HP 9845C

HP 9845C

Developer	Hewlett-Packard
Type	Desktop computer
Release date	1980[1]
Introductory price	US$39,500 (today $146,100)[1]
Discontinued	1984 (being outcompeted by the 200 series)[2]
CPU	Standard option 1xx: 2 x 16-bit (LPU,[3] PPU) 3-chip hybrid processor with BPC, IOC and EMC Enhanced option 2xx: 1 x bit-slice processor (LPU) 1 x 16-bit hybrid (PPU) @ 5.7 MHz[1]
Memory	64 - 1600 KB RAM 128 KB ROM[1]
Graphics	560 x 455 pixels @ 3 bpp (8 color)[1]
Power	Mainframe: 275 W (max), CRT display: 550 W (max)[1]
Weight	48.1 kg (106 lb)[1]

HP 5061-3001 16-bit 4-chip hybrid processor used as the LPU & PPU processors in the HP 9845 series computers. Contains the BPC, IOC, EMC and AEC die.

The HP 9845C from Hewlett-Packard was one of the first desktop computers to be equipped with a color display and light pen for design and illustration work. It was used to create the color war room graphics in the 1983 movie WarGames.[4][5]

Features

The attached HP 98770A color display enabled the color graphics with its own CPU and separate power supply, a vector generator based on the AMD2900 bit-slice architecture, graphics memory with three planes of 32 KB each, the connection interface to the mainframe consists of a direct data bus attachment, and a light-pen logic.[1] 4913 colors were available.[1]

The system is a big-endian 16-bit architecture, the BPC, with roots in the HP 2116A which were one of the first 16-bit microprocessors created.[6]

The display showed 8 soft keys on the lower end of the screen, 39 alignment controllers behind a door enabled fine tuning of color convergence.[1]

The speed of the builtin BASIC language was accomplished by implementing time critical parts of it in CPU microcode.[1]

A builtin tape cartridge device with a capacity of 217 kB and transfer speed of 1440 bytes/s enabled storage of data.[1] Average access time for the unit is 6s and a rewind end to end takes 20s. The directory is stored in r/w memory to enable quick access.[7]

Graphics display speed (vectors/sec, overlapped and not clipped)

	Option 1xx	Option 2xx
For/Next	~95	~145
Matrix Plot	~200	~240
Absolute Plot	~5 000	~5 000
Circles/s not clipped	~2	~5

See also

• HP 9800 series HP desktop computer product line
• HP DC100 - DC100 tape format and drive
• LDS-1 (Line Drawing System-1)

References

1. "The 9845C". 2012-08-29. Retrieved 2013-06-30.
2. "HP Computer Museum". Retrieved 2013-06-30.
3. "The HP 9845 Assembler Project". 2010-02-21. Retrieved 2013-07-02.
4. Swartz, Jeffrey. "Making 'Wargames' computers compute required innovative programming" (PDF). Mini-Micro Systems (June 1984): 135–145.
5. "Screen Art: War Games". hp9845.net.
6. "The 9845 System Architecture". 2013-06-09. Retrieved 2013-07-02.
7. "9845B/C CE Handbook" (PDF). 2009-08-17. Retrieved 2013-06-30.

External links

• hpmuseum.net: HP Computer Museum, 98x5 Computers Selection
• archive.org/bohemiae.com: HP 9845B - Summary
• uni-stuttgart.de: 9845B/C CE Handbook (.pdf 2009-08-17)