ZXNet эхоконференция «code.zx»

Типичное описание ВГшки. Только для тех, кто по этой фене что-либо понимает. ================================== cut here ================================== FDC 179X documentation ******************************* COMMAND SUMMARY TYPE COMMAND 7 6 5 4 3 2 1 0 I Restore 0 0 0 0 h v r1r0 I Seek 0 0 0 1 h v r1r0 I Step 0 0 1 u h v r1r0 I Step In 0 1 0 u h v r1r0 I Step Out 0 1 1 u h v r1r0 II Read Sector 1 0 0 m S E C 0 II Write Sector 1 0 1 m S E C a0 III Read Address 1 1 0 0 0 E 0 0 III Read Track 1 1 1 0 0 E 0 0 III Write Track 1 1 1 1 0 E 0 0 IY Force Interr.1 1 0 1 I3I2I1I0 FLAG SUMMARY TYPE I COMMAND h = Head Load Flag(Bit 3) h = 1, Load head at beginning h = 0, Unload head at beginning v = Verify flag (Bit 2) V = 1, Verify on destination track V = 0, No verify r1r0 = Stepping motor rate (Bits 1-0) Refer to table I for rate summary u = Update flag (Bit 4) u = 1, Update track register u = 0, No update TYPE II & III COMMANDS m = Multiple record flag (Bit 4) m = 1, Multiple records m = 0, Single record a0 = Data address mark (Bit 0) a0 = 0, FB (Data mark) a0 = 1, F8 (Deleted data mark) E = 15 ms delay (2 MHz) E = 1, 15 ms delay E = 0, no 15 ms delay S = Side select flag S = 1, Compare for side 0 S = 0, Compare for side 1 C = Side compare flag C = 0, disable side select compare C = 1, enable side select compare TYPE IY COMMAND II = Interrupt condition flags (Bits 3-0) I0 = 1, Not-ready to ready transition I1 = 1, Ready to not-ready transition I2 = 1, Index Pulse I3 = 1, Immediate Interrupt I3-I0 = 0, Terminate with no interrupt PROCESOR INTERFACE PIN3 PIN6 PIN5 PIN4 PIN2 CS A1 A0 R/=0 W/=0 0 0 0 status command 0 0 1 track track 0 1 0 sector sector 0 1 1 data data 1 X X H1-Z H1-Z DELAY AFTER WRITE TO COMMAND REG BEFORE READ STATUS MFM = 14 mks FM = 28 mks *NOTE tymes double for 5" drive ADDRESS READED BY READ ADDRESS COMMAND TRACK SIDE SECTOR CRSLENGTH CRC1 CRC2 STATUS REGISTER FORMAT D7 = 1 Ready\n D6 = ? D5 = ? D4 = 1 Sector not found D3 = 1 CRC error D2 = 1 Deleted data mark D1 = 1 Data request D1 = 1 Busy Command Usage Seek Command - Track reg = Actually Track Data reg = Destination Track Read Address - After it Sector reg contains Track # Write Track - Terminated by index pulse NOMINAL VS. WORSE CASE SERVICE TIME density nominal transfer tyme worstcase tyme read write single 64 mks 55.0 mks 47.0 mks double 32 mks 27.5 mks 23.5 mks ================================== cut here ================================== W!7h Be57 W!5hE5, FK0. -+- Доска типа "шик" толщиной 4.00 дюйма.