Compatibility: 1.0+
Expects: AH    26H
DX    segment address (paragraph) for new PSP
CS    segment of a PSP to use as a template for the new PSP
Returns: none
Info: Sets up a PSP for a child process at DX:0000.

  the current PSP (100H bytes starting at CS:0) is copied to DX:0

  the MemTop field is adjusted

  Terminate, Ctrl-Break, and Critical Error vectors are copied
into the PSP from the vectors for INT 22H, INT 23H and INT 24H.

You may then load a program from disk and run it with a FAR JMP.
See EXE Header for information on manually loading an EXE-format
file.  See Program Startup & Exit for related information.

Notes:   Avoid this call; use DOS Fn 4b00H (exec) or 4b01H (load
overlay) instead.

  If you intercept INT 21H be sure to leave the correct CS:IP on
the stack.

- -

DOS Fn 26H: Create Program Segment Prefix