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

Set Diagnostic ModeO 5 8 11 16 20 26 31Op code R Fun Zeros Mod DA MA00001 XXX 001000000010100000 XX XXXX1111 II II 1111 III 11111 11111O8-F 2 0 2 8 0-3 XThis command places the 2790 Control function in one of four states, depending upon thevalue of bits 14 and 15 in the index register (R), or the accumulator if R=000.The four possible states set by this command are:Bits State14 150 1 Diagnostic mode. The 2790 Control is set in diagnosticmode of operation for use with the set-input-buffercommand described later. ISW bit 5 is also set on toindicate that the diagnostic mode is effective. While inthe diagnostic mode, the 2790 Control constantly checksfor the presence of sync characters in bytes 5 to 29 of aframe cycle. Any missing sync bytes are indicated by settingon bit 6 in the ISW.110010Loop bypass. The 2790 loop is bypassed. Output from theoutput buffer register is connected directly to the input ofthe input buffer register.Diagnostic and loop bypass. Output frames from the 2790Control enter directly into the input buffer register and arechecked for sync characters in bytes 5 to 29.Normal operation. This code resets the above three states andremoves the 2790 Control from the diagnostic and/or bypassmodes of operation.Set Input Buffer ControlO 5 8 11 16 20 26 31Op code R Fun Zeros Mod DA MA00001 X XX 0 01000000011100000 XXXXXX1111 11 II 1111 111 11111 11111•••■••■■••–ov–• ••■•■O 8-F 2 0 3 8 0-3 XThis command loads a sync character (hexadecimal 47) or a character containing all l'sinto the input buffer register, depending on the setting of bit 15 in the index register (R),or the accumulator if R=000. A set-diagnostic-mode command must set the 2790 Controlfunction in diagnostic mode before executing a set-input-buffer-control command.IBM 5012 Multifunction Module Model Al 13-43