Category : Alternate Operating Systems - Quarterdeck DesqView, CP/M, etc
Archive   : DVDEVL12.ZIP
Filename : DVEOP.API

DVeop (c) Copyright 1991 Ralf Brown

DVeop is a support program for DVdevload and any other XDI drivers run inside
DESQview windows which require notification on process termination.

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DVeop API:
XDI function 01h (driver custom function) on INT 2Fh
Call with: AH = XDI multiplex number (usually DEh)
AL = 01h
BX = 5242h ("RB", indicates a program by Ralf Brown)
CX = 656Fh ("eo") \
DX = 7000h ("p",0) / identifies DVeop
Returns: AX = 5242h ("RB") if installed
ES:BX -> DVeop entry point
CX = version (CH = major, CL = minor)

DVeop entry point
Call with: ES:DI -> FAR function to be called when window closes
or 0000h:0000h to remove callback
Return: AX = status
0000h failed (callback table full or attempted to
remove nonexistent callback)
0001h successful
ES:DI -> previous callback function
BX,CX,DX destroyed
Note: If the previous callback function is not 0000h:0000h,
the new callback function must chain to the previous
function.

The callback function is called with a simulated interrupt call
with BX and DX as on entry to XDI function 05h (process
termination), and must preserve all registers. It should perform
a far jump to the previous callback function after performing its
processing, or an IRET if the previous callback address is
0000h:0000h.