Speedup using INT 27H

[isrnix!jec]

There is one program that I know of that uses the INT 27H
and actually works (although it defines another interrupt for some
reason I can't figure out). Have you looked at SPEEDUP.COM? I think
it was originally published in PC Magazine in either issue 3 or 4.
I received another letter from someone else that had gotten
INT 27H to work for a screen printer (that spooled to the printer), but
he's had trouble with disk time-outs, but I suspect that was due
to the clock interrupt being foobared.
The code for SPEEDUP.COM is thus:

MOV DX,12H
MOV AX,251E
INT 21H ;CREATE INT 1E AT DS:12H
MOV DI,DX ;DI = 12H
MOV SI,DLOCH ;MOVE DATA INTO THE
MOV CX,0BH ; RESERVED PORTION OF
REPZ ; THE PROGRAM SEGMENT
MOVB ; PREFIX BLOCK.
XOR AX,AX
INT 13H ;RESET DISK
MOV DX,DI ;SET LOWMEM AT END
INT 27H ; OF THIS PROGRAM
DLOC: DB DF,02,25,02,08
DB 2A,FF,50,F6,00
DB 04

This is a nifty little program even aside from showing how to
use INT 27H. If you have DOS 1.0 this will speed up your disk access
time by almost 100%. All you have to do is run it.

Now, anyone out there with a working spooler?

Mike (...devax!pur-ee!iuvax!isrnix!jec)