Digital Equipment RX8 User manual

RX8/RX11
floppy disk system
maintenance manual
L....------digital equipment corporation. maynard. massachusetts-----......I

~, . .;.,
( RX8/RX11
floppy· disk ,ystem
maintenance:;}manual
(
EK-RXOI-MM-002
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digital equipment corporation · maynard. massachusetl;s

5179,15
Ist Edition, May 1975
2nd Printing (Rev), September 1975 (
3rd Printing, July 1976
4th Printing (Rev), December 1976
Copyright © 1975,1976 by Digital Equipment Corporation
The material. in this manual. is for informational
purposes and
is subject to change without notice.
Digital Equipment Corporation assumes
no respon-
sibility foriuty errors which may appear in this
manual.
Printed in U.s.A.
The following are ,trademarks of Digital Equipment
Corporation,Maynard, Massachusetts:
DEC
DECCOMM
DECsystem-l0
DECSYSTEM-20
DECtape
DEeUS·
DIGITAL
M{\SSBUS
PDP
RSTS
TYPESET-8
TYPESET-II
UNIBUS
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CHAPTER 1
1.1
1.2
1.2.1
1.2.2
1.2.3
1.2.4
1.2.5
1.3
1.3.1
1.3.2
1.3.3
1.3.3.1
1.3.3.2
1.3.3.3
1.3.3.4
1.4
1.5
'1.6
CHAPTER 2
2.1
2.2
2.2.1
2.2.2
2.2.3
2.2.4
2.3
2.3.1
2.3.2
2jj
2,3.4
2.3.5
2.4
2.4.1
2.4.2
2.4.3
2.4.3.1
2.4.3.2
2.4.4
2.5
2.5.1
2.5.2
2.5.3
2.5.3.1
2.5.3.2
2.~.4
CONTENTS
Page
GENERAL INFORMATION
INTRODUCTION
........................ ,.............. 1·1
PHYSICAL DESCRIPTION ..............,.................. 1-1
Rx8E/RXll Interfaces .................•..........••.. 1·2
Microprogrammed Controll~r ..........•....... 0 • • • • • • • • •• 1·2
Read/Write Electronics . . . . . . . . . . . .. . . . . . . . . . . . ~ , 0 , • • • •• 1 ~2
Electro·Mechanical Drive . . . , . . . . . . . . . . . . . " . . . . . . . . . . . ., 1·2
Power Supply ...•...... ,.......................... 1·3
SYSTEMS COMPATIBILITY ...............•.. , .•.. ,........ 1·3
Media •.......•.... , ............... " ....... , . ,. 1·3
Recording Scheme ................................... 1·10
Logical Format ....................... , ...... ; .... , .. 1·10 ,
Header Description ............................••.. 1·10
Data Field Description ........... , •...••...... , ..... HI
Track Usage ......•.. , .... , .........•..• , ...•.• 1·11
CRC Capability ............................•.... 1·12
APPLICABLE INSTRUCTION MANUALS ........... , ... , ... "., .. 1·12
CONFIGURATION ......... , ..........................• 1·12
SPECIFICATIONS
...... , .. ' ............ ~ .... ' •...... , .... 1·13
INSTALLATION
AND OPERATION
PURPOSE AND ORGANIZATION ............... , .. ' .. , ....... , 2·1
SITE PREPARATION ...............................•.... 2·1
Space .............. , ....... , .. , .... , ..••..... o. 2·1
Cabling ..... .' .... , .. , .. , ............. , .. , • . . . . . .. 2·1
AC Power ....,.....................,...... ~ . • , '! 2·1
Fire and Safety Precautions ;.........'.,....... 0 , • • • • • • • •• 2·2
ENVIRONMENTAL CONSIDERATIONS .... . . . . . . . . .. . . . . , . , . . • ., 2·2
General . . . . . . . . . . . . . . . . . . . , . • , . , . . . . . , . . . • • 0 • .., 2·2
Temperature, Relative Humidity .........•..............•. .. 2·3
Heat Dissipation ..................,...........".,.. 2-4
Radiated Emissions ....................,.. " . . . . . . • . .. 2·4
Cleanliness .......•........................•. 0 • • ., 2·4
INSTALLATION ......................•...• ,0 •• 0 • , ••• ,. 2-4
General .. . . . . . . . . . . . . . . . . . .. . . . 0 • • • • • .. • • • • • , • • • '0 2·4
Tools ............,.,................. 0 • • • • • • , " 2·4
Unpacking and Inspection .......,.".........,.,.,....,.. 24
Cabinet.Mounted . . . . . . . . . . . • . . .. . . . . . . : . . . . . , . . .. 24
Separate Container ................,.........,...,..' 2·6
Installation .......................,',.....,........ 2·6
OPERATION ............................,........... 2-8
Operator Control . . . . . . . . . , . . . . . , . . . . . . . • . • . . . . , . . . .. 2·8
Diskette Handling Practices and Precautions ...,....,.......,..... 2·8
Diskette Storage .......................,............. 2·12
Short Term (Available for Immediate Use) ......... , ........ , . 2~t2
LongTerm .. , .................. .' ..... ,., ... , .... 2·12
Shipping Diskettes ...........,.........,.........,.,. 2·12
iii

CHAPTER 3
3.1
3.2
3.2.1
3.2.2
3.2.2.1
3.2.2.2
3.2.2.3
3.2.2.4
3.3
3.3.1
3.3.2
3.3.3
3.3.4
3.3.5
3.3.6
3.3.7
3.3.8
3.4
3.4.1
3.4.2
3.4.3
3.5
3.6
CHAPTER 4
4.1
4.2
4.2.1
4.2.2
4.2.3
4.2.4
4.2.5
4.2.6
4.2.7
4.3
4.3.1
4.3.2
4.3.3
4.3.4
4.3.5
4.3.6
4.4
4.4.1
4.4.2
4.4.3
4.4.4
4.4.5
CONTENTS (Cont)
Page
RXll INTERFACE PROGRAMMING INFORMATION
REGISTER AND VECTOR ADDRESSES . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
REGISTER DESCRIPTION
................................ ..
3-2
RXCS -Command and Status (177170) ...................... . 3-2
RXDB -Data Buffer Register (177172)
..... . . . . . . . . . . . . . . . . . . . 3-3
RXTA - RX Track Address
........................ . 3-3
RXSA -RX Sector Address
.......................... . 3-3
RXDB -RX Data Buffer
........................... . 3-4
RXES - RX Error and Status
......................... . 3-4
FUNCTION CODES .................................... . 3-5
Fill Buffer (000)
................................... . 3-5
Empty Buffer (001)
.................................. 3-5
Write Sector (010)
................................... 3-6
Read Sector
(all) .......................... ,. . . . . . ... 3-6
Read Status (101)
................................... 3-7
Write Sector with Deleted Data (110)
......................... 3-7
Read Error Register Function (111)
.......................... 3-7
Power Fail ....................................... 3-7
PROGRAMMING EXAMPLES ............................... 3-8
Read Data/Write Data
................................. 3-8
Empty Buffer Function
................................ 3-8
Fill Buffer Function
.................................. 3-11
RESTRICTIONS AND PROGRAMMING PITFALLS .................... 3-11
ERROR RECOVERY .................................... 3-11
RX8E INTERFACE PROGRAMMING INFORMATION
DEVICE CODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 4-1
INSTRUCTION SET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Load Command (LCD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 4-2
Transfer Data Register (XDR) , . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 4-2
STR
.......................................... 4-3·
SER
........................................ 4-3
SDN
........................................ 4-3
INTR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
INIT
........................................ 4-3
REGISTER DESCRIPTION
.............. . . . . . . . . . . . . . . .. 4-3
Command Register ........... . . . . . . . . . . . . . . . . . . . . . . .. 4-3
Error Code Register
.................................. 4-4
RXTA - RX Track Address
................•............. 4-5
RXSA -RX Sector Address
.............................. 4-5
RXDB -RX Data Buffer
............................... 4-6
RX Error and Status
.................................. 4-6
FUNCTION CODE DESCRIPTION ............................. 4-7
Fill Buffer (000)
.................................... 4-7
Empty Buffer (001)
......... , . . . . . . . . . . . . . . . . . . . . . . . . .. 4-8
Write Sector (010)
................................. 4-8
Read Sector (011)
................................. 4-9
Read Status (101)
................................. 4-9
iv
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4.4.6
4.4.7
4.4.8
4.5
4.5.1
4.5.2
4.5.3
4.6
4.7
CHAPtERS
5.1
5.1.1
5.1.2
5.1.3
5.1.4
5.1.5
5.2
5.2.1
5.2.1.1
5.2.1.2
5.2.1.3
5.2.1.4
5.2.1.5
5.2.2
5.2.2.1
5.2.2.2
5.2.2.3
5.2.2.4
5.2.2.5
5.2.2.6
5.2.3
5.2.3.1
5.2.3.2
5.2.3.3
5.2.3.4
5.2.3.5
5.2.3.6
5.2.3.7
5.2.3.8
5.2.3.9
5.2.3.10
5.2.3.11
5.2.3.12
5.2.4
5.2.4.1
5.2.4.2
5.2.4.3
CONTENTS (Cont)
Write Deleted Data Sector (110)
..
Read Error Register Function (111)
Power Fail ............ .
PROGRAMMING EXAMPLES .... .
Write/Write Deleted Data/Read Functions
Empty Buffer Function
......... .
Fill Buffer Function . . . . . . . . . .
RESTRICTIONS AND PROGRAMMING PITFALLS
ERROR RECOVERY ............ .
THEORY OF OPERATION
OVERALL SYSTEM BLOCK DIAGRAM
Omnibus to RX8E Interface Signals
Unibus
to RXII Interface Signals
Interface to pCPU Controller Signals
pCPU Controller
to Read/Write Electronics Signals
Read/Write Electronics to Drive Signals .....
DETAILED BLOCK DIAGRAM AND LOGIC DISCUSSION
RX8E Interface
Device Select and lOT Decoder
Interrupt Control and Skip Logic
C Line Select Logic
..... .
Interface Register
...... .
Sequence and Function Control Logic
RX11 Interface
Address Decoder
DataPath Selection
Interface Register
Sequence and Function Control Logic
Interrupt Control Logic
...... .
Vector Address Generator
..... .
Microprogrammed Controller (PCPU) Hardware
Control
ROM and Memory Buffer ..
Program Counter and Field Counter
Instruction Decode Logic
..... .
Do Pulse Generator
........ .
Branch Condition Selector and Control
Scratch Pad Address Register and Scratch Pad
Counter
Input Selector, Counter, and Shift Register
pCPU Timing Generator .....
Sector Buffer and Address Register
CRC Generator and Checker
..
Data Synchronizer and Separator
Output Circuit ....... .
Microprogram Instruction Repertoire
DO Instruction ..
Conditional Branch
Wait Branch
v
Page
4-9
4-9
4-9
· 4-10
· 4-10
· 4-10
· 4-10
· 4-15
· 4-16
5-1
5-2
5-3
54
5-6
5-7
5-8
5-8
5-8
5-8
5-8
· 5-10
· 5-10
· 5-11
· 5-11
· 5-13
· 5-13
· 5-13
· 5-14
· 5-14
· 5-14
· 5-14
· 5-16
· 5.;16
· 5-17
· 5-17
· 5-17
· 5-17
· 5-18
· 5-18
· 5-18
· 5-19
· 5-20
· 5-21
· 5-21
· 5-22
· 5-22

5.2.4.4
5;2.4.5
5.2.5
5.2.6
5.2.6.1
5.2.6.2
5.2.6.3
5.2.6.4
5.2.7
S.2.7.1
5.2.7.2
5.2.7.3
5.2.7.4
CHAPTER 6
6.1
6.2
6.3
6.3.1
6.3.2
6.4
6.4.1
6.4.1.1
6.4.1.2
6.4.2
FigUre No.
1.1
1-2
1·3
1·4
1-S
1·6
1·7
1·8
1·9
1·10
1·11
2·1
2·2
2-3
2-4
2·5
2·6
CONTENTS (Cont)
Page
Open Scratch Pad ................................ 5.22
Jump
....................................... 5.23
Microprogram Flowchart Description ......................... 5.23
Read/Write Electronics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.36
Diskette Position . . . .
.'. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.36
Head Read/Write Circuitry ..•... : ..................... 5.36
Head Load Control and Solenoid Drivers .................... 5.36
Stepper Motor Control and Motor Drivers ............•....... 5.36
Mechanical Drive ..................................•. 5.38
Drive Mechanism ................................. 5.39
Spindle Mechanism . . . . . . . . . . . . . .. . . . . . . . . . .. . . .. . . 5.39
POsitioning Mechanism ............................... 5.39
Head Load Mechal1ism ... ; ...............•.......... 541
MAINtENANCE .
RECOMMENDED TOOLS AND TEST EQUIPMENT .................... 6.1
CUSTOMER CARE ..................................... 6.1
REMOVAL AND REPLACEMENT ............................. 6.2
Module Replacement . . . . . . . . . . . . : . . . . . . . " . . . . . . . . . . . . .
Drive Placement ................................... .
CORRECTIVE MAINTENANCE •.............................
Initialize Errors
10 • • ~ • • • • • • • • • • • • II • • • • • • II • • • • • • • • • • • •
Interface Diagnostic in Memory ....................•....
Diagnostics Not in Memory .......................... .
KM11 Usage ......... ' ......................... ; .. .
ILLUSTRA nONS
6·2
64
6-4
6·4
64
6·9
6·9
Title Page
Floppy Disk System Configuration ................•............ 1.2
Front View ofthe Floppy Disk System ............... '. . . . . . . . . . .. 1.3
M83S7 Module (RX8E Interface) .............................. 14
M7846 Module (RXll Interface) .............................. 1.5
Top View ofthe RXOI ......... . . . . . . . . . . . . . . . . . . . . . . . . . •. 1.6
Underside View of Drive ................................... 1.7
Top View of Drive ...................................... 1-8
Diskette Media ........... '. . . . '. . . . . . . . . . . . . . • . . . . . . . . .. 1.9
Flux Reversal Patterns . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . 1.10
Track Format (Each Track) ................................. 1.10
Sector Format (Each Sector) ..........................•...... 1.11
RXOI ••...............•...•...................... 2.2
Cabinet Layout Dimensions ................................. 2.3
RXOl Shipping Restraints ...........•...................... 2.5
RX8/RXll Unpacking .......•.............. '. . . . . . . . . . . . .. 2.7
RXOI Cabinet Mounting Information ............................ 2-8
Cable Routing, BC05L·15 .................................. 2.9
vi
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Figure No.
2·7
3·1
3·2
3·3
34
3·5
3·6
.3·7
3·8
4·1
4·2
4·3
4-4
4-5
4-6
4·7
4-8
4·9
4·10
5·1
5·2
5·3
54
5·5
5·6
5·7
5-8
5·9
5·10
5·11
5·12
5·13
5·14
5·15
5·16
5.17
5·18
5·19
5·20
5·21
5·22
5·23
5·24
5·25
5·26
6·1
6-2
6·3
ILLUS'tRA nONS (Cont) .
Title .
PlJge
Flexible Diskette Insertion . . . . . . . . . . . . . . . . . . . . . . . . . . • . 2·11
RXCS Fonnat (RXll) ................. . .. ~ • • .. • . • . • . 3·2
RXTA Format (RX1l) .. .. .. .. .. .. .. .. .. .. . .... 3.3
RXSA Format (RXll) . . . . . . . . . . . . .... ,. . . . . • . • .. 3·3
RXDB Fonnat (RXU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . •. 34·
RXES Fonnat (RXl1) ..........•.................... "/ • . .. 34
RXl 1Write/Write Deleted Data/Read Example ..... . . . . • • . . . .• .. 3·9
RXII Empty Buffer Example ...........•..............•• ; .•. 3~1O
RXII Fill Buffer Example ...........................• i'. ; •• '. 3-13
LCD Word Fonnat (RX8E) ......................•...••....• 4·2
Command Register Fonnat (RX8E) ., .... ,....................... 4·3
Error Code Register Fonnat .........•.......•... ~ . . . . . . . . • 44
RXTA Format (RX8E) ........... " ..•.. , . . . . • • . . . •. • . . . .4·5
RXSA Format (RX8E) . . . . , . . . . . . . . . . . . . . • . . . . . . • . • .4·5
RXDB Fonnat (RX8E) ......................................... 4·6'
RXES Fonnat (RX8E) .......................•.......•... , 4-6
RX8E Write/Write Deleted Data/Read Example .............•.••.•.... 4·11 .
RX8E Empty Buffer Example ................•...•........ , .. 4.13
Fill Buffer Example ..................•........ , .........• 4·14
Bus Structure ......................................., 5·1
Omnibus to RX8E Interface Signals ..............•...•.......... 5·2
Unibus to RXll Interface Signals . . . . . . • . . . . . • . • . . . • . . . .. 5·3
Interface to J.lCPU Controller Signals ............. , ...•.....• , .. , .54
J.lCPU Controller to Read/Write Electronics Signals .............,...,... S-6
Read/Write Electronics to Drive Signals .....•..•... ,. • . . • . . . • . • . .. 5·7
RX8E Interface Block Diagram . . . . . . . . . . • .. . • . . .. . . • • . . . •. 5·9'
RXl1 Interface Block Diagram ...............• , ...... ' ..... 5·12
J.lCPU Controller Block Diagram ......... , .............. , ... 5·15
Data and Clock Separation ..................•..•.....•...•.. 5·19
ID Address Mark Data Separation .......•........•...•........ '. 5.20
Initialize and Function Decode Flowchart ........•.. , .......•...... 5·24
Empty and Fill Buffer Functions Flowchart ...........••...........• 5.25
Read Sector and Read Status Functions Flowchart ..••..•..•..• 5·26
Write Sector Function Flowchart ....................,.....,... 5·28
FINDTR Subroutine Flowchart ..........................,.... 5·29
FINDHD and GETDAM Subroutines Flowchart ..................... .. 5·30
HDRCOM, BDSRT, BADHDRRoutines Flowchart ...••.. , .•...• '., .... 5.32
DELAY, FINDSE,
WRTOS, GETWRD Subroutines Flowchart ... , ........... 5~33
STEPHD. WAITRN, MAGCOM Subroutines Flowchart ...........•..••• .. 5·34
DIFand CHKRDY Subroutine Flowchart ............• . .....• , .. 5·35
Read/Write Electronics Block Diagram . . . . . . . . . . • . . . . . , . . • . . . . . . . . 5·37
Disk Drive Mechanical System .................•.....•... ; .... 5·38
Drive Mechanism ...................................,... $-39
Centering Cone and Drive Hub ...........................•.... 5-40
PositiOning Mechanism ., . . . . . . . . . . . . . . . . . . . . . . .. .. . . . . . • . . 540
RXOI. Rear View ..............•............•. ,........... 6·2
Troubleshooting Flow ......... . . . . . . . . . .. . . ; . . . . • .. 6-5
BC05L-15 Cable ....•......................•...•... ~ . •. 6·7

Figure No.
: .. ,
6,.4
6-5
6-6
6-7
Table No.
ILLl~STRATIONS (Coot)
RX8 Status Routine
RXll Status Routine
Title
, KM 11 Maintenance Module Inserted ..
KMll Light and Switch Definitions for RXOI
TABLES
Title
Interface Code/Jumper Configuration .
Device Code Switch Selection .....
CLine Transfer Control Signals
Recommended Tools and Test Equipment
M7727 Connectors
............ .
viii
• .,.a .....
Page
· 6-10
· 6-10
· 6-11
........ 6-12
Page
. 2-10
.. 4-1
. 5-10
6-1
. .. .. 6-3
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