IBM System/7 Functional Characteristics - All about the IBM 1130 ...

Printer Status AddressThis address contains the starting address of the status buffer (5 control words) thatis presented on every normal interrupt.Word CountThe word count is the number of words to be transferred during the operation. The outputprint line command requires the user to set a valid word count. The word count will be 0for a space or skip only operation. If the word count exceeds 66 the data transfer istruncated at 66. The incorrect record length bit is set in status word 1 and the 66 words thatwere transferred will print. The controller establishes the word count for all other printercommands.Data AddressThe data address is the address of the buffer in the System/7 to and from which data will betransferred. This parameter is fetched by the controller which holds it in a register, updatesit, and presents it to the 5024 during status transfer.Status BufferWhen the printer attachment presents an interrupt request as a result of an issuedcommand, 5 control words are placed in System/7 storage for program interrogation.0 15N Status word 1N+1 Status word 2N+2 Residual addressNot stored for an attention interruptN+3 Normal interrupt flagN+4 Attention interrupt flag} Not stored for a normal interruptIBM 5024 I/O Attachment Enclosure 17-23iii I I 1111111W,