User`s guide

BDOS FUNCTION 42: LOCK RECORD

Entry Parameters:

Registers C: 2AH

DE: FCB Address

Returned Value:

The Lock Record function is an MP/M II function that is supported under CP/M 3

only to provide compatibility between CP/M 3 and MP/M. It is intended for use in

situations where more than one running program has Read-Write access to a com-

mon file. Because CP/M 3 is a single-user operating system in which only one pro-

gram can run at a time, this situation cannot occur. Thus, under CP/M 3, Function

42 performs no action except to return the value 00H in register A indicating that

the record lock operation is successful.

3-61

BDOS Function Calls CP/M 3 Programmers Guide