Problems With Interrupts; Other Compatibility Issues - Husky MP2500 Manual

port. These will not work on MP2500. Such applications are rare, and you
may be able to obtain an unprotected version on special request.
The MP2500 hardware is to a large extent IBM PC-compatible, so you can
even use many 'badly behaved' applications too, such as most TSR
packages.
Note: If you are in any doubt about the suitability of a particular package,
contact your supplier or H
(see section 17.4).

17.1.1 Problems with interrupts

NMIs: On IBM PCs, NMIs are either used to report a RAM parity error or not
used at all. The MP2500 uses NMIs for several other purposes. While this
is generally not a problem, it can affect the use of certain packages,
described here.
If an application redirects the NMI vector, this will crash or hang the
MP2500. Programs that do this include CODEVIEW, TURBO BASIC (or
POWER BASIC) and some C++ compilers. To use such a program, you
must patch the code to either prevent redirection or cascade the
application's NMI handler from the MP2500 one. An application's NMI
handler is normally used as a "catch all" error handler, eg to catch numeric
co-processor errors, on a PC-AT system. Contact your system supplier or
H if you experience difficulties.
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Maskable interrupts: Finally, applications which rely on the use of the CLI
instruction to mask (disable) all interrupts other than NMI may also cause
problems, since NMIs are issued regularly on the MP2500, unlike the PC
(where it indicates a memory error and halts the system).

17.1.2 Other compatibility issues

MP2500 is more PC-compatible than some earlier H
as the H FS/2. For example, it uses a PC-compatible 16450 UART,
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Timer, Interrupt Controller and HDC devices; the processor does not have
any reserved flags; the disk architecture is entirely PC-compatible and the
BIOS entry points are also standard.
166
, or arrange to test the application
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H MP2500 System Developer's Guide
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computers such
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