U UNIVAC 1218 - Bitsavers
U UNIVAC 1218 - Bitsavers
U UNIVAC 1218 - Bitsavers
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2.6.4 MAINTENANCE DATA TURNAROUND<br />
CHANGE 2<br />
The maintenance function provides a means for checking the linkage between<br />
the master and the slave. Performance of this function does not involve any<br />
slave peripheral device.<br />
When using the maintenance turnaround, full cycles must be used; that is,<br />
send data to slave and retrieve data from slave. Data will be returned to<br />
the master in the same code as sent to slave. The maintenance turnaround<br />
sequence is:<br />
1) Send a message header and output buffer containing turnaround data to<br />
the slaveg The MEFW should have a D field of O. The Message header<br />
has a function code of 5.<br />
2) Upon completion of output send a message header to the slave for input<br />
of turnaround data. The D field of the MEFW = 0 and the function code<br />
in the message header = 5.<br />
3) Send a MEFW for input to return data to the master.<br />
The output and input data transfer rules are found in Subsection 2.6.1 and<br />
2.6.2.<br />
2.7 ERROR NOTIFICATION<br />
Peripheral or format errors and interface errors can occur with the slave<br />
system. Subsection 2.4.2.2 describes the format errors. The sense byte of<br />
the EISW presents interface errors to the master. If the slave is unable<br />
to get the proper response from the ICCU, it comes to a stop and displays<br />
'F3'. This indicates that the slave attempted recovery and failed. The<br />
system should be cleared and restarted.<br />
3. 9200/9300 / ICCU INTERFACE<br />
3.1 INTRODUCTION<br />
To avoid duplication one basic interface will be used for the 9200/9300 Computer<br />
with the ICCU 18, 30, and 36-bit word lengths. The ratio between the<br />
number of characters per computer word and the length of the message header,<br />
creates a unique program for the 30-bit computer family. The only modification<br />
required between various data formats is in the number of bytes accepted in<br />
the header that is sent from the master computer.<br />
Since the 9200/9300 / ICCU interface is dependent upon the military computer/<br />
ICCU interface frequent reference will be made to Section 2.<br />
The basic interface between a 9200/9300 Computer and the ICCl] shall be defined<br />
as follows.<br />
II-G-17