IBM 5280 Distributed Data System - Index of

Keyboard/Display External Register Write (KEYOP)Source: KEYOP (22, BRa, BRb)Object:JJC71 12 1 ~I I ~ 1 0 10 8 15 23 31I 7D D IID Keyboard operation number: The number that the main microprocessorstores in the keyboard/display lOB starting at hex displacement 1 F.fJ Register address: The address of the binary register that contains, in thelow-order byte, the external register to write.II From address: The address· of the binary register that contains the mainstorage address where the data to write into the external register iscontained.The contents of the main storage address are copied into the external registerspecified by the low-order byte of the binary register, as follows:01 = External register 502 = External register 1303 = External register 2504 = External register 26The operation should be issued only for diagnostic programming in a dedicatedmode. Following this operation, the keyboard/display microprocessor ignores allkeystrokes, the interval timer, parity errors, and the extended sense register untilan ENTR command or keyboard operation other than 1 F, 20, 21, or 22 is executed.When a diagnostic operation is issued, there is a change in external status 13 beforethe operation is executed. The contents of external register 13 depends on thekeyboard/display unit associated with the partition that issued the instruction, asfollows: for unit 1,40; for unit 2, CO; for unit 3, 44; for unit 4, C4. Register 25and bit 7 of register 26 should not be altered by the application program.See the notes under keyboard operation hex 1 F.Object Code Instruction Format 293