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

Error RecoveryIf the output diagnostic/initialize controller command is unsuccessful and the 5024 ison-line to the System/7, a reset 5024 command must be issued and the initialization retried.If retry fails, verify the IOTBs and data tables and retry the operation.IBM 2502 CARD READERThe 2502 Card Reader accepts input from standard 80 column punched cards, with amaximum throughput of 300 cards per minute. The data controller transfers this inputby cycle stealing when the input has been read from one card. The operator can initialprogram load (IPL) the System/7 from the 2502, except with SBCA (Sensor Based ControlAdapter, RPQ D08119).Initiate I/OCycle steal occurs when an initiate I/O is directed to the 2502. This fetches the IOTB whichcontains the control parameters. If the module address (MA) is not zero a program checkoccurs. Initiate I/O format is:150 0 0 0,0 0 0 0,0 0 0 0 1 0 0 01 1 1 I 1 1 1 I 1 1 1 1 1 10 0 0 1Contents of registerspecified in reg fieldInitial Program Load (IPL)The 2502 Reader will support operator initiated IPL (except with SBCA) but not autorestartIPL. Card format is punched card code (Hollerith). Each four card columnswill be translated to Hex digits (0-F) and stored in processor storage as a word,starting in location 0000. The first four columns of card 1 will be stored as thefirst word, in storage location 0000. A total of 1224 columns (17 cards) of punchedinformation is required to IPL 306 words in storage. Cards are read sequentially untilall 1224 columns have been read. Columns 73-80 are reserved for ID and/or sequencenumbers. These columns are not included in the required 1224 data columns and will notbe transmitted to storage.Characters 0-9 and A-F are translated to their corresponding hex code. A blank cardcolumn will translate to a hex 0. Non-valid punches will cause a validity check.IBM 5024 I/O Attachment Enclosure 17-9