HP series 80


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 with an integrated monitor in a smaller package including storage and printer, at half the price.

Features

The first model of the Series 80 was the HP-85, introduced in January 1980. BYTE wrote "we were impressed with the performance... the graphics alone make this an attractive, albeit not inexpensive, alternate to existing small systems on the market... it is our guess that many personal computer experimenters and hackers will want this machine".
In a typewriter-style desktop case, the $3250 HP-85 contains the CPU and keyboard, with a ROM-based operating system, 16 kB dynamic RAM, a 5-inch CRT screen, a tape drive for DC-100 cartridges, 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 includes four module slots in the back for expansion which can hold memory modules, ROM extensions, or interfaces such as RS-232 and GPIB.
All components were designed at the Hewlett-Packard Personal Computer Division in Corvallis, Oregon, including the processor and core chipset.
Later models offered variations such as different or external displays, built-in interfaces or a rack-mountable enclosure.
The machines were built around an HP-proprietary CPU code-named Capricorn running at 625 kHz and had a BASIC interpreter in ROM. 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 format with a 12-digit mantissa and exponents up to ±499. The interpreter supported a full set of scientific functions at this accuracy. The language supported two-dimensional arrays, and a ROM extension made high-level functions such as matrix multiplication and inversion available.
For the larger HP-86 and HP-87 series, HP also offered a plug-in CP/M processor card with a separate Zilog Z-80 processor.

Historical context

The late 1970s saw the development of inexpensive home computers such as the Apple and TRS-80. Steve Wozniak had developed the Apple computer with the idea of a computer that worked in BASIC when it was turned on, and offered HP rights to the Apple computer. He was turned down and was given a legal release. In an interview he did note that soon after that, the calculator division was starting an 8-bit computer project called Capricorn, and he wasn't allowed to work on that project. Ultimately, the market for desktop computing would go to IBM PC compatible personal computers with a floppy disk drive based operating system, and an industry standard Intel 8088 processor .

Hardware

Models

Model Year Price Remarks
HP-85A1980$3,25016 K RAM, 32 K ROM; 5" CRT, 32×16 text or 256×192 graphics; tape drive, printer
HP-831981$2,250same as HP-85 without printer and tape drive
HP-86A1982$1,795external composite monitor, no tape drive or printer;
two interfaces for 9130 floppy and one Centronics printer port built in; 64 K RAM
HP-871982$ 2,4959" 80×16 display, no printer, no tape, built-in HPIB; 32 K RAM
HP-85B1983$2,995update to HP-85A; 64 K RAM (32 K program/variables, 32 K RAM disk;
I/O, EDISK, and Mass Storage ROM built in
HP-86B1983$1,595update to HP-86; built-in HPIB instead of diskette and Centronics ports; 128 K RAM; EDISK ROM built-in
HP-87XM1983$2,995update to HP-87; built-in HPIB; 128 K RAM
HP-9915A/B1980$1,675industrial 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 from the 85/83 models.
83/8586/87FunctionDescriptionID
00085-1500300087-15003I/OAccess GPIB, serial and parallel interfaces192
00085-15001built-inMass StorageAccess "Amigo" compatible diskette/disk drives on GPIB. Built into 85B and all 86/87 models.208
00085-1500200087-15002Printer / PlotterSupport for external printer/plotter 240
00085-1500500087-15005Advanced ProgrammingExtended Basic commands232,231
n/a00087-15012Electronic DiskUse part of RAM as a disk drive, built into 85B, 86B.209
00085-1500400087-15004MatrixMathematical matrix operations including inversion 176
n/a00087-15004Matrix 2Additional matrix operations177
00085-1500700087-15007AssemblerEdit and assemble Series 80 assembler source40
n/a00087-15011MIKSAMIndexed file record management14
00085-1501300087-15013EMSExtended Mass Storage, access to SS-80 compatible mass storage207
00085-6095200087-60912Service - SystemDiagnostic routines for service/maintenance224
?00087-60913Service - HPIBDiagnostic routines for service/maintenance225
98151An/aProgram developmentSupport HP-9915 front panel, or to emulate it on an 83/858
n/aAKSO-SysextSysextSystem-Extension: structured programming, self modifying code, low level programmierung, made by Andre Koppel Software56

Hardware extensions

82936AROM drawer for up to six of the above ROMs
82903A16 K memory module, for HP-85A only Note: *Do not use with HP-85B, may cause damage*
82908A64 K memory module, for HP-85B or HP-86/87
82909A128 K memory module, for HP-85B or HP-86/87
82900ACP/M System. Contains a Zilog Z80 microprocessor and 64 kilobytes dedicated RAM.
82928ASystem monitor for assembly development. Sets break-points for debugging.
82929AProgrammable ROM drawer for standard EPROMs

Interfaces

The interface modules for the series 80 were built around a proprietary bus interface chip connecting a standard Intel 8049 microcontroller to the main bus. Interface functions such as handshaking were offloaded to the 8049 firmware.
82937AHP-IB Interface
82938AHP-IL Interface
82939ARS-232 Serial interface
82940AGPIO interface
82941ABCD interface
82949APrinter interface
82950AModem
82966AData Link Interface
82967ASpeech synthesis module, 1500-word vocabulary using a Texas Instruments TMS5220 synthesizer chip