HP 9845

The HP 9845 series is a line of desktop computers from Hewlett-Packard. The 9845 models included a CRT display; they were programmed in BASIC.

The 9845 models use big-endian 16-bit NMOS microprocessors, the instruction sets of which have roots in the HP 2116A which were one of the first 16-bit microprocessors created.[1]

9845A/S

The first models, introduced in 1978, were the 9845A and 9845S. The 9845A included 16KB of memory and a tape cartridge drive; the 9845S had 64KB of memory, two tape cartridge drives, a built-in printer, and support for graphics.[2][3]

9845B/T

The 9845B and 9845T models were introduced in 1979. The 9845B included 64KB of memory and a tape cartridge drive; the 9845T had 192KB of memory, two tape cartridge drives, a built-in printer, and support for graphics.[4]

9835A/B

Smaller, lighter models, the 9835A and 9835B, were introduced in 1979. The 9835A had a 25-line, 80-character CRT display with no graphics support; the 9835B had a single-line 32-character LED display. Both models could run most 9845A BASIC programs, and also supported assembly-language programming.[5][6][7]

9845C

HP 9845
DeveloperHewlett-Packard
TypeDesktop computer
Released1980[8]
Introductory price
US$39,500 (today $154,300)[8]
Discontinued1984 (being outcompeted by the 200 series)[9]
CPUStandard option 1xx:

2 x 16-bit (LPU,[10] 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[8]
Memory64 - 1600 KB RAM
128 KB ROM[8]
Graphics560 x 455 pixels @ 3 bpp (8 color)[8]
PowerMainframe: 275 W (max), CRT display: 550 W (max)[8]
Weight48.1 kg (106 lb)[8]

The HP 9845C, introduced in 1980, 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.[11][12]

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.[8] 4913 colors were available.[8]

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.[8]

A builtin tape cartridge device with a capacity of 217 kB and transfer speed of 1440 bytes/s enabled storage of data.[8] 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.[13]

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

Option 200

In 1982, higher-performance versions of the 9845B and 9845C, the Option 200 models, were introduced. They replaced the NMOS microprocessor with an AMD 2900-based processor.[14] The microcode of the 2900-based processor included time-critical versions of the BASIC interpreter, speeding up BASIC programs by up to seven times.[15]

Games

There are four commercial game compilations for the HP 9845 computers, all released from Hewlett-Packard:[16][17] 9845 Computer Games Collection, 9845B Computer Games Library, Computer Games Library Vol. 1 and Monte Carlo Simulation.

See also

References

  1. ^ "The 9845 System Architecture". The HP 9845 Project. 2013-06-09. Retrieved 2013-07-02.
  2. ^ "The 9845A/S". The HP 9845 Project.
  3. ^ Eads, William D.; Walden, Jack M. (April 1978). "A Highly lntegrated Desktop Computer System" (PDF). Hewlett-Packard Journal: 2–11.
  4. ^ "The 9845B/T". The HP 9845 Project.
  5. ^ "The 9835A/B". The HP 9845 Project.
  6. ^ Chumbley, Sandy L. (May 1979). "Extending Possibilities in Desktop Computing" (PDF). Hewlett-Packard Journal: 11–13.
  7. ^ Hallissy, Bobert M. (May 1979). "Assembly Programming Gapability in a Desktop Computer" (PDF). Hewlett-Packard Journal: 18–20.
  8. ^ a b c d e f g h i j k "The 9845C". 2012-08-29. Retrieved 2013-06-30.
  9. ^ "HP Computer Museum". Retrieved 2013-06-30.
  10. ^ "The HP 9845 Assembler Project". 2010-02-21. Retrieved 2013-07-02.
  11. ^ Swartz, Jeffrey. "Making 'Wargames' computers compute required innovative programming" (PDF). Mini-Micro Systems (June 1984): 135–145.
  12. ^ "Screen Art: War Games". hp9845.net.
  13. ^ "9845B/C CE Handbook" (PDF). 2009-08-17. Retrieved 2013-06-30.
  14. ^ "Packages and Options". The HP 9845 Project. High Performance Models.
  15. ^ "The Processors". The HP 9845 Project. The Bit-slice Processor.
  16. ^ Arcade-History
  17. ^ 9845 Games
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