2797 floppycontroller register usage 19871016/wjvg 0 fdc command/status type 1 commands w ......00 6 ms stepping rate w ......01 12 ms stepping rate w ......10 20 ms stepping rate w ......11 30 ms stepping rate w .....1.. verify track# w ....1... load/-unload head at beginning w 0000.... restore (seek track00) w 0001.... seek track# in data-reg w ...1.... update track register w 001..... step (in zelfde richting als vorige) w 010..... step-in (to track76) w 011..... step-out (to track00) type 2 commands w ......1. side1 select and verify w .....1.. 15 ms delay w ....1... sector length (1=std) w ...1.... multiple records w 100....0 read sector w .......1 f8(deleted dam)/-fb(dam) w 101..... write sector type 3 commands w .....1.. 15 ms delay w 11000.00 read adres w 11100.00 read track w 11110.00 write track type 4 commands w .......1 not ready to ready transition w ......1. ready to not ready transition w .....1.. index pulse w ....1... immediate interrupt, requires reset w ....0000 terminate with no interrupt w 1101.... force interrupt status type1,4 type2,3 r .......1 busy busy r ......1. index pulse data request r .....1.. track0 lost data r ....1... crc error crc error r ...1.... seek error record not found r ..1..... head loaded r: record type, w: write fault r .1...... write protect write protect r 0....... drive ready drive ready 1 rw fdc track 2 rw fdc sector 3 rw fdc data (of gewenste track) end