primary DOS partition on your hard drive -- just press ENTER four times to take all the defaults and reboot the VM.
- Now format the C: drive, give it a label and transfer the system files:
A:\>format c: /v:pcdos71 /s WARNING: ALL DATA ON NON-REMOVABLE DISK DRIVE C: WILL BE LOST! Proceed with Format (Y/N)?Y Formatting 499.53M System transferred 523,526,144 bytes total disk space 139,264 bytes used by system 523,386,880 bytes available on disk 8,192 bytes in each allocation unit. 63,890 allocation units available on disk. Volume Serial Number is 1E48-1107
In addition to formatting the partition, the above FORMAT command also writes a DOS boot record to the C: partition and transfers the three system files, IBMBIO.COM, IBMDOS.COM and COMMAND.COM You can check:
A:\>DIR C:\ /aa Volume in drive C is PCDOS71 Volume Serial Number is 1E48-1107 Directory of C:\ IBMBIO COM 40,726 04-30-98 1:00p IBMDOS COM 37,066 04-30-98 1:00p COMMAND COM 52,965 04-30-98 1:00p 3 files(s) 130,757 bytes 523,386,880 bytes free
We really only wanted the boot record from PC-DOS 2000, so now we'll replace the system files with 7.1's.
- Delete the 7.0 system files:
A:\>ATTRIB -S -H -R C: A:\>DEL C:\*.* All files in directory will be deleted! Are you sure (Y/N)?Y
- Copy the 7.1 system files to the C: drive. Make sure you do it in this order!
A:\>CD PCDOS71 A:\PCDOS71>COPY IBMBIO.COM C: 1 file(s) copied A:\PCDOS71>COPY IBMDOS.COM C: 1 file(s) copied A:\PCDOS71>COPY COMMAND.COM C: 1 file(s) copied A:\PCDOS71>COPY CONFIG.SYS C: 1 file(s) copied A:\PCDOS71>COPY AUTOEXEC.BAT C: 1 file(s) copied
- Create a DOS directory on C: and copy the 7.1 files into it:
A:\PCDOS71>MKDIR C:\DOS A:\PCDOS71>COPY *.* C:\DOS ... XCOPY.EXE 43 file(s) copied
We're done! Your C:\ drive should now look like this:
A:\PCDOS71>DIR C:\ Volume in drive C is PCDOS71 Volume Serial Number is 1E48-1107 Directory of C:\ IBMBIO COM 44,656 06-29-05 6:03a IBMDOS COM 42,566 06-29-05 6:03a COMMAND COM 53,802 06-29-05 6:02a CONFIG SYS 135 06-16-06 12:45p AUTOEXEC BAT 753 03-31-05 4:09a DOS <DIR> 11-07-16 12:13p 6 file(s) 141,912 bytes 522,354,688 bytes free
V. Boot
Unmount the floppy image, and reboot the VM. You should wind up at a C:\ prompt. Type VER to check.
Starting PC DOS... HIMEM:DOS XMS Driver, Version 3.15 - 05/30/94 Extended Memory Specification (XMS) Version 3.0 Copyright (C) IBM Corp. 1988, 1994 128 extended memory handles available. Installed A20 handler number 2. 64K High Memory Area is available. C:\>ver PC DOS Version 7.1 Revision 0
Wrap-Up
- This issues I encountered prevented me from creating a FAT32 partition.
- The PC-DOS 7.1 files in the IBM ServerGuide Scripting Toolkit do not represent a full OS. Many of the standard utilities are missing. If you have a copy of PC-DOS 2000, you can simply copy files from there. Just be sure not to overwrite any files with the same name.
- And if anyone has figured out how to install 7.1 directly, let me know how you did it.