8272

TABLE 1. COMMAND SET (Continued)

I

DATA BUS

PHASE RIW I D7 De D5 D4 D3 D2 Dl DO

SCAN LOW OR EQUAL

Command W MT MFM SK 1 1 0 0 1

W0 0 0 0 0 HDS DSl DSO

WC

WH

WR

I

REMARKS

Command Codes

Sector lD information

prior Command

execution

 

I

 

 

 

DATA BUS

 

 

 

 

PHASE

RIW

07

D6

D5

D4

D3

D2

Dl

DO

REMARKS

 

 

 

 

 

RECALIBRATE

 

 

 

Command

W

0

0

0

0

0

1

1

1

Command Codes

 

W

0

0

0

0

0

0

DSl

DSO

 

Execution

 

 

 

 

 

 

 

 

 

Head retracted to

 

 

 

 

 

 

 

 

 

 

Track 0

W

_____ N

SENSE INTERRUPT STATUS

WEOT

WGPL

WSTP

Execution

Data compared between the FOD and main-system

Command

W

0 0 0 0 1 0 0 0

Command Codes

Result

R

ST 0

Status Information at

 

R

PCN

the end of each seek

 

 

 

operation about the

 

 

 

FDC

 

 

SPECIFY

 

Result

R

STO

Status Information

 

R

STl

after Command

 

R

ST2

execution

 

R

C

 

 

R

H

Sector 10 Information

 

R

R

after Command

 

R

N

execution

 

 

SCAN HIGH OR EQUAL

 

Command W

0 0 0 0 0 0 1 1 Command Codes

W_SPT ___.......---HUT -

W

HLT

• NO

SENSE DRIVE STATUS

Command

W

0

0

0

0

0

1 0

0 Command Codes

 

w

0

0

0

0

0

HDS DSl

DSO

Result

R

 

 

 

ST 3

 

Status Information

Command W MT MFM SK 1 1 1 0 1

W0 0 0 0 0 HDS DSl DSO

WC

WH

WR

WN

WEOT

WGPL

WSTP

Execution

Command Codes

Sector 10 information prior Command execution

Data compared between the FDD and main-system

 

 

 

 

 

 

 

about FoD

 

 

 

 

 

SEEK

 

 

Command W

0

0

0

0

1

1 1

1 Command Codes

W

0

0

0

0

0

HDS DSl

DSO

WNCN

Execution

Head Is positioned

 

over proper Cylinder

 

on Diskette

 

INVALID

Command W

____ Invalid Codes ____ Invalid Command

Result

R

STO

Status Information

 

R

ST 1

after Command

 

R

5T2

execution

 

R

C

 

 

R

H

Sector 10 Information

 

R

R

after Command

 

R

N

execution

 

 

 

Code. (NoOp- FDC

 

 

 

goes Into Standby

 

 

 

Stale)

Result

R

5TO

STO=80

 

 

 

(16)

9-56

Page 371
Image 371
Intel mcs-48 manual Command SET