System information

FUNCTION21: WRITE SEQUENTIAL

Entry Parameters:

Registers DE: FCB Address

Returned Value:

Given that the FCB addressed by DE has been activated through an Open or Make function, the

Write Sequential function writes the 128-byte data record at the current DMA address to the file

named by the FCB. The record is placed at position cr of the file, and the cr field is automatically

incremented to the next record position. If the cr field overflows, the next logical extent is

automatically opened and the cr field is reset to zero in preparation for the next write operation.

Write operations can take place into an existing file, in which case newly written records overlay

those that already exist in the file. Register A = 00H upon return from a successful write

operation, while a nonzero value indicates an unsuccessful write caused by a full disk.

5.2 Call Conventions CP/M Operating System Manual

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