Quote:
Originally Posted by Freeshadow
Re DOS = brain-damaged: Seattle Computer Products QDOS, SCP's Quick and Dirty Operating System in 1980, later renamed to 86-DOS (predecessor of MS-DOS)
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Yep. Microsoft acquired it from SCP when IBM asked them for an OS for the IBM PC to go along with the version of BASIC they'd supplied. SCP based QDOS on a port of CP/M, to be the OS for a line of 8086 based machines using the S-100 bus.
IBM had previously spoken to Digital Research about getting a version of CP/M for the PC, and approached MS when that failed. (The apocryphal story back when was that DR President Gary Kildall preferred to fly his plane that day rather than meet with an IBM rep. The more likely story is that DR didn't like the terms IBM offered.) DR
did produce CP/M-86 later. (And, for that matter, CP/M-68K for Motorola architecture machines.)
Back in the early days, you could get MSDOS, CPM-86, or the UCSD P-System for the PC. (The P-system was used in other IBM products like the DisplayWriter dedicated word processor.) MSDOS won the OS wars on the PC.
But the heritage was why early MSDOS looked a lot like CP/M internally, and why there were quirks like ^Z as an End Of File marker. CP/M needed that because up until 3.0, CP/M didn't store the
size of a file in the directory entry, and the OS needed a marker to tell it where the file ended. I spent time back when configuring various apps to not use ^Z as EOF, and not treat it as one if encountered.
MSDOS took various notions from Unix, like tree-structured directories, pipes, and I/O redirection, but implemented them differently. I spent time back when trying to set my PC us to be as much like a Unix machine as possible. There were DOS versions of common Unix utilities around as shareware or freeware, but the solution proved to be a commercial offering called the MKS Toolkit. The Toolkit was a product of Canadian Mortice Kern Systems. The were consulting engineers who wrote it for their own internal use, and released it as a product when it reached a suitable point of development. It became the "tail that wagged the dog", and became their main business.
The Toolkit implemented every Unix command that made sense under a single-user, single tasking OS. The selling point for me was an implementation of the Unix Korn Shell that had everything except asynchronous background processes (because DOS didn't
do that.) Installed in fullest Unix compatibility mode, the Toolkit replaced COMMAND.COM with INIT.EXE as the boot shell in CONFIG.SYS. Init loaded and displayed a Login: prompt on the screen. Enter a userid, and INIT called LOGIN, which looked in a Unix style passwd file. If it found a match, it changed to what was specified as that ID's home directory, and ran whatever was specified as the ID's shell. Exit the shell, and INIT was reloaded and Login: displayed again.
I had ID's that ran the MKS Korn shell, vanilla COMMAND.COM, the shareware 4DOS COMMAND.COM replacement, and DesqView. I could switch environments without rebooting. When I was logged into the Korn shell, you had to dig to discover you
weren't on a Unix machine.
The Toolkit stayed in the loop when I moved to Win 3.1, since it ran on top of DOS. Win 3.1 used Program Manager as the default shell, but you could change that in the SYSTEM.INI file. I collected an assortment of alternatives, and created MKS IDs for them. Enter one at the Login: prompt, and a script copied an appropriately edited copy of SYSTEM.INI specifying the desired shell over the master and ran Windows with the chosen shell. Worked fine.
When Win9X came around I had to drop it, but it was fun while it lasted.
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Dennis