HP 9835A Owner's manual

HEWLETT-PACKARD

HEWLETT ~ PACKARD
Warranty Statement
Hewlett-Packard products are warranted against defects in materials and
workmanship. For Hewlett-Packard Desktop Computer Division products
sold in the U.S.A. and Canada, this warranty applies for ninety (90) days
from date of delivery.* Hewlett-Packard will, at its option, repair or replace
equipment which proves to be defective during the warranty period. This
warranty includes labor, parts, and surface travel costs, if any. Equipment
returned to Hewlett-Packard for repair must be shipped freight prepaid.
Repairs necessitated by misuse of the equipment,
or by hardware,
software, or interfacing not provided by Hewlett-Packard are not covered
by this warranty.
NO OTHER WARRANTY IS EXPRESSED OR IMPLIED, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE. HEWLETT-PACKARD
SHALL NOT
BE LIABLE FOR CONSEQUENTIAL DAMAGES.
*For other countries, contact your local Sales and Service Office to
determine warranty terms.

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Assembly Development ROM
HP 9835A Desktop Computer
Hewlett-Packard Desktop Computer Division
3404 East Harmony Road, Fort Collins, Colorado 80525
. (For World-wide Sales and Service Offices see back of manual.)
Copyright by Hewlett-Packard Company 1979

ii
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System 35 Manual Reference
The following block diagram shows manuals that are included in the System 35 Documentation
scheme and suggested progression. Dotted-line borders indicate those manuals are available
with specific options; solid
borders indicate those manuals that are shipped with every System
35.
~-
r-- --,
I Mass Storage I
Techniques Manual
L-JI-J
,----,
I Mass Storage I
LeriPhera~a.:.a~
Beginner's Guide
Reference Guide
r
I
----
I/O
Programming
Owner's
Manual
~ 7
.JV
VOperating
¢ and
--,
I
Programming Manual
----
r ,
I Assembly I
tanguage Ma:l:J
Preview
<=>
System Test
Manual
----
r Plotter ,
I Programming I
L_ Manual_J
_l!
I --,
I Interface Manuals I
L~JI_J
r------,
IPeripheral Manuals I
L ____ J
iii

iv
Chapter Summaries
Chapter 1. General Information. An introduction to the product and the manual. The pur-
pose and differences of the two Assembly Language ROMs are explained. ROM installation
procedures are given. A glossary is provided, along with a discussion of the syntactical forms
used in the manual.
Chapter 2. Getting Started. A general discussion of the assembly language system. A format
for
the creation of an assembly language program is presented. Topics such as modules,
routines,
and memory allocation are discussed, along with methods of using them effectively.
Also discussed
is the storage and retrieval of modules on mass storage.
Chapter 3. The Processor and the Operating System. Necessary information on the struc-
ture of the processor and the operating system is presented. Topics covered are: machine
architecture,
memory organization, data structures and arithmetic, and the machine instruc-
tions.
Chapter 4. Assembly Language Fundamentals. The basic statements and syntaxes used
throughout the assembly language are discussed. Program entry, assembling, symbolic opera-
tions, module creation, program and variable storage, and utilities are the topics covered.
Chapter 5. Arithmetic. Arithmetic operations are reviewed and the arithmetic utilities are
discussed. Floating point and BCD arithmetic are explained.
Chapter 6. Communicating between Basic and Assembly Language. The techniques used
to pass information to and from the assembly language programs are discussed. Calling assem-
bly routines and passing parameters are presented, along with issues involved with using
common. Applicable utilities are also discussed.
Chapter 7. I/O Handling. The various techniques of handling the receiving and sending of
information
to peripheral devices is presented. Topics are: a review of I/O-type machine
instructions, registers, applicable utilities, interrupts and interrupt service routines,
handshake-type of I/O, direct memory access, and mass storage devices.
Chapter 8. Debugging. Techniques for isolating and correcting logic problems in assembly
programs are discussed. Included in the discussion are techniques for stepping through prog-
rams, getting
dumps, patching, and using the keyboard.
Chapter 9. Errors and Error Processing. A discussion of Assembly Language ROM and
other related errors, and what causes them. Included are methods for trapping errors and
possible methods for correcting them.

v
Table of Contents
Chapter 1: General Information
Structure of the Manual. , .............................. , .............. , ........... 2
Purpose of
the ROMs . . .. ... .... . ............. ,' .... ,' ... ."., .............. 2
ROM Installation .. , .............................................................. 3
Buzzwords
........ , . . . .. , .... " .. " ...... , ........ ,. ..,.,', ..... " .. ,', ... ,., .. 4
Fundamental Syntax
.... , . . . . . .. . .. , ............... , .......... , .... , ... , .... , .... 6
Chapter 2: Getting Started
Developing Routines for Later Use ............. , .................... , .......... , ... 7
Overview . . . . . . . . . . . . . . . . .
............ , ....................... , . . . . . . . . . . . . . . . . 9
Program
Creation. . . . . . . . . . . . . . . . . . . . . .. ... ... . ............. , .............. 9
Program Entry
.......... .......... . .. , ..... , ........ , .. , .................. 14
Other Extensions .... , ...... ,., ...... , ...................................... 16
Modules, Routines, and Such .......... ............ ., ...... , ..... ,..... . ..... 17
Names ..... , , . , ....... , .............. , ..... , ............... , ........ , . . . . . .. 17
Survey of Modules
and Routines .. , .............. , . , . , ........ , ... , ........... 18
Setting Aside Memory .. ,. ....................... ...... .................... 19
Retrieving
and Storing Modules ...................... , ...... , .................... 22
Chapter 3: The Processor and the Operating System
Machine Architecture ........................... , .......... , ..................... 25
Registers .. , .. , .......... , ....... , ........................................... 26
General Memory Organization . , . , .................................. '. . . . . . . . . . 28
Protected Memory . , ............... , ... , .................. ,................. 28
Base and Current Page .......... , ........................ , ................... 29
Data Structures ......................................... , . . . . . . . . . . . . . . . . . . . . . .. 30
Integers ........... , ................... , ......... 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • 30
Strings ....... , ...... , .. , , . . . .. . .. " ...... , ... "." .. " ... , .. ' ... , ... ,.,.... 30
Full-Precision Numbers ... , . , ....... , , ... , .. , .. , ................ , ........ , , .. 31
Short-Precision Numbers. .
.. .., .. ,.",., ...... , .... " ..... ,., ......... , .. ,. 31
Machine Instructions
.... ,., .... , ... , ... , ......... , ........................... ,.. 32
Operands ......... ,., .. , .... , ..... ' ...... ,., ....... , ... " .... " .. " .. " .. 32
Indirect Addressing ........... , , . , .. , . , .. , ... , .. , ... , .. , ................. , . . . 34
Load/Store Group .. , . , .... , .... , ..... , .. , . , ... , , , , .... , ..... , .. , . , .... , , , . , 34
Integer Math Group ........ , , .. , , ..... , ... , ........... , ..... , ................ 35
Branch Group .. , .. , ........ , .. , ................. , ........... , .... , ..... , .... 36
Test/Branch Group ... , .... , ... " .. , ..... , ..... " .......................... ,37

vi
Test/ Alter /Branch Group < < < < < < •• , , • < < , •••• , < ••••• < < •••••••• < ••••• , •••••••• 38
Shift/ Rotate Group < ••••• < < ••••••• , • • ••••••••••••••• <. • ••••••• < •• < •• < • " • 40
Logical Group· ......... < •• < < ••••••••• , •••••• , , •• < •• < •••••••• , •••• < < ••••••••• 41
Stack
Group ..................... . .... < • •• < •••• < ••••• < ••••• < ••••••••••••• 42
BCD Math Group· .......................... , ............ < •••••••• , •••••• , •• < 44
I/O Group ................................ < • < < < ••••• < •••••••• < < < ••••••• ···47
Miscellaneous . , , ....... < •• , , , • , • , • , < < , , < •••• < < , •••••• , • , , ••••••• , ••••••••••• 48
Chapter 4: Assembly Language Fundamentals
Program Entry , .. , ., ., ..... < • , , •••••••• , •••••• , •••••••• , < < ••••• , •••••••• < •• , • < • 49
Assembly Language Source ............. '. " ....................... < •••• < ••• 51
Actions· ... , ................... < ••••••• , •••••• < , •••••••• < ••••••••• , ••••• 51
Labels
.... < < < • , < ••••• , , ••• < •• < ••• , , • • • • • •• • ••• < • , ••••• , ••••••••• , •••••• 51
Comments'
.... , . , . . . . . . . . .. . ... , ... , .... , ... , ...... , < •••••••• < ••••••••• 53
Syntaxing the Source , .. < •• < ••••••• , •••••• < •••••••••••••••••••••••••• < ••••••• 53
Creating Modules .. < •••••• < < < < ••••••• , ••••••• < • < •• , ••••• , ••••• < •• , • , ••••• , ••••• 55
Storage .. < • < , ••••••• < ••••••• < • < < < ••• , , • < •••••••• < •••••••••••••••••••••••• < ••••• 56
Modules ...... < < ••••••••• < < •••••• < •••••••••••••••• , • < ••••• , , •••• , ••• < ••••••• 56
Variables ... , ........ , ................... < ••••••••• '.' • < < • , ••••••••••• , •• < •• 56
Data Generators· ... , < •••• , , • , •••••••• < , •• < , •••• , •••• , •• < < •••••••••••••• , •• , • 57
Repeating Instructions . , . < < • • • • • •• • ••••••• < < • < , •••••• < •• , • •• • < • , •••••••••• , •••• 59
Assembling, ........ , ... , , .. < ••••••• , , •••••• ,. ·······,····,········,··,········60
Effect of BASIC Environments < ••••••••• , •••••••••••••••• , , •••••• , , •• , ••• < • < •• 60
Source Listing Control , .................. , ... , .......... , .. , .... ", ...... < < , • 61
Page
Format· .. < < • • • • • • • , , • , ••••• , • , •••• , ,.,." < , • , ••••• , , , •••••• < •••• 62
Page Length
... , . < < •• < •••• , , • < , •••• < •••• , ••••• < • • • • • •• • •• , •••••••••••••• 63
End-of-Page Control ., < , •• , • •• ' •••• < < •••••••• < ••••••• , • , ••••• , •••••• , .' 63
Page Headings ....... , , ..... , ........ , , . < < , ••••• < < , •••• , , • < < ••••••• , •••• 64
Blank Line Generation .. < ••• , ••••••••••• , , , • < ••••• < < •••••• , < < •••••••• , • , • 65
Non-Listable Pseudo-Instructions
., ..... , .. ",............. ., ..... , ...... 65
Conditional Assembly, ......... , . , .. < < ••••• , •••••••••• , ••••••• , • , ••••• , •••••• 65
Relocation ..... , .. , < •••••••• , •••••• , • , •••••••••••••••• , , , ••••••• < , •• < ••• , ••• 68
Symbolic Operations ,.,.' ................ , .................. , ..... ,., ... < < • • • •• 69
Pre-Defined Symbols .,., ..... , .......... " ...... < < ••• , •••• , •••• , •• , •• , •••••• 69
Defining Your Own .. , . , .. , . < ••••••••••• , ••••• , •••••••• < • • • • • • • •• " •• , •• , •• 71
Literals
.', ... , ............ , ......... < , , • < < ••••• , < ••• , • , < •••••••••••••• , ••••• 72
Evaluation of
Literals, .... , .... , .... , ... , .. < < , • < , ••••• , •• , ••• < < ••••••••••• 72
Nesting Literals ,
......... < ••••••••••• < < •••• < , < ••••••• < •••••••• , , , •••••• < • 73
Nonsensical Uses of Literals· <
•••••••••••••••• < •• < •• , • , •• < •••• , •• , , ••• , • , •• 74
Literal Pools .......... , ... < < •••• , •• < < < •••••••••••••• , ••••••••• , , •••• , •••• 74

vii
Expressions . , . , . , , ... , , ..... , . , . , , . . .. ." ....... , ...... " ....... ,', ....... , 75
External Symbols
and Elements' . , ... , . , , ....... , , , , , ..... , .... , ... , ........ , , 77
Other Absolute Elements' , , . .. . ... ,", .... ,.. .,.., .. , , . , , ... , , . . . . . .. ,., 78
Utilities' ........... . .
.............. " ........ , ....... , .... , .... , ............. 79
Chapter 5: Arithmetic
Binary Coded Decimal ....... , ........ , ......... ' ........ , ............... "., .. 83
Arithmetic Machine Instructions , ..... , .......... " .. " ........ , .. , ......... , ..... 84
BCD Registers· . , .. , , . , , . , ........... , ... ,." .............. ' , ... "' ......... , 84
BCD Arithmetic ... . . . . . . . . . .. ..... . .. , ... , ................ , .. , ... ,., ..... ,. 84
Addition , ..... , ......... ,.... , .... , , . , . . . . . . . . . .. . .... , ................ ,. 85
Ten's Complement for BCD, , ........ , ... , . , , .. , . , .... , ...... , ..... , . , ...... ·86
Floating Point Summations ' . , .... , , ........ , ............. ,.. , ...... " ...... 88
Normalization , ............. , .... , ........ , ........ , ., ,.. .., ...... ,. ··,·89
Rounding ..... ,. .... " .. , .. " ........ ,.. .".. ., ...... , .. " .. '.... ..... 89
Floating Point Multiplication ...... , ......... , .............. ,.,. . ........... 90
Floating Point Division ., ...... , , ... , ... , ....... , , ..... , ......... , .... ,., ... 92
The FDV Instruction ' ., .... . ........ , ..... , ., .. , .. , ........ , .. ,"', .. ,. 94
Thirteen-Digit Dividends' .. . ... , .... , ..... ···,········,·,··············95
Floating-Point Division Example' .... , ... .. . . . . . . . . . . . .. ····,,·····,···96
Arithmetic Utilities' , . , ......... , ...... , , .. ' .. " .. , .... " .. " ...... , ..... ,...... 99
Utility: ReI-math ., .. ,.... ,·······:···············,·······,········,······,99
Utility: Rel-to-int .......... , . " .. ".,., .................................. 102
Utility: Rel-to-sho ' , ........ , .. ' . . . . . . . . . . ., ., ...... " ..... ,.,.,' ... , ... 103
Utility: Int-to-rel .. , .... , ... , ..... , ......... ,.. ." .. " ........... , ..... 104
Utility: Sho-to-rel .'" ... , . , ... , ., ......... , .. "., .... , ....... , ........ ,. 105
Chapter 6: Communication Between BASIC and Assembly Language
The ICALL Statement .. , . . .. , ................ , .. , .......... , ....... , ......... 107
Corresponding Assembly Language Statements ........ , ... , .............. " .. 108
Arguments· ...... , ............. , ' .............. , .... ,. ..,., ..... ".. . ... 109
"Blind" Parameters ................ . .. ,........... . .... , ....... , ...... , . 112
Getting Information
on Arguments ........... " .. ,., ...... , .... , ... , ....... ,. 113
Utility:
Get-info ............... .......... ........... . .... , ........ ,. 114
Retrieving the Value of an Argument ...... ., ...... ,..... . .. , ........ ,. . .. 116
Utility: Get-value ......... ,., ...... , ..... , ............... , ... , ... , .. , .. 117
Utility:
Get-element· . , ' , ..... , , ........ , , .... , , , , .. , . .. , .... ,., ....... 118
Utility: Get-bytes .... , ......... ,., ., .. ,··.··.····,,·················,119
Utility: Get-elem-bytes .. , , . ' , ..... , , ....... , , , ... , ...... , , , .... , ...... 120

viii
Changing the Value of an Argument 0 < < , , " •• 0 0 0 0 •••• , • , , ••••••••••••••••••• , • 122
Utility:
Put-value ... , . 0 • , , ••••••••• , • , ••••• < • < •• , , , • < •• , , < •••• , ••••• < • , 122
Utility:
Put-element, ... , ... , , < •••••• , ••• , , •••••••••••••••••••••• , • , < •• , 123
Utility:
Put-bytes ........ , . , ..... , . , .. < < ••••••• , •••••• , •••••••••••••••• 124
Utility: Put-elem-bytes .... , ...... , , ................................. ", 125
Using Common ........ < •••••• , • •• • ••••• ,', ••• ,.,.", •••••••• , •••••• ,." ••••••• 127
Busy bits
............ , ... , ... " ..... ,., ........ ,. o. • ••••••••••••••••• ,'" •• 130
Utility: Busy. , . . . . . . . . . . .. . ..... , , ......... < • , •••••••••••••• , , • , , •• , , • 131
Chapter 7: I/O Handling
Peripheral-Processor Communication. , , ..... , .. < ••••••••• 0 •••••••••••••••••••••• 133
Interfaces ....... , ........ , , ............ , ... , . , .......................... , . , 134
Registers ., .. " .. , ......... , ....... ', ....... , ........... " .. , ... ,' ......... 134
Select Codes ....... < •• , •• , , ••••• , •• , ••••••••••••••• , •• ,' ••••••• , ••••• , ••• , 134
Status and Control Registers ....... , ....... , .......................... " .... 136
Status and Flag Lines, .... , , .. , ... , " ..... , ......... , .. , .... , ........... , .... 137
Programmed
I/O ...... , , .... " .' ... , .. , ..... , ........................ , ... , .. , 138
Interrupt I/O ... , , .. < • , ••••••• , ,." ••••••••• , •• " •• < < •••••••••• , , • , •• , • " •••• 138
Priorities
.. , ......... < ••••••••••••••••••• , • , ••••••••••••••••••••••••••••• , •• 140
Interrupt Service Routines and Linkage ... < ••••••• , •••••• , •••• , , ••• , ••• ,., ••• 140
Access .... , .. , . ,< ' ••••••• , •••••• , •• ,. < • , ••••••• , •••••••••• , ••••••••• , ••••• 141
Utility:
Isr-access . , .. , ........ , .......... , .... , . , ...... , ............... 143
State Preservation and Restoration ............. , ... , ......... 0 •••••••• ,. ..,. 145
Indirect Addressing in ISRs ,
.................... , .................... , .... , ., 146
Direct Memory Access (DMA) ., .... , .... , .. , .. < • , ••••••••••••••••••••••••••••••• 147
DMA Registers ,.... . ............... ' ................... , ....... " ........ 148
DMA Transfers. , .... , , ...... , ...................... , . . . . .. . ............... 149
BASIC Branching on Interrupts .... " ..... " ........... , .... , .. , .. " ... , ........ 150
ON INT Statement .. , ........................ , . , ..... < , ••••••••••••••••••••• 150
Signalling, .. " .... , ...... , ..... < < , , , ••••• , ••• , • , • , ••••••••••• , , •••••• ,. • ••• 151
Additional Pre-Defined
Symbols, 0 , ••••• , , ••••••••••••••••••• , ••••••••••••••• 153
Prioritizing ON INT Branches ........ , , .. < •••••••• , ••• , ••••••• , ••• , •••••••••• 153
Environmental Considerations
..... , , .... , ....... , .... , ...... , ............... 155
Disabling ON INT Branching ., ....... , .............. ' ............ , ... , ...... 156
Mass Storage Activities . , ...................... , ........................ , ....... 156
Reading from Mass Storage ., .......... , ............... , ..... , ... ,. < • , •••••• 157
Utility: Mm-read-start ...... <. • .••••.....•• , •••••••••••••••••••• " ..• , 158
Utility: Mm-read-xfer .. , ............ , ......... , .... , ......... ,., ..... 159