Tim wrote:
> The CPM API was mainly done through software
> interupts with register variables setup to do whatever function you wanted.
> Paterson duplicated the API functions added some of his own and mimicked the
> described behaviour. He wanted programmers to be able to port their software
> very easily from CPM.
it was duplicated to the level that the first 100 (hex) bytes ( all
programs under cp/m started execution at 0100H) contained the
appropriate cp/m BDOS subroutine call at location 0005H in addition
to the recommended DOS software interrupt, & most of the 'BDOS primate
functions', (print character, get key input, print string, etc.) carry
the same 'a' register 'selector' values.
DavidT
Adelaide
South Australia
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