Notes for the Sigma Disk Controllers Two patterns of disk controllers - "10 byte" sense controllers and "16 byte" sense controllers All disks have 1024B (256W) sectors model units/cylinders/heads/sectors type 7240/7242 8 / 203 (3 spare) / 20 / 6 10 byte 24360 7260/7261 15 / 203 (3 spare) / 20 / 11 16 byte 44660 7270/7271 8 / 406 (6 spare) / 20 / 6 10 byte 48720 7275/7276 15 / 411 (7 spare) / 19 / 11 16 byte 85899 7265/7266 15 / 411 (7 spare) / 20 / 11 16 byte 90420 T3281/T3282 15 / 815 / 19 / 11 16 byte 170335 T3281/T3283 15 / 815 / 19 / 17 16 byte 263245 T3281/T3286 15 / 555 / 30 / 17 (16?) 16 byte T3281/T3286F 15 / 555 / 60 / 17 (16?) 16 byte T3281/T3288 15 / 822 / 5 / 17 16 byte 69870 header format 7240 726X/727X/T3281 bytes 0-3 flaw / 0 / C / H flaw / 0'CH / C / H bytes 4-7 S / alt C / alt H / 0 S / alt CH / alt CL'alt H / 0 sense status 7240/7270 bytes 0-3 0'CH / C / H / S most recent address bytes 4-7 M'CS / diag / diag / diag seek intr + current sector bytes 8-11 stat / stat 726X/7275 bytes 0-3 W'0'CH / C / H / S W = write protect, most recent address bytes 4-7 M'R'CS / cnf / stat / 0 M = modifier, R = reserve/release mode bytes 8-11 stat / stat / modi / fiers bytes 12-15 check / bytes / 0'dh / dl 14-15 = difference sense byte 5-6 7240,7270 0-15 header parity check bytes 726X, 7275, T3281 0 1 for dual access 1-3 device type 5 = 7261 6 = 7266 7 = 7276, T3286 4-7 device physical addr (cable position) 0 device fault 1 write fault 2 loss of on cylinder 3 offset polarity 4 airflow loss 5 parity error on device ID byte 6 spindle speed fault 7 positioning servo faulT sense byte 7 7240, 7270 726X, 7275 T3281 0-7 LSB of difference 0 physical address (unique) sense bytes 8-9 7240, 7270 726X, 7275, T3281 0 data parity error check write error 1 check write error data check error 2 sector verif error IOP parity error 3 head verif error data overrun 4 cylinder verif error head addr incr err 5 sec addr !=0 @ hdr wr arm in motion err 6 diff sent to device order parity err 7 sector sel to device test mode err 0 ctrl sel to device seek transfer err 1 head sel to device device unavailable 2 cyl sel sent to device head addr ver err 3 seek forward set sector addr ver err 4 read gate to device cyl addr ver err 5 write/erase to device 726X, 7275: 0 T3281: ctrl overtemp 6 read cyl sel to device channel addr err 7 7240: not used missing on sect 7270: MSB of diff sense bytes 10+ 10-11 modifier bits 12-13 check bytes 14 0'diff high 15 diff low (absolute value) operations 7240 726X 7270 7275 T3281 01 write x x 02 read 2 x x 03 seek x x 04 sense x x 05 check-write x x 07 reserve x 09 header write x x 0A header read x x 0F condition rls intr x 12 read 1 x x 13 select test mode x x 17 release x 1F condition rls intr x 23 release x 33 restore x x 83 seek with interrupt x x B3 restore with interrupt x TIO, SIO, HIO status all 0 interrupt pending 1-2 device state 00 = ready 01 = not operational 10 = reserved 11 = busy 3 1 (automatic) 4 unusual end 5-6 controller state 00 = ready 01,10 = n/a 11 = busy 7 0 TDV status 7240, 7270 726X,7275 T3281 0 data overrun 0 error corrected 1 flaw mark flaw mark flaw mark 2 sector unavailable programming err programming err 3 0 write prot err write prot err 4 header verif error IOP parity err IOP parity err 5 on cylinder operational err operational err 6 seek timeout error verification err verification err 7 header parity error header parity err header parity err AIO status 7240, 7270 726X, 7275, T3281 0 data overrun data overrun 1 0 attn int ack 2 0 rls int ack 3 0 0 4 on sector interrupt on sector intr 5 on cylinder 0 6 seek timeout error seek timeout error 7 0 0 operational status byte (SIO, HIO, TIO, TDV) all 8 incorrect lnt 9 xmit data error 10 xmit memory err 11 mem addr err 12 IOP memory err 13 IOP ctrl err 14 IOP halt 15 0 operational status byte (AIO) all 8 incorrect lnt 9 xmit data error 10 zero byte cnt intr 11 channel end intr 12 unusual end intr 13-15 0