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NCB_POST@

Length: 4
Type:   DB
Description: NCB pointer to POST routine

Description
NCB_POST@ is a 4-byte field indicating the address of the routine that is to
be executed when the adapter has completed processing a command. This field
is used in no-wait options only. This field is in Define Double-Word format
(offset:segment) and must be a valid address in memory. Your POST routine
must establish DS and any other registers needed. Only AL, CS, ES, and BX
registers are set for the NCB being completed. The POST routine is called by
the adapter on interrupt level with interrupt masked. To return, issue an
IRET.
Your POST routine should be short and return immediately, unless you unmask
interrupts.

If the POST routine is specified as all zeros, a POST does not occur. This
allows a program to do other work and then loop until the NCB_CMD_CPLT field
changes from hex FF. When the change from hex FF occurs, either the command
executed or an error code was returned. Do net check the NCB_RETCODE because
it changes before the command is completed. This can be useful in a BASIC
program using PEEK and POKE.