The Museum of HP Calculators


This article is Copyright © 1972 by Hewlett-Packard and is used by permission. The article was originally published in the December, 1972 issue of the Hewlett-Packard Journal. If errors crept in during the scanning process, please contact Dave Hicks

A New Series of Programmable Calculators

The three calculators and many peripherals of the 9800 Series are designed to handle the broadest possible range of applications. Flexibility and expandability are emphasized.

By Richard M. Spangler

IN RECENT YEARS, programmable calculators have taken on a large portion of the computation jobs that were previously handled by computers. Calculators have several advantages that are responsible for this trend. Calculators are small, self-contained, and easily transported--they can be brought directly to the user's desk. They are quiet, and fit easily into a laboratory or office environment. No complicated turn-on procedure is required; the user merely turns on the power switch, and the calculator is ready. The most important advantage is a psychological one--calculators are "friendly." They are interactive, they provide immediate feedback and immediate answers, and they are dedicated to their user.

The 9800 Series is a new line of powerful programmable calculators and an extensive set of calculator peripherals. The series is designed to cover a broad range of applications. Important objectives of the new series are to provide the user with a choice of calculators that are flexible and expandable, and to support those calculators with comprehensive applications software and peripherals.

The new 9800 Series is the successor of the 9l00A/B1, HP's first programmable calculators. These earlier calculators were as powerful as the limits of technology at the time of their conception would allow them to be. But with technological advances come better calculators, hence the 9800 Series.

Three Models

There are currently three calculators in the 9800 Series. Model 10 is a key-per-function calculator with a keyboard and language that are extensions of the HP 9100A/B. The display is a three-register numeric display like the 9100A/B's, but uses seven segment light-emitting-diode characters rather than a cathode-ray tube.

Model 20 has a statement-oriented algebraic language. The user doesn't have to position his variables in special registers or keep track of temporary results. He can enter arithmetic expressions in the same order as he would read them, including parentheses. Model 20 even allows implied multiplication, something that's not allowed even in most high-level computer languages. Model 20 has a display of 16 alphanumeric characters that can display a whole statement at a time. The alphanumeric display can be used during program execution to display comments and instructions as well as numeric results. This capability enhances the interactiveness of this model.

Model 30 is even more interactive. The keyboard is alphanumeric, like a typewriter, rather than key-per-function. This complements the 32-character alphanumeric display by making it convenient to enter text and messages. The programming language of the Model 30 is BASIC, a well-known and easy-to-learn computer language that is designed for use in interactive environments.

The electronics of the 9800 Series is general in design and is common to all three calculators. The central processing unit is a microprogrammed, 16 bit serial processor that implements a general computer machine language (see article, page 19). The three separate keyboard languages and the arithmetic routines are implemented by firmware routines stored in MOS read-only memory (ROM), and the user's programs are stored in MOS read-write memory (see article, page 22). The input/output structure is a general purpose system which makes it possible to interface with a wide variety of peripherals (see article, page 24).

Many Peripherals

Some of the more important peripherals that have been interfaced are:

Several general purpose interface cards are also available to interface with other HP instruments, the new HP interface system2, and many peripherals from other manufacturers.

Flexible and Expandable

Flexibility and expandability of the keyboard and programming languages of 9800 Series calculators are provided through the use of add-on ROM modules. From the optional ROMs available, the user can select the language features that are required by his particular discipline.

 

9100A/B

9810A

9820A

9830A

Language

Reverse Polish

Reverse Polish

Algebraic

BASIC

Keyboard

Key per function

Key per function

Key per function

Alphanumeric

ROM size (bytes)

4K

5K to 11K

8K to 14K

15K to 31K

RWM size (bytes)

128(A); 256(B)

908 to 2924

1384 to 3432

3520 to 7616

I/O structure

Special Purpose

General

General

General

User definable
Keys or
functions

None

Optional--
single key
subroutine

Optional--
single key
subroutine or
function with
parameters

Standard--
subroutine
or function
with one
parameter

Recording device

Magnetic card

Card with
Cassette
optional

Card with
Cassette
optional

Cassette
standard

Display

3 register
numeric CRT

3 register
numeric LED

16 character alphanumeric
LED

32 character
alphanumeric
LED

Primary Printer

Optional 16
column
numeric

Optional 16
column
alphanumeric

Standard 16
column
alphanumeric

Optional 80
column
alphanumeric

In Model 10, three ROM blocks of up to 2048 bytes each may be added to the calculator. The first block is used to define and implement the functions of a set of 15 keys on the keyboard. The second and third blocks are for control of internal and external peripherals.

In Model 20, three blocks may be added, each controlling one of three sets of ten keys on the keyboard.

In Model 30, eight blocks may be added, and since the Model 30 has an alphanumeric keyboard, no special keys are required. The ROMs are accessed through mnemonics which are entered as a sequence of alphabetic characters.

Different Models for Different Users

Each of the three calculators is general purpose, but each has features which make it more appealing to different sets of users. Model 10's advantages are its low cost, and its compatibility with the 9100A/B, which provides the basis for an extensive applications program library. For example, the Surveying and Statistics applications packages that were originally developed for the 9100A/B have been updated and expanded to make use of the new features of Model 10.

Its natural algebraic language and its many programming and editing features, such as program flags and relative addressing, make Model 20 ideal for users who want to do their own programming. These features are particularly appealing to research scientists and engineers. The peripheral control capabilities of the Model 20 also make it attractive for use as a controller in instrumentation systems2.

Its larger memory, its array-variable capability, and its built-in tape cassette make Model 30 appealing to users with large programs and data bases, such as structural engineers and investment analysts. The alphanumeric keyboard, string-variable capability, and page-width printer appeal to users in fields outside the scientific, such as education and business. The programming language of the Model 30 appeals to a large number of users who already know BASIC as a time-sharing language. With an optional Terminal ROM, time-share users can transform the Model 30 into a versatile terminal with local as well as remote computation and storage capability.

With all three calculators, each user can specify a system of optional ROMs, peripherals, and read-write memory size to meet his own needs. This versatility is enhanced by user-definable keys, optional on the Models 10 and 20 and standard on Model 30. All three machines can also be expanded by the use of special machine language programs that can be loaded into read-write memory from a magnetic card or cassette. This capability can be used, for example, to supply a software driver for a special peripheral.

The special features of each calculator along with the general purpose nature of the hardware are designed so that some combination of 9800 Series instruments will provide a solution to almost any programmable calculator application.

References

  1. Hewlett-Packard Journal, September 1968.
  2. G. E. Nelson and D. W. Ricci, "A Practical Interface System for Electronic Instruments," Hewlett-Packard Journal, October 1972.


Richard M. Spangler Pick Spangler received his B.S.E.E. degree in 1967 and his M.S.E.E. degree in 1968 from Stanford university. He joined HP in 1968, helped design the 9100B Calculator, then served as project leader for the 9830A firmware. He's now an engineering group leader in the calculator laboratory. His recreational activities aren't unusual for HP Loveland Division engineers; they include mountaineering, water skiing, and bicycling.

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