User`s guide

BDOS FUNCTION 43: UNLOCK RECORD

Entry Parameters:

Registers C: 2BH

DE: FCB Address

Returned Value:

The Unlock 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

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

program can run at a time, this situation cannot occur. Thus, under CP/M 3, Func-

tion 43 performs no action except to return the value 00H in register A indicating

that the record unlock operation is successful.

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BDOS Function Calls CP/M 3 Programmers Guide