7B ReadBlock¶

Stub MON 7B (7 decimal) · Mnemonic RPAGE · Group: File Operations (manual section 2.4)

Available from: not known - no compatibility box captured from the manual

Emulation source: src/handlers/mon_7B_ReadBlock.c

Description¶

Reads randomly from a file. You read one block at a time. The file must be opened for random read access.

The standard block size is 512 bytes. You can change this with SetBlockSize. The first block is number 0.

Parameters¶

Name	Type	Direction	Description
`FileNumber`	INTEGER2	In	File number. See OpenFile.
`BlockNo`	INTEGER2	In	Block number.
`DataDestination`	ARRAY	Out	Array for data returned.
`ErrCode`	INTEGER2	Out	Standard Error Code. See appendix A.

Direction: In = the program supplies the value, Out = the call returns it, In/Out = both.

Compatibility¶

ND-100	ND-500	User programs	RT programs	System programs
Yes	Yes	Yes	Yes	No

From the YAML extraction; this call's page in the manual had no compatibility box that was captured.

Examples¶

From the manual (OCR text, not corrected).

PLANCFORTRANPascalCOBOLMAC

INTEGER : FileNumber, BlockNo
BYTES : DataDestination(0:511)
...
ON ROUTINEERROR DO
    IF ErrCode > 0 THEN ...
ENDON
Monitor_Call('ReadBlock', FileNumber, BlockNo, DataDestination(0))

INTEGER FileNumber, BlockNo
INTEGER DataDestination(256)
...
Monitor Call('ReadBlock', FileNumber, BlockNo, DataDestination(1))
IF (ErrCode .NE. 0) THEN ...

FileNumber, BlockNo : INTEGER2;
DataDestination : ARRAY [0..15] OF RECORD...END;
...
ReadBlock(FileNumber, BlockNo, DataDestination);
IF ErrCode <> 0 THEN ...

01 FileNumber COMP.
01 BlockNo COMP.
01 DataDestination.
   02 array COMP OCCURS 256 TIMES.
01 ErrCode COMP.
...
MONITOR-CALL "ReadBlock" USING FileNumber, BlockNo, DataDestination.
CALL "CbError" USING ErrCode.
IF ErrCode NOT = 0 GO ...

LDT FILN0          %File number returned from earlier open.
LDA BLKN0          %Block number.
LDX (BUFF          %Address of buffer to receive block read.
MON 7              %Monitor call ReadBlock.
JMP ERROR          %Error return from monitor call.
...                %Normal return.
ERROR, ...         %Error number in register A.
...

FILN0, ...
BLKN0, ...
BUFF, 0
*+400/            %Make a buffer of 256 words.

ndmonlib implementation¶

Stub Registered MON_STATUS_NOT_IMPLEMENTED: the handler is a stub. mon_dispatch() in src/core/mon_dispatch.c reports the call as unimplemented without calling it.


Handler	`mon_7B_ReadBlock`
Code lines	7 (non-blank, non-comment lines in the file)

Source¶

SINTRAN III Monitor Calls (ND-860228.2 EN), page 394.