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

Sense Interrupt0 16 20 24 31Not used Device Fun Not used0 0 0 0 0 0 1 1I I I I I I I I■■•••,.,•••••■••■•••■•■••■•• •■••••■,...■••• •■••■,,..Mar. ••■••••••••••.'0 3 x ifAn )U0 instruction with a sense interrupt IOCC loads the 1130 accumulator with theinterrupt level status word (ILSW) associated with the highest priority level that is on, inorder to determine the interrupting device. The sense interrupt command is common toall 1130 I/O devices; therefore, no device-code field is needed.A System/7 interrupt request to the 1130 sets on ILSW bit 4 for interruption level 3.(The System/7 and the IBM 2250 Display Unit are mutually exclusive on the 1130 SAC.)Sense Device0 16 21 24 31Not used Device Fun Modifier0 1 1 010 1 1 1 0 0 0 oi000xIIIIIIIIIIIIIII iiii II milli••■••••,,.■ •■•■■■,..■•••• •■••••.,•■6 7 0 0 or 1An XIO instruction with a sense device IOCC loads the 1130 accumulator with the DSWfrom the 1130 host attachment in the System/7. The 1130 can determine the cause of aninterruption by analyzing these DSW bits.Modifier field bit 31 has the following meaning in this IOCC:Bit 31 = 0 — Do not reset DSW bitsBit 31 = 1 — Reset DSW bitsDSW bits can also be reset by turning on System/7 power or by the reset line in the1130 SAC.1130 Host Attachment 16-7