Sharp MZ-3500 service manual Data

Page 50

M 7 3500

Shown below is an enlarged view of data format

sequence Writing starts as soon as the index hole comes

through the index detect hole

	1 Track
Sector 01	Sector 02	Firnl ^p

DATA

DATA

I U

I I )

DA I A

<[ t

I N D E X

\M

Start point

Hatched portion is a recording gap

I D

AM TT HH SS DL CRC CRC

ID section CRC check code

Size of data section

(00) H — 128 bytes

(01) H — 256 bytes

Sector number

Head number

(00) H -» Head 0 (side 0)

(01) H -* Head 1 (side 1)

• Track number

• ID address mark which begins the ID section

7)Formatting

To write the above format (ID section, data section, gap) on an entire surface of a new floppy disk is called formatting

Note 1 Formatting may also be called initialization. The word "initialize" is also used as a software term to clear the data section or to partition data area. Keep the difference between formatting and initializing in mind.

Note 2 Unless formatting has been done on a properly adjusted floppy disk drive unit, an erroe may occur on another floppy disk drive unit

8)Data write procedure

Described next is the procedure to write data on the FD.

(1)The head is moved over the track to be written.

(2)The head is loaded

(3)ID section is read and repeated until the desired section is reached

(4)When the desired ID section is found, data is written on that area (DATA AM is also written )

(5)The data thus written is now checked if it was written correctly (read after write) The respective ID section is read while the media makes a full turn

51

DATA

AM DATA CRC CRC

Data	Data section
	CRC check code

'Data address mark

(or delete address mark)

NOTE The delete address mark

is written to indicate invalid data It is often written on

a new floppy disk as there are no valid data on it

(6)The sector of the identical ID is read and verified with the write data Because of thr pad dftei Ar.'e capability the possibility of an error in the written data is quite low

9)Data read procedure

Described next is the procedure to read data from the FD.

(1)The head is moved over the track tu -^ i ead

(2)The head is loaded

(3)The ID section is read and repeated until the desired sector is reached

(4)When the identical IDsection is found, the <~i-m IP that data section is then read

Image 50

Contents Personal Computer Model Z-350 Memory TimerBACKUP, INIT, COPY, DEBUG, Killall VideoLSI, 1C Cmosic Refer to the page TIN Circuit DiagramSlot Slot2 SFDI/FSdisp PresetSymbol Change DispSystem Basic Area RAMBase UserMZ-1D07 MZ3500 System configuration of Model Software Memory Configuration MS1 = D MSO = 0 LTiming of Reset Signal SD1 System Loading & CP/M ROM-IPLMAO Bank SelectFfff Bank SD3 RAM based BasicOperational description ROMBlock diagram Relation between MMR main memory Main Memory MapperTable below describes address map Main CPU and I/O portThis paragraph discusses main CPU I/O MZ3500 0001Main CPU \m Sub CPU and I/O portAddress BUS Memory mapper MMRSP6102R-001 Block diagramTo Reset CoabSrdy MZ3500 Memory mapper MMR SP6102R-001 signal descriptionRAS ROW Address Select Line Address Select Signal Pin No RO2B IN/OUTRO1B D2 Dl 1 1 1 1 1 0 FE do D4 D3 A7 A6 A5A4A3A2AlAO H E X Uhus 1 O1 1 1 1 0 KI1 Dl Do 17 D6 D5 1 1 1 1 1 1 FF 14 I N D3MZ3500 Memory ROMIPL, RAMCOM, S-RAM select circuit Specification CRTSummary of video display specification AsciDot color designated by Dot pitchBlue Graphic dotCH AI +,! AT A r + + G CH ATKA7 #1 FFF Ascii CGVideo RAM Structure of Vram #0000 Structure of character Vram When read/write from GDC#07FFA Read/write by Z-80 via the GDC 640 x 200 dots display mode 8bit16K FV = 60 HzMaster/slave setup by combination 640 x 400 bits display mode FH = 20.92 kHz FV = 47.3 HzSetup of GCD master/slave O signal switchingCrtc block diagram Graphic V-RAM AddressPage Master slice LSI CSP-1 SP6102C 002 signal description CSH CSP-1 Block Diagram» CK LSI CSP-2 SP6012C-003 Signal Description HSY2 2BLK2DSP2 OUT CSP 2 Block Diagram3r00 CAS OUTGDC Graphic display controller UPD7220 signal description AT~BTI AD15ILC2NK-CLC CSR-1MAGECG Address Select Circuit StructureVsync Circuit descriptionCharacter Vram select circuit BlscSet GDC command code Read/write from the Z-80 to V-RAMWrite C 23H Command Code Vecte C 6CH Command Code Return when all parameters were sentCsrw C 49H -COMMAND Code Fifo Empty?VECTE. Dot address is structured on the screen 60HExplanation Following manner Dot display program example-1Kind of line solid line I T E C 23HP4 88H P5 HH Floppy disk OutlineTJ ILJ n VnVn n nV nnn7 Ci D ci IciData MZ3500 MFD interface block diagram FDC UPD765 22 «- o WindowUPD765 signal description Port used in the MFD interface is as follows Trigger motor on of the timer 555 Selects FDDMZ350C MFM recording method3500 Precompensate Circuit Controls during read, write, seek, and re- calibrateMedia detection Control during seek and recalibrationVFO circuit Purpose String of data Pulses from the FDD Data windowVFO circuit configuration Filter Phase Detector Amplifier WindowMFM Mode BQAFM mode timing chart \\\\ 3DSC Side =Aload Track 10 sector 76 iy 7 EH 77 / FFH\128 Indicates the byte position From the top of directory39 B74 B75 Ii PatatB144 6145 B146 B147 39 B148 B149 B150 B151 1015MZS500 General specificationData transmission format Example 7-bits, even parity, 1 stop bitOFF AC controlsStart 8251 AC MZ3500 Data output controlKTS 3SOO RXEN,UTR , T X E N256 2009 6.3 128Wl -» «--N8253 8253 OUTDAT Printer interfacing circuitAA3 DS7Data transfer timing General description of the parallel interfaceOutput I/O port map Write Hold SET Clock circuit SchematicRead Hold DINMZ3500 PD1990AC Block diagram LSB MSBMmmil » GETE1 JGP I/O 3500S I C SFD 1/FSEC SW2 SW1 On on CE332P OFF on MZ1P02 On OFF IO2824 OFF OFFDipswa FD2\f Canbe in either state Description of each block Block diagramFunctions Switching regulator +5VAlarm generation circuit Timing chartKey Specification of keyboard controlAt rrn Key Key search timing2s 2s22 21 StrobeProtocol Key to sub CPU 132.522.5/-s Keyboard controller basic flow PIN Keyboard controller signal descriptionXTAL1 XTAL2 Reset INT ALE DBO DB7 GNDOn OFF Procedure Sub-CPU sideAbnormal Shared RAMCRT inter face test S C I I 00-FFReady O.H Abnormal test ending1 5 c * O DR O.7 ROM-IPL Main CPU Checker Flow Chart 1/2 Main CPU Checker Flow Chart M? 100101 M7*500Keyboard controller ROM test Keyboard testIPL Flow Chart Error Jump \ Boot Address SystemSEEK, Read Error Load Iocs SEEK& ReadSUB CPU IPL Flow Chart 105LJ LJ LJ LJ LJ LJ LJ R R R R F1LU LU U LJ LlJ LJ U U U J l J J L i J L L j l J J L l J L L lRoB IwCAIO MZ-35OO Parts Guide LI S C R I P T I O N No Parts CodeLED PWB IE--or Ooss-zw N T K MZ-3500Parts Code QcnwConnector S C R I P T I O NParts Code MZ-3500NO. Parts Code A a N a DVH S N 7 4 0 6 N NEWCoos Part S C R I P T I O NMark Rank J9, MZ1K02,1K03,1K04,1K05 Key unit M2-3500LA a SOCLSI RAM NO. Parts CodeD e Tin Parts Code N a aMZ-3500 Sharp Corporation