HP Series 80

The Hewlett-Packard series 80 of small scientific desktop computers was introduced in 1979, beginning with the popular model 85 targeted at engineering and control applications. They provided the capability of the HP 9800 series desktop computers into a smaller and less expensive form factor. Ultimately, the market for desktop computing would go to industry standard personal computers, such as the IBM PC which would be shortly after the 80 series. Today, Hewlett Packard is one of the largest manufacturers of the standard personal computers which succeeded the 80 series.

Features

The HP-85's typewriter-style desktop case contained a 5" CRT screen, a tape drive (DC-100 cartridges, 210 kB capacity, 650 B/s transfer) and a thermal printer. It could be expanded through four module slots in the back that could hold memory modules, ROM extensions, or interfaces such as RS-232 and GPIB.

The machines were built around an HP-proprietary CPU running at 625 kHz (0.6 MHz, sic) and had a BASIC interpreter in ROM. Programs could be stored on DC-100 cartridge tapes or on disk/tape units connected through GPIB.

Despite the comparatively slow processor, the machines were quite advanced compared to other desktop computers of the time^[1]. The standard number format was a 12-digit (decimal) mantissa with exponents up to ±499, and the interpreter supported a full set of scientific functions at this accuracy.

They also included graphics functions (on screen and hard copy) in the standard model and could easily be expanded in hardware and software - for example, matrix operations could be added to the BASIC interpreter through option ROMs. For the larger HP-86 and HP-87 series, HP also offered a plug-in CP/M processor card.

Models

Model	Year	Price	Remarks
HP-85A	1979	$3,250^[2]	16 K RAM, 32 K ROM; 5" CRT, 32×16 text or 256×192 graphics; tape drive, printer
HP-83	1981	$2,250^[3]	same as HP-85 without printer and tape drive
HP-86A	1982	$1,795^[4]	external composite monitor, no tape drive or printer; 2 interfaces for 9130 floppy & 1 Centronics printer port 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	?	update to HP-85A; 64 K RAM (32 K program, 32 K ramdisk; I/O, EDISK, and Mass Storage ROM built in
HP-86B	?	?	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^[5]	update to HP-87; built-in HPIB; 128 K RAM
HP-9915A/B	1980	?	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
00085-15003	00087-15003	I/O	Access GPIB, serial and parallel (GPIO) interfaces
00085-15001	built-in	Mass Storage	Access Amigo compatible diskette/disk drives on GPIB. Built into 85B, 86, 87.
00085-15002	00087-15002	Printer / Plotter (85) or Plotter (87)	Enhanced printer support including screen-dump to external dot matrix printer
00085-15005	00087-15005	Advanced Prog.	Extended Basic commands
n/a	00087-15012	Electronic Disk	Use part of RAM as a disk drive
00085-15004	00087-15004	Matrix	Mathematical matrix operations including inversion (solving linear equation systems)
00085-15007	00087-15007	Assembler	Edit and assemble Series 80 assembler source
n/a	00087-15011	MIKSAM	File record management
00085-15013	00087-15013	EMS	Access to SS-80 compatible mass storage
00085-60952	?	Service	Diagnostic routines for service/maintenance
98151A	n/a	Program Development	Support HP-9915 front panel, or to emulate it on an 83/85

Hardware extensions

82936A	ROM 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
82967A	Speech synthesis module
82900A	CP/M System (for HP-86/87 only). Contains a Zilog Z80 microprocessor and 64 kilobytes dedicated RAM.
82928A	System monitor for assembly development (essentially the same interface adapter as the 82900A CP/M module, but with different software).
82929A	Programmable ROM drawer for standard EPROMs

Interfaces

82937A	HP-IB Interface (GPIB, IEEE-488, IEC625)
82938A	HP-IL Interface
82939A	RS-232 Serial Interface
82940A	GPIO Interface (general-purpose 4 × 8 bit parallel)
82941A	BCD Interface (parallel, 11 binary coded decimal digits + sign)
82949A	Printer Interface (Centronics parallel)
82950A	Modem (110/300 bit/s, Bell 103/113)
82966A	Data Link Interface (to connect to HP1000/3000 hosts)

External links

Notes

^ e.g. Apple II (1977), Tandy TRS-80 (1977), CBM 2001 (1977), Zenith Z89 (1980)
^ $3,250 in 1980 ≈ $7,600 in 2005 (see Inflation Conversion Factors for Dollars)
^ $2,250 in 1981 ≈ $4,800 in 2005 (ibid.)
^ $1,795 in 1982 ≈ $3,600 in 2005 (ibid.)
^ $2,995 in 1983 ≈ $5,800 in 2005 (ibid.)

[1] .g. Apple II (1977), Tandy TRS-80 (1977), CBM 2001 (1977), Zenith Z89 (1980)

[2] $3,250 in 1980 ≈ $7,600 in 2005 (see Inflation Conversion Factors for Dollars)

[3] $2,250 in 1981 ≈ $4,800 in 2005 (ibid.)

[4] $1,795 in 1982 ≈ $3,600 in 2005 (ibid.)

[5] $2,995 in 1983 ≈ $5,800 in 2005 (ibid.)

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