Honeywell MTU9104 Operation Manual page 12

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the data transfer that is being set up. The number is
a positive binary quantity (bit 0 must be zero) and is
decremented by the MTC after each memory transfer.
A range of zero results in a subsequently issued
Read Forward order to perform the equivalent of a
Forward Space Block order transferring no data to
memory. A range of zero results in a subsequently
issued Write order setting the Operation Check bit
of Status Word 1, no data transfer, no tape motion
initiated, and termination of the order. Any address
and range register residue is applied to the next
command unless reset by another Output Range
instruction.
Command Output Configuration Word
Function Code 11
Format
Address Bus
7 8 1718 23
Request {
1
0
Cycle
rn°r.r.~~~~~~~~~IS
~~r+~~~~~~~
Not Used
I
Channel Number
I 0 I 0 0 0 II
. (Device). .
Data Bus
RFU·MBZ
Set Diagnostic Mode
Set
Low
Threshold
Inhibit ANSI Standard
' - - - - - 7·Track Even Parity Mode
' - - - - - Pack Mode (716 Word Mode)
' - - - - - RFU·MBZ
' - - - - - - RFU·MBZa
"Reserved for future use, must be zero.
Function
Loads the Configuration Word for the device cor-
responding to the referenced channel.
• Pack Mode - This bit set to one puts the NRZI
7 -track subsystem in Pack Mode. In this mode,
data transfers to and from memory start and'
end on byte boundaries and the range is
specified in bytes. However, ifthe range con-
tents specify an odd number of bytes, the
Operation Check bit in Status Word 1 is set, no
tape motion is initiated, and the read or write
order is terminated. For a write command, the
7 -track subsystem generates three characters
with odd
par~ty
on tape for each word obtained
from memory. The high-order twelve bits of
the word are written on tape as characters 1
and 2. The remaining four bits of the word are
recorded in the low-order locations of charac-
ter 3 with the remaining two bit locations
zero-filled. For a read command, a data word is
transferred to memory for each three charac-
ters read from tape or until the range register
has been depleted to zero.
Note:
The NRZI 9-track subsystem ignores
this bit.
PROGRAMMING
2-5
• 7-Track Even Parity Mode - This bit set to
one puts the NRZI 7 -track subsystem, ifnot in
Pack mode, into even (vertical) parity mode.
Even parity accompanies each data character
written on tape and VRC logic checks for
incorrect even parity during read and Read-
After-Write operations. Status Word 2 bit 5 is
set if errors are detected. This bit set to zero
puts the subsystem into the normal odd parity
mode.
Note:
The NRZI 9-track subsystem ignores
this bit.
• Inhibit ANSI Standard - This bit set to zero
requires that the ANSI Standard, write data
blocks of no fewer than 18 bytes from memory,
be adhered to; otherwise an Operation Check
occurs. Also, if during reading, 11 or fewer
characters from tape are detected, they are
interpreted as noise, Status Word 1 bit 4 is set,
and the search continues for the next block on
tape. This bit set to a one inhibits the ANSI
Standard and writing a minimum data block
of one or more characters is allowed. Also
allowed is the reading of one or more character
data blocks.
• Set Low Read Threshold - This bit set to one
allows the read threshold detection to be
reduced during read operations only.
• Set Diagnostic Mode - This bit set to one puts
the 7- or 9-track subsystems into the
Diagnostic mode. In this mode:
- Subsequently issued write orders generate
even vertical parity on 9-track tape (for use
in diagnosis; i.e., in the generation on tape
of data and check characters with bad
parity and blank characters and gaps of
specific lengths).
- Subsequently issued write orders to 9-
track devices generate incorrect CRC
characters on tape (for use in diagnosis).
- Subsequently issued non-forward motion
(Output Task Word) command transfers
data stored in the write FIFO adapter buf-
fer to the adapter DLI transmitter/receiver
logic and wraps the data around and into
the read FIFO adapter buffer.
This bit set to zero puts the NRZI tape adapter
subsystem attached to the MTC into its Normal
Mode (non-Diagnostic Mode).
Command
Output Interrupt Control
Function Code 03
CFIO