Shown below are the known CIO STATUS BYTE values.
01 (001) -- OPERATION COMPLETE (NO ERRORS) 80 (128) -- [BREAK] KEY ABORT 81 (129) -- IOCB ALREADY IN USE (OPEN) 82 (130) -- NON-EXISTENT DEVICE S3 (131) -- OPENED FOR WRITE ONLY 84 (132) -- INVALID COMMAND 85 (133) -- DEVICE OR FILE NOT OPEN Sb (134) -- INVALID IOCB NUMBER (Y reg only> 87 (135) -- OPENED FOR READ ONLY 88 (136) -- END OF FILE 89 (137) -- TRUNCATED RECORD 8A (138) -- DEVICE TIMEOUT (DOESN'T RESPOND) 88 (139) -- DEVICE NAK 8C (140) -- SERIAL BUS INPUT FRAMING ERROR 8D (141) -- CURSOR out-of-range 8E (142) -- SERIAL BUS DATA FRANK OVERRUN ERROR 8F (143) -- SERIAL BUS DATA FRAME CHECKSUM ERROR 90 (144) -- DEVICE DONE ERROR 91 (145) -- BAD SCREEN MODE 92 (146) -- FUNCTION NOT SUPPORTED BY HANDLER 93 (147) -- INSUFFICIENT MEMORY FOR SCREEN MODE A0 (160) -- DISK DRIVE # ERROR Al (161) -- TOO MANY OPEN DISK FILES A2 (162) -- DISK FULL A3 (163) -- FATAL DISK I/O ERROR A4 (164) -- INTERNAL FILE # MISMATCH A5 (165) -- FILE NAME ERROR Ab (166) -- POINT DATA LENGTH ERROR A7 (167) -- FILE LOCKED AS (168) -- COMMAND INVALID FOR DISK A9 (169) -- DIRECTORY FULL (64 FILES) AA (170) -- FILE NOT FOUND AB (171) -- POINT INVALID