- File present, word 0 bit 1
- This bit is set is the file code is present and does not represent
a released file.
This bit should be checked before examining other fields.
- file type, word 0 bits 30-35
- One of the following octal codes will be stored in this field.
These are almost the same codes used by MME GEFCON,
except for minor variations in two sysout codes.
- 02
- magnetic tape
- 04
- obsolete, was 40-word sector drum
- 05
- remote sysout ($REMOTE)
- 06
- 64-word sector disc.
- 07
- conversational device ($DAC)
- 10
- card reader
- 12
- printer
- 13
- console (default or $TYPE)
- 14
- obsolete, was paper tape
- 16
- card punch
- 20
- central or remote sysout.
(default or $SYSOUT)
- device address: word 2
- This contains the same device address information as
MME GEFADD returns in the Q register.
PMME FILINF also returns a copy of this word in the Q register.
- Sysout files
- Although a program does nothing different for central site
sysout and remote sysout, both MME GEFADD and PMME FILINF
try to distinguish in the information they return to the caller.
They do not exactly agree on how the difference is determined.
In addition to the type codes (05 and 20), PMME FILINF
sets two bits in word 0 depending on what type of sysout.
A program will normally get test both bits, and treat the file
as sysout if either is set.
- plain sysout, word 0 bit 1
- The file is a sysout file defined by a $SYSOUT card,
or implicitly by the system.
If this is set, the type code will be octal 20.
This may be central or remote sysout depending on the $SYSOUT card.
- $REMOTE, word 0 bit 2
- The file is remote sysout defined by a $REMOTE card.
If this is set the type code will be octal 05.
A $SYSOUT card that specifies remote sysout,
will NOT cause this bit to be set.
- Conversational devices
- Note that a $DAC control card does not actually connect a terminal to
the program.
It is up to the program to recognize from that a $DAC card was
used and issue the appropriate GEROUT or remote CALLIO calls.
- Unit designator, word 0 bits 24-29
- A single BCD character taken from the second field of the $DAC card;
if there is no explicit second field a blank is returned.
By convention, this character is appended to the snumb of job to
generate the remote inquiry name used for this file.
- Printers
- Some information about the printer capabilities is returned.
This information is a subset of that returned by MME GEFADD
and PMME PHFADD which should probably be used instead.
- ASCII capable, word 0 bit 12
- This bit will be set if this type of printer can accept ASCII data.
- 136 capable, word 0 bit 16
- This bit will be set if the printer can handle at least 136 columns.
If it is not set, no more than 132 columns can be assumed.
- Card Readers and Punches
- Again, the capability information is a subset of that returned
by MME GEFADD.
- Word 0 bits 12-13
- These bits will be set to 11 is the device has ASCII capability,
and to 00 if it does not.
- Disk files
- Mode, word 0 bit 4
- This bit will be 0 for sequential files,
and 1 for random ones.
- File size, word 1
- The file size in llinks is stored in this word.
- Magnetic Tapes
- For tape, the file information block must have at least 3 words,
but may be larger.
If at least 6 words are supplied, filename and generation data
is returned,
and if 8 words are supplied primary and alternate device names
are returned.
- Non-7 track indicator, word 0 bit 3
- This bit will be set to zero in the unlikely event that a
7 track tape drive is assigned to the file.
Normally it will be a 1, indicating some other tape type
(9 track or cartridge).
- Dismount code, word 0 bit 20
- This is the lower bit of the 2 bit normal disposition code.
Please see "expl mme gefcon" for a discussion of its meaning,
and utility (non-utility?).
- Starting Reel Index, word 0 bits 21-29
- See discussion in "expl mme gefcon" for the meaning of this field.
- File Serial Number, word 1 bits 0-29
- The BCD file serial number from the PAT is stored here.
If the PAT is marked as not having a reel number,
then `99999` will be stored.
- FIPS file version number, word 3 bits 0-17
- If the $TAPE card specified a FIPS generation and version number
(GnnnVnn field), then the version number is stored here.
- FIPS file generation number, word 3 bits 18-35
- If the $TAPE card specified a FIPS generation and version number
(GnnnVnn field), then the generation number is stored here.
This information is not available through MME GEFCON.
- Tape file name, words 4 and 5
- The 12 character BCD file name from the $TAPE card will be stored here.
This information is not available through MME GEFCON.
- Primary device name, word 6 bits 0-17
- The 3 BCD character device name of the primary tape drive is returned here.
- Secondary device name, word 6 bits 18-36
- If a secondary tape drive is assigned, its device name will be returned here.
If no secondary drive is assigned,
then BCD spaces will be stored.
- RFU, word 7
- No information is returned in this word,
but space for it must be supplied if the device name data
is required.
Update PAT tape number
This function is requested by setting code 100,
"request type" field of the Q (bits 0-2).
If specified, the BCD file serial number is copied from
bits 0-29 of word 1 in the data block to the PAT.
Please see "expl mme gefcon" for further discussion of
this function.
Update PAT density
This function is specified by setting code 010 in the
"request type" field of the Q.
If specified, bits 14-17 of the Q will be copied to
the PAT density field.
Please see "expl mme gefcon" for the effects of changing
the PAT density field,
and "expl mme gefadd" for the density code values.
Update tape block count
This function is specified by setting code 001 in the
"request type" field of the Q.
If specified, the value in word 1 bits 0-17 will be stored into
the "blocks from prior EOF" field in the GCOS tables that
keep track of the tape position.
There is no corresponding functionality in MME GEFCON,
and it is not clear why a user program would ever need to do
this since the system keeps track of this information.
If the wrong value was specified,
and a later a reposition tape optation was performed because of a
drive exchange or error recovery, then data could be lost.
See Also:
- expl mme gefadd
- for the format of the physical device address data,
tape density codes,
and more complete unit record capability and state data.
- expl mme gefcon
- for further discussion of the update functions,
and more explanation of the interpretation of some of
returned data.
Copyright © 2000, Thinkage Ltd.