The Hewlett-Packard series 80 of small scientific desktop computers was introduced in 1980, beginning with the popular HP-85 targeted at engineering and control applications. They provided the capability of the HP 9800 series desktop computers in a smaller package including storage and printer, at half the price. Ultimately, the market for desktop computing would go to IBM PC compatible

IBM PC compatible

IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...

 personal computers (the IBM PC was announced shortly after the 80 series).

Features

The first model of the Series 80 was the HP-85, introduced in January 1980. In a typewriter-style desktop case, it contained the CPU and keyboard, 16 kB

Kilobyte

The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...

 dynamic RAM, a 5" CRT

Cathode ray tube

The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...

 screen (16 lines of 32 characters, or 256×192 pixels), a tape drive for DC-100

DC100

The DC100 tape format and drive was developed by Hewlett-Packard and introduced as a data storage mechanism for the HP-9825 programmable calculator. The DC100 tape cartridge was a scaled down version of the DC300 cartridge pioneered by 3M, and represents an early version of what is now referred to...

 cartridges (210 kB

Kilobyte

The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...

 capacity, 650 B

Byte

The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...

/s transfer) and a thermal printer. Both the screen and printer display graphics in addition to text, and the printer can copy anything shown on the screen. The chassis included four module slots in the back for expansion which could hold memory modules, ROM extensions, or interfaces such as RS-232

RS-232

In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...

 and GPIB

IEEE-488

IEEE-488 is a short-range digital communications bus specification. It was created for use with automated test equipment in the late 1960s, and is still in use for that purpose. IEEE-488 was created as HP-IB , and is commonly called GPIB...

.
All components were designed at the Hewlett-Packard Personal Computer Division in Corvallis, Oregon

Corvallis, Oregon

Corvallis is a city located in central western Oregon, United States. It is the county seat of Benton County and the principal city of the Corvallis, Oregon Metropolitan Statistical Area, which encompasses all of Benton County. As of the 2010 United States Census, the population was 54,462....

., including the processor and core chipset.Later models offered variations such as different or external displays, built-in interfaces or a rack-mountable enclosure (see table below for details).

The machines were built around an HP-proprietary CPU code-named “Capricorn

Capricorn (microprocessor)

The Capricorn family of microprocessors was developed by Hewlett-Packard in the late 1970s for the HP series 80 scientific microcomputers. Capricorn was first used in the HP-85 desktop BASIC computer, introduced in January of 1980.- Architecture :...

” running at 625 kHz (0.6 MHz, sic) and had a BASIC interpreter in ROM (32kB). Programs could be stored on DC-100 cartridge tapes or on external disk/tape units.

Despite the comparatively low processor clock frequency, the machines were quite advanced compared to other desktop computers of the time, in particular regarding software features relevant to technical and scientific use. The standard number representation was a floating point

Floating point

In computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...

 format with a 12-digit (decimal) mantissa

Significand

The significand is part of a floating-point number, consisting of its significant digits. Depending on the interpretation of the exponent, the significand may represent an integer or a fraction.-Examples:...

 and exponents up to ±499. The interpreter supported a full set of scientific functions (trigonometric functions, logarithm

Logarithm

The logarithm of a number is the exponent by which another fixed value, the base, has to be raised to produce that number. For example, the logarithm of 1000 to base 10 is 3, because 1000 is 10 to the power 3: More generally, if x = by, then y is the logarithm of x to base b, and is written...

 etc.) at this accuracy. The language supported two-dimensional arrays, and a ROM extension made high-level functions such as matrix multiplication

Matrix multiplication

In mathematics, matrix multiplication is a binary operation that takes a pair of matrices, and produces another matrix. If A is an n-by-m matrix and B is an m-by-p matrix, the result AB of their multiplication is an n-by-p matrix defined only if the number of columns m of the left matrix A is the...

 and inversion available.

For the larger HP-86 and HP-87 series, HP also offered a plug-in CP/M

CP/M

CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...

 processor card with a separate Zilog Z-80 processor.

Models

Model	Year	Price	Remarks
HP-85A	1980	$3,250	16 K RAM, 32 K ROM; 5" CRT, 32×16 text or 256×192 graphics; tape drive, printer
HP-83	1981	$2,250	same as HP-85 without printer and tape drive
HP-86A	1982	$1,795	external composite monitor, no tape drive or printer; two interfaces for 9130 floppy and one Centronics printer port IEEE 1284 IEEE 1284 is a standard that defines bi-directional parallel communications between computers and other devices.-History:In the 1970s, Centronics developed the now-familiar printer parallel port that soon became a de facto standard...  built in; 64 K RAM
HP-87	1982	?	9" 80×16 (256×128) display, no printer, no tape, built-in HPIB; 32 K RAM
HP-85B	1983	$2,995	update to HP-85A; 64 K RAM (32 K program/variables, 32 K RAM disk RAM disk A RAM disk or RAM drive is a block of RAM that a computer's software is treating as if the memory were a disk drive... ; I/O, EDISK, and Mass Storage ROM built in
HP-86B	1983	$1,595	update to HP-86; built-in HPIB instead of diskette and Centronics ports; 128 K RAM; EDISK ROM built-in
HP-87XM	1983	$2,995	update to HP-87; built-in HPIB; 128 K RAM
HP-9915A/B	1980	$1,675	industrial rack-mount version of HP-85A/B without screen or keyboard, I/O ROM and Program Development ROM built in

ROM extensions

Note: The HP-86/87 series used different ROMs (yellow labelling) from the 85/83 models (white labelling).

83/85	86/87	Function	Description	ID
00085-15003	00087-15003	I/O	Access GPIB, serial and parallel (GPIO) interfaces	192
00085-15001	built-in	Mass Storage	Access "Amigo HP 300 The HP 300 "Amigo" was a computer produced by Hewlett Packard in the late 1970s based loosely on the stack-based HP 3000, but with virtual memory for both code and data... " compatible diskette/disk drives on GPIB. Built into 85B and all 86/87 models.	208
00085-15002	00087-15002	Printer / Plotter	Support for external printer/plotter (on 86/87 needed for plotter only)	240
00085-15005	00087-15005	Advanced Programming	Extended Basic Rocky Mountain BASIC Rocky Mountain BASIC is a dialect of the BASIC programming language created by Hewlett-Packard. It was especially popular for control of automatic test equipment using GPIB...  commands	232,231
n/a	00087-15012	Electronic Disk	Use part of RAM as a disk drive RAM disk A RAM disk or RAM drive is a block of RAM that a computer's software is treating as if the memory were a disk drive... , built into 85B, 86B.	209
00085-15004	00087-15004	Matrix	Mathematical matrix operations including inversion (solving linear equation systems)	176
n/a	00087-15004	Matrix 2	Additional matrix operations	177
00085-15007	00087-15007	Assembler	Edit and assemble Series 80 assembler source	40
n/a	00087-15011	MIKSAM	Indexed file record management	14
00085-15013	00087-15013	EMS	Extended Mass Storage, access to SS-80 compatible mass storage	207
00085-60952	00087-60912	Service - System	Diagnostic routines for service/maintenance	224
?	00087-60913	Service - HPIB	Diagnostic routines for service/maintenance	225
98151A	n/a	Program Development	Support HP-9915 front panel, or to emulate it on an 83/85	8

Hardware extensions

82936A	ROM Read-only memory Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...  drawer for up to 6 of the above ROMs (max 1 per unit)
82903A	16 K Memory module, for HP-85A only (max 1 per unit)
82908A	64 K Memory module, for HP-85B or HP-86/87
82909A	128 K Memory module, for HP-85B or HP-86/87
82900A	CP/M CP/M CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...  System (for HP-86/87 only). Contains a Zilog Z80 Zilog Z80 The Zilog Z80 is an 8-bit microprocessor designed by Zilog and sold from July 1976 onwards. It was widely used both in desktop and embedded computer designs as well as for military purposes...  microprocessor and 64 kilobyte Kilobyte The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information... s dedicated RAM.
82928A	System monitor for assembly development. Sets break-points for debugging.
82929A	Programmable ROM drawer for standard EPROM EPROM An EPROM , or erasable programmable read only memory, is a type of memory chip that retains its data when its power supply is switched off. In other words, it is non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages... s

Interfaces

The interface modules for the series 80 were built around a proprietary bus interface chip connecting a standard Intel 8049 microcontroller

Intel 8048

The MCS-48 microcontroller series, Intel's first microcontroller, was originally released in 1976. Its first members were 8048, 8035 and 8748....

 to the main bus. Interface functions such as handshaking were offloaded to the 8049 firmware

Firmware

In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices...

.

82937A	HP-IB IEEE-488 IEEE-488 is a short-range digital communications bus specification. It was created for use with automated test equipment in the late 1960s, and is still in use for that purpose. IEEE-488 was created as HP-IB , and is commonly called GPIB...  Interface (GPIB, IEEE-488, IEC625)
82938A	HP-IL HP-IL The HP-IL , was a short-range interconnection bus or network introduced by Hewlett-Packard in the early 1980s. It enabled several devices such as printers, floppy disk drives, tape readers, etc...  Interface
82939A	RS-232 RS-232 In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...  Serial Interface
82940A	GPIO Interface (general-purpose 4 × 8 bit Bit A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...  parallel)
82941A	BCD Interface (parallel, 11 binary coded decimal digits + sign)
82949A	Printer Interface (Centronics parallel interface IEEE 1284 IEEE 1284 is a standard that defines bi-directional parallel communications between computers and other devices.-History:In the 1970s, Centronics developed the now-familiar printer parallel port that soon became a de facto standard... )
82950A	Modem (110/300 bit/s, Bell 103 Bell 103 modem The Bell 103 modem or Bell 103 dataset was the second commercial modem for computers, released by AT&T in 1962. It allowed digital data to be transmitted over regular unconditioned telephone lines at a speed of 300 bits per second. It followed the introduction of the 110 baud Bell 101 dataset in... /113)
82966A	Data Link Interface (to connect to HP1000/3000 HP 3000 The HP 3000 series is a family of minicomputers released by Hewlett-Packard in 1973. It was designed to be the first minicomputer delivered with a full featured operating system with time-sharing. The first models were withdrawn from the market until speed improvements could be made. It ultimately...  hosts)
82967A	Speech synthesis module, 1500-word vocabulary using a Texas Instruments TMS5220 synthesizer chip

External links

• series80.org
• http://www.hpmuseum.org/hp85.htm
• http://hpmuseum.net/exhibit.php?class=1&cat=9
• http://www.vintagecomputers.freeserve.co.uk/hp85/
• HP-85 pictures from all sides
• Repairing the HP-85 tape drive
• Series 80 Listings and Files hosted at AKSO
• HP Series 80 Configuration Guide hosted at www.computercollector.com
• Page WEB française Page perso d'un utilisateur du HP86, périphériques, programmation, transfert de fichiers, photos... (français)
• English WEB page HP86 user WEB page with photos, peripherials, programmation, file transfer... (english)