22B OutUpTo8Bytes¶

In progress MON 22B (18 decimal) · Mnemonic M8OUT · Group: File Operations (manual section 2.4)

Available from: All programs (manual compatibility box)

Emulation source: src/handlers/mon_22B_OutUpTo8Bytes.c

Description¶

Writes up to 8 characters to a device, e.g. a terminal or an internal device.

Notes¶

You can only use this monitor call for terminals, TADs, internal devices, and synchronous modems.
The writing terminates when a character with value 0 is found. The 0 byte is not output.
Appendix F contains an ASCII table.
Standard Error Code is returned via ErrCode variable in high-level languages, or in W1 register for ASSEMBLY-500. The K flag indicates if an error occurred.

Parameters¶

Name	Type	Direction	Description
`DeviceNo`	INTEGER	In	Logical device number. Use 1 for your own terminal. File numbers are illegal.
`OutData`	STRING	In	The 8 characters to be written (writing stops at first 0 byte).

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

Compatibility¶

Machines	Users	Programs
ND-100 and ND-500	All users	All programs

The manual's compatibility box for this call, word for word.

Yes/no fields from the YAML extraction (not in the manual's words):

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

Examples¶

From the manual (OCR text, not corrected).

PLANCFORTRANPascalCOBOLASSEMBLY-500MAC

    INTEGER : DeviceNo
    BYTES : OutData(0:7)
    ...
    ON ROUTINEERROR DO
    IF ErrCode > 0 THEN ...
    ENDON
    Monitor_Call('OutUpTo8Bytes', DeviceNo, OutData)

INTEGER DeviceNo
CHARACTER OutData*8
...
Monitor_Call('OutUpTo8Bytes', DeviceNo, OutData(1:8))
IF (ErrCode .NE. 0) THEN ...

DeviceNo : INTEGER2;
OutData : RECORD...END;
...
OutUpTo8Bytes(DeviceNo, OutData);
IF ErrCode <> 0 THEN ...

01 DeviceNo COMP.
01 OutData PIC X(8).
01 ErrCode COMP.
...
MONITOR-CALL "OutUpTo8Bytes" USING DeviceNo, OutData.
CALL "CbError" USING ErrCode.
IF ErrCode NOT = 0 GO ...

    DeviceNo : W BLOCK 1
    OutData : STRINGDATA 8
    ErrCode : W BLOCK 1
    OutUpTo8Bytes : EQU 37B9 + 22B
    ...
    CALLG OutUpTo8Bytes, 2, DeviceNo, OutData
    IF K GO ERROR
    ...
    ERROR : W1 =: ErrCode               %ErrorCode in W1 register.

    LDT  DEVNO           %Logical device address.
    LDD  BYTES           %First 4 bytes to be written.
    LDX  BYTES+2         %Next 2 bytes to be written.
    COPY SX DL
    LDX  BYTES+3         %Last 2 bytes to be written.
    MON  22              %Monitor call OutUpTo8Bytes.
    JMP  ERROR           %Error return from monitor call.
    ...
                          %Normal return.
    ERROR, ...           %Error number in register A.
    ...
    DEVNO, ...
    BYTES, 'HELLO!!!'

ndmonlib implementation¶

In progress Registered MON_STATUS_IN_PROGRESS: partly implemented. The dispatcher calls the handler.


Handler	`mon_22B_OutUpTo8Bytes`
Code lines	48 (non-blank, non-comment lines in the file)

Emulation research¶

Source

This section comes from the emulation: block of the call's YAML file in the NDInsight repo. It records what was learned while implementing the call in nd500x; its status is nd500x's, not ndmonlib's.


Status (nd500x)	implemented
nd500x handler	nd500x/src/libmon/handlers/mon_22B_OutUpTo8Bytes.c
Last updated	2026-07-17

Parameter notes¶

1. OutData

Field	Value
Note	Taken as a RAW BYTE ADDRESS (arg_addresses[1]) and read byte by byte - NOT as an ND-500 [Length][Pointer] descriptor and NOT as a 0x27-terminated SINTRAN string. Contrast 32B OutMessage (descriptor) and 162B OutString (descriptor in its 2-arg form). If a caller passes a descriptor here it will print the descriptor bytes.
Verified	Yes

2. DeviceNo

Field	Value
Note	32-bit word. File numbers are rejected before anything is written.
Verified	Yes

Return contract¶

Success: K flag cleared; 0 to 8 bytes written.

Errors

Code	Octal	Meaning
124	174B	Illegal parameter (a file number was passed - the manual says file numbers are illegal)
24	030B	No such device name (not a character device or terminal)
111	157B	Missing parameter (fewer than 2 CALLG args)

Verified¶

1. Writing stops at the first 0 byte and the 0 is NOT output; at most 8 bytes are written.

Field	Value
Evidence	Implements the manual's own rule ("Writing terminates when a character with value 0 is found. The 0 byte is not output.") - mon_22B_OutUpTo8Bytes.c loop over i < 8 with break on b == 0.

2. File numbers are rejected, per the manual's "Only for terminals, TADs, internal devices, and synchronous modems. File numbers are illegal."

Field	Value
Evidence	is_mass_storage_file(device_no) -> error 124 (174B), before any output.

Unverified¶

NO OBSERVED CALLER. No traced program (NC, CAT-500, ND linker) issues 22B; they use 504B DVOUTS / 162B OUTST. Implemented but NOT proven end to end.
Error 124 (174B Illegal parameter) for the file-number case is a CHOICE, not a read value - the manual says file numbers are illegal but does not give the code it returns.
TADs, internal devices and synchronous modems (the other device classes the manual permits) are not modelled at all; nd500x accepts only character devices and terminals and returns 24 (030B) for everything else.

Sources¶

Doc	Note
SINTRAN III Monitor Calls (ND-860228.2 EN)	The manual body of this YAML.

Source¶

SINTRAN III Monitor Calls (ND-860228.2 EN), page 387.