Texas Instruments 990 Operation Manual page 101

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945255-9701
Errors: An unrecoverable I/O error is returned if:
• An I/O error occurs.
• The output cassette is not ready.
3.5.2.4 Write End of File. The Write End of File supervisor call writes an end-of-file record to a
tape cassette.
Supervisor call code: 0
I/O operation code: D
Calling parameter:
luno Logical unit number of the drive on which the tape cassette is mounted.
Result: This supervisor call causes an end-of-fJ.le record to be written to the specified cassette.
This call is ignored by other devices.
Error: An unrecoverable I/O error is returned if an I/O error occurs or if the output cassette is
not ready.
3.5.3 NON-I/O SUPERVISOR CALLS. The data block for a non-I/O supervisor call is a
parameter block containing two to eight bytes. It has the following format:
The parameters are:
op
error code
sign
value
1ST BYTE
2ND BYTE
<op>
o:s
<error code>
00
o
2
<s~n~OR
PART
-<value~!,>
ZO
~-'
... ,'j
4
,to
<value>
S-'
r
6
3,J
Operation code
Code which is set to one if an error is
encountered
Algebraic sign associated with
it
parameter
value - plus
(+),
minus (-), ASCII zero
or blank
Parameter value
3-63
I ....
,-
-
,.
USED FOR
DATA CONVERSION
ONLY
Digital Systems Division