Editing COSMAC VIP

{{Short description|1977 microcomputer}}
{{Infobox information appliance
| name         = COSMAC VIP
| title        =
| aka          =
| logo         =
| image        = RCA Cosmac VIP.jpg
| caption      = RCA Cosmac VIP
| developer    = [[Joseph Weisbecker]]<!-- This is noted in the manual RCA COSMAC VIP CDP18S711 Instruction manual on page 2 -->
| manufacturer = [[Radio Corporation of America|RCA]]
| family       =
| type         = [[microcomputer]]
| generation   =
| releasedate  = {{Start date and age|1977}}
| lifespan     =
| price        = US$275 (Kit)
| discontinued =
| unitssold    =
| unitsshipped =
| media        =
| os           = 4-kilobit (512-byte) in [[read-only memory|ROM]]
| power        = 5[[Volt|V]] [[direct current|DC]] CDP18S023 [[power supply]] @ 600 [[Ampere|mA]]
| soc          =
| cpu          = [[RCA 1802]] processor
| memory       = 2 [[kilobytes|KB]] [[random-access memory|RAM]] (Expandable to 4 KB on board, and 32 KB via an expansion slot)
| storage      = [[Compact Cassette (data)|Compact Cassette]]
| memory card  =
| display      = [[RCA CDP1861|CDP1861/CDP1864]] [[Video Display Controller|video display chip]]
| graphics     =
| sound        = [[loudspeaker|speaker]]
| input        =
| controllers  =
| camera       =
| touchpad     =
| connectivity =
| platform     =
| service      =
| dimensions   =
| weight       =
| topgame      =
| compatibility=
| predecessor  =
| successor    =
| related      =
| website      = <!--{{URL|example.org}}-->
}}
The '''COSMAC VIP''' (1977) was an early [[microcomputer]] that was aimed at [[video game]]s. Essentially, it was a [[COSMAC ELF]] with a supplementary [[RCA CDP1861|CDP1861/CDP1864]] [[Video Display Controller|video display chip]]. For a price of US$275, it could be purchased from [[Radio Corporation of America|RCA]] by [[mail order]]. It came in kit form, and had to be assembled. Its dimensions were 22&nbsp;×&nbsp;28&nbsp;cm, and it had an [[RCA 1802]] processor; along with a crystal [[Clock signal|clock]] operating at 1.76&nbsp;MHz.{{efn|The clock speed of many early microcomputers was derived from the base [[NTSC]] colorburst frequency of 3.5795&nbsp;MHz (315M/88), using a common TV crystal at that frequency or a simple multiple, obtaining e.g. the 1.79&nbsp;MHz used in many [[MOS 6502|6502]]-based machines, reducing costs and simplifying production of colour graphics. The VIP is somewhat unique in ''not'' using a standard NTSC crystal, but a slight deviation to 1.76064&nbsp;MHz, in order to match the even simpler-than-usual timing of the extremely cheap, but also extremely rudimentary "Pixie" video generator chip with the TV signal (as per its contemporaries, a single synchronised clock ran the entire system). It also, for reasons best known to the COSMAC designers, prefers a strict adherence to the 60.00&nbsp;Hz ''field'' timing of interlaced, monochrome 525-line televisions and monitors, even though the system's progressive ''frame''-scan thus enforced a ''line'' rate of 15.72&nbsp;kHz, somewhat lower than both the monochrome and color TV standards. Possibly they mistook the nominal rates of the standard as being maxima - a mistake exposed by most other early computers producing eminently TV-compatible signals of ''approximately'', and often somewhat higher than the nominal color 59.94&nbsp;Hz and 15.734&nbsp;kHz, using standard NTSC crystals and not much more complex circuitry.}} It had 2 [[kilobytes|KB]] (2048 bytes) of [[random-access memory|RAM]], which could be expanded to 4 KB on board, and 32 KB via an expansion slot. Its 5[[Volt|V]] [[direct current|DC]] CDP18S023 [[power supply]] had an output of 600 [[Ampere|mA]]. [[input/output|I/O]] ports could be added to connect to sensors, interface relays, an [[ASCII]] [[computer keyboard|keyboard]], or a [[computer printer|printer]].

The machine connected to either a video monitor or to a [[television|TV]] with video input or by means of an external RF modulator.  The VIP used a CDP1861/CDP1864 video display chip to generate the video output, and sound could be played using its integrated [[loudspeaker|speaker]]. It had a 100 bytes per second [[cassette tape interface]] as well. Programs could be loaded into RAM from tapes, and vice versa. It also had a [[hexadecimal|hex]] keyboard for input, which had 16 keys spanning the hex digits 0 to F. [[light-emitting diode|LED]] indicators were used to display power status and tape input; a third LED along with an on-board beeper were activated by the CPU's 1-bit "Q" register. A run/reset switch was used to start [[Application software|user programs]] or the [[operating system]], respectively.

A simple 4-kilobit (512-byte) operating system was built into its [[read-only memory|ROM]]. It allowed one to type in programs using its hex keyboard, show [[main memory|memory]] contents on its [[display device|display]] (step through the bytes of RAM), and view the values of the [[processor register]]s. The ROM monitor was accessed by holding the "C" key while switching from Reset to Run. The COSMAC VIP was shipped with 20 video games, which were programmed in [[CHIP-8]]. CHIP-8 was an early interpreted [[programming language]] that was used on this machine and other early microcomputers, such as the [[Telmac 1800]].  The video games that were provided came as a list of instructions that had to be typed in by the user.

The COSMAC VIP was created by [[Joseph Weisbecker]] of the [[RCA Laboratories]] in New Jersey. His daughter [[Joyce Weisbecker|Joyce]] created some of the games included with it.<ref name="edwards20171027">{{Cite news |url=https://www.fastcodesign.com/90147592/rediscovering-historys-lost-first-female-video-game-designer |title=Rediscovering History's Lost First Female Video Game Designer | last=Edwards |first=Benj |date=2017-10-27 |work=Fast Company |access-date=2017-10-27 }}</ref> RCA sold a $39 version of [[Tiny BASIC]] on an expansion board.<ref name="dolce198004">{{cite news | url=https://archive.org/stream/kilobaudmagazine-1980-04/Kilobaud_Microcomputing_1980_April#page/n111/mode/2up | title=RCA's VIP Tiny BASIC | work=Kilobaud |date=April 1980| accessdate=23 June 2014 | author=Dolce, Larry | pages=111}}</ref>

A '''VIP II''' version was designed, bundling the VIP with several expansion cards and selling it in fully assembled form. Marketing materials from 1979 refer to a 1980 release, but this never occurred. Several years later the VIP II was equipped with a ROM containing a [[terminal program]] and sold as a portable terminal device under the name [[RCA VP 3000]].

==Notes==
{{notelist}}

==References==
{{reflist}}
;Notes
{{refbegin}}
* The December 1978 [[BYTE magazine]] featured an article on CHIP-8 ("An Easy Programming System") as well as an advertisement for the VIP system.
* The May 1977 [[Dr. Dobb's Journal]] reprinted an article by Joseph Weisbecker ("A Practical, Low-cost, Home/School Microprocessor System") describing the design philosophies and economies that went into designing the VIP—which was at the time called FRED ("Flexible Recreational and Educational Device"). That article originally appeared in the August 1974 [[IEEE]] "Computer" magazine.
{{refend}}

==External links==
* [https://web.archive.org/web/20070930033309/http://www.old-computers.com/museum/doc.asp?c=543 old-computers.com article: Cosmac VIP]
* [http://www.vintagecomputermusic.com/ Recordings of Cosmac VIP playing music]
* [https://archive.today/20130209173133/http://groups.yahoo.com/group/rcacosmac RCA COSMAC Yahoo! Group]
* [http://www.revival-studios.com Revival Studios] Developer of new Chip-8/SuperChip/MegaChip8 games.
* [http://www.emma02.hobby-site.com/ Emma 02] including Cosmac VIP Emulator

[[Category:Early microcomputers]]
[[Category:RCA brands]]