No fork() in MSC5.0, help...

Ralf.Brown at B.GP.CS.CMU.EDU Ralf.Brown at B.GP.CS.CMU.EDU
Sun Jul 24 21:04:42 AEST 1988


In article <1112 at nusdhub.UUCP>, rwhite at nusdhub.UUCP (Robert C. White Jr.) writes:
}I think you are missing one small point here.  "COMMAND.COM" is the 
}MS-DOS shell.  If you write something to replace it, you must
}*include* a loader of you own in the text of your shell.  If you
}look up the dos function call which loads programs, you will find
}that it invokes the shell (e.g. command.com) to do the loading.

That is only true of DOS 1.x and PC-DOS 2.x.  MS-DOS 2.x and MS/PC-DOS 3.x
have the loader in the kernel.  PC-DOS 2.x doesn't invoke COMMAND.COM,
it just happens that COMMAND.COM intercepts INT 21h and branches to a second 
transient portion containing the 1K or so of code to do the loading.
That's why PC-DOS 2.x requires COMMAND.COM to be present, as the loader code
may have to be read in from the COMMAND.COM file on disk.

--
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