User`s guide

BDOS FUNCTION 24: RETURN LOGIN VECTOR

Entry Parameters:

Returned Value:

Function 24 returns the login vector in register pair HL. The login vector is a 16-

bit value with the least significant bit of L corresponding to drive A, and the high-

order bit of H corresponding to the 16th drive, labelled P. A 0 bit indicates that the

drive is not on-line, while a 1 bit indicates the drive is active. A drive is made active

by either an explicit BDOS Select Disk call, number 14, or an implicit selection when

a BDOS file operation specifies a non-zero dr byte in the FCB. Function 24 maintains

compatibilty with earlier releases since registers A and L contain the same values

upon return.

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BDOS Function Calls CP/M 3 Programmers Guide