View source for Engineering:HP 9845C

{{Infobox computer
| Developer    = [[Company:Hewlett-Packard|Hewlett Packard]]
| Photo        = [[Image:HP_9845C.jpg|250px]]
| Type         = [[Engineering:Desktop computer|Desktop computer]]
| Released     = 1980<ref name=hpnet/>
| Discontinued = 1984 (being outcompeted by the {{nowrap|200 series)}}<ref name=hpmus>{{cite web |title=HP Computer Museum |url=http://www.hpmuseum.net/display_item.php?hw=149 |date= |accessdate=2013-06-30}}</ref>
| Processor    = Standard option 1xx:<br />
2 x 16-bit ({{abbr|LPU|Language Processor Unit}},<ref name="9845as">{{cite web |title=The HP 9845 Assembler Project |url=http://www.hp9845.net/9845/projects/assembler/ |date=2010-02-21 |accessdate=2013-07-02}}</ref> PPU) 3-chip hybrid processor with BPC, IOC and EMC<br /><br />
Enhanced option 2xx:<br />
1 x bit-slice processor (LPU)<br />
1 x 16-bit hybrid (PPU)<br />
 @ {{nowrap|5.7 MHz}}<ref name=hpnet/>
| Memory       = 64 - 1600 [[Kilobyte|KB]] RAM<br />{{nowrap|128 KB ROM}}<ref name=hpnet/>
| OS           =
| graphics     = {{nowrap|560 x 455 pixels}} {{nowrap|@ 3 bpp}} {{nowrap|(8 color)}}<ref name=hpnet/>
| power        = Mainframe: {{nowrap|275 W (max),}} {{nowrap|CRT display: 550 W (max)}}<ref name=hpnet/>
| price        = US$39,500 {{nowrap|(today ${{Inflation|US|39500|1980|r=-2|fmt=c}})}}<ref name=hpnet>{{cite web |title=The 9845C |url=http://www.hp9845.net/9845/hardware/9845c/ |date=2012-08-29 |accessdate=2013-06-30}}</ref>
| weight       = {{convert|48.1|kg|lb|abbr=on}}<ref name=hpnet/>
}}

[[File:HP 5061-3001 16 bit Hybrib Processor.jpg|thumb|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 [[Company:Hewlett-Packard|Hewlett Packard]] was one of the first desktop computers to be equipped with a color display and [[Light pen|light pen]] for design and illustration work.  It was used to create the color war room graphics in the 1983 movie ''WarGames''.<ref>{{cite journal |last1=Swartz |first1=Jeffrey |title=Making 'Wargames' computers compute required innovative programming |journal=Mini-Micro Systems |issue=June 1984 |pages=135-145 |url=http://bitsavers.org/magazines/Mini-Micro_Systems/198406_Making_Wargames.pdf}}</ref><ref>{{cite web |url=https://www.hp9845.net/9845/software/screenart/wargames/ |title=Screen Art: War Games |work=hp9845.net}}</ref>

==Features==

The attached HP 98770A color display enabled the color graphics with its own CPU and separate power supply, a [[Vector graphics|vector generator]] based on the AMD2900 [[Bit slicing|bit-slice]] architecture, graphics memory with three planes of {{nowrap|32 KB}} each, the connection interface to the mainframe consists of a direct data bus attachment, and a light-pen logic.<ref name=hpnet/>  {{nowrap|4913 colors}} were available.<ref name=hpnet/>

The system is a [[Endianness|big-endian]] [[16-bit|16-bit]] architecture, the BPC, with roots in the [[HP 2100#2116A overview|HP 2116A]] which were one of the first 16-bit microprocessors created.<ref name="9845arch">{{cite web|title=The 9845 System Architecture |url=http://www.hp9845.net/9845/hardware/architecture/ |date=2013-06-09|accessdate=2013-07-02}}</ref>

The display showed 8 soft keys on the lower end of the screen, 39 alignment controllers behind a door enabled fine tuning of [[Engineering:Cathode ray tube#Convergence and purity in color CRTs|color convergence]].<ref name=hpnet/>

The speed of the builtin BASIC language was accomplished by implementing time critical parts of it in CPU [[Microcode|microcode]].<ref name=hpnet/>

A builtin tape cartridge device with a capacity of 217 kB and transfer speed of 1440 bytes/s enabled storage of data.<ref name=hpnet/>
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.<ref name="9845_handbook">{{cite web|title=9845B/C CE Handbook |url=http://bitsavers.informatik.uni-stuttgart.de/pdf/hp/98xx/09845-90039_CEhbk_Apr84.pdf |date=2009-08-17|accessdate=2013-06-30}}</ref>

{| class=wikitable
|+ 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 ==
* [[Engineering:HP 9800 series|HP 9800 series]] HP desktop computer product line
* HP DC100 - DC100 tape format and drive
* [[LDS-1 (Line Drawing System-1)]]

== References ==
{{reflist}}

== External links ==
* [http://www.hpmuseum.net/display_item.php?hw=149 hpmuseum.net: HP Computer Museum], 98x5 Computers Selection
* [https://web.archive.org/web/20081112082710/http://www.bohemiae.com/museum/calculators/hp9845b/9845b-s1.html archive.org/bohemiae.com: HP 9845B - Summary]
* [http://bitsavers.informatik.uni-stuttgart.de/pdf/hp/98xx/09845-90039_CEhbk_Apr84.pdf uni-stuttgart.de: 9845B/C CE Handbook] (.pdf 2009-08-17)

{{DEFAULTSORT:Hp 9845C}}
[[Category:16-bit computers]]

{{Sourceattribution|HP 9845C}}