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67 lines
2.6 KiB
Plaintext
67 lines
2.6 KiB
Plaintext
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Multi-Taking MS-DOS
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Beta Test Release 1.00
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Release Notes
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Enclosed you will find Microsoft's first beta release
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of Multi-tasking MS-DOS. This version is based upon MS-DOS
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Version 2 sources, we will be reimplementing the multi-
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tasking enhancements on top of Version 3 sources shortly.
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Although we have distributed a bootable disk for the
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IBM PC, this package can be adapted to any MS-DOS machine.
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Those manufacturers who are designing IBM compatible ROMs,
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would be wise to keep multi-tasking in mind. Specifically,
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this IBM PC implementation has had to hook out the entire
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disk (both floppy and hard disk) ROM code because after he
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IBM code set's up the DMA transfer it simply loops in ROM
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waiting for the interrupt to occur (routine WAIT_INT).
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Problems you may wish to avoid within future ROMs are:
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1) loading ES with the physical video RAM location
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(label M3)
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2) Looping in ROM on Cntrl-NumLock (label K40)
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3) No way to add special detecting special key
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strokes which a jump out into RAM after reading
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the keystroke at KB_INT would avoid
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4) Not being able to hook the loading of DS to point
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to DATA (EQU 40H) in numerous routines.
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Other than these deficiencies the ROM code developed should
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be very usable.
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By implementing the above suggestions, the size of your
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BIOS can be reduced since it will not be necessary to
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duplicate functionality in RAM.
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More detailed specifications of the device driver
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formats will be forth coming. For the time being you will
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have to make use of the sample source code for the IBM PC.
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If you have further questions please contact Microsoft OEM
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customer support through Technical Assist Requests (TAR).
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* * * WARNING * * * WARNING * * * WARNING * * *
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Each copy of this software distribution has been
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individually serialized to facilitate tracing of
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unauthorized duplication.
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* * * WARNING * * * WARNING * * * WARNING * * *
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