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For the parent company "Oric Products International", see Tangerine Computer Systems.
Controller and DOS architecture for Oric computers

Oric was the name used by Tangerine Computer Systems for a series of home computers, including the original Oric-1, its successor the Oric Atmos and the later Oric Stratos/IQ164 and Oric Telestrat models (model names stylized in upper case).

With the success of the Sinclair ZX Spectrum, Tangerine's backers had suggested a home computer and Tangerine formed Oric Products International Ltd to develop and release the Oric-1 in 1983. Further computers in the Oric range were released through to 1987 with Eastern European clones being produced into the 1990s.




Based on a MOS 1 MHz 6502A CPU, the Oric-1 came in 16 KB or 48 KB RAM variants for £129 and £169 respectively, matching the models available for the popular ZX Spectrum and undercutting the price of the 48 KB version of the Spectrum by a few pounds. The "48 KB" Oric-1 version was actually 64 KB. The top 16 KB of memory are masked by the BASIC ROM and thus normally not available for the user; The optional disc drive unit contains some additional hardware that allows it to enable or disable the ROM, effectively adding 16 KB of RAM to the machine. This additional memory is used by the system to store the Oric DOS software.[citation needed] Both Oric-1 versions had a 16 KB ROM containing the operating system and a modified BASIC interpreter.

During 1983, around 160,000 Oric-1 computers were sold in the UK, plus another 50,000 in France (where it was the year's top-selling machine). Although not quite the 350,000 predicted, this was enough for Oric International to be bought out and given sufficient funding for a successor model, the Atmos.

The Oric-1 improved somewhat over the ZX Spectrum with a different keyboard design replacing the ZX Spectrum's unusual Chiclet keyboard. In addition the Oric-1 had a true sound chip, the programmable GI 8912, and two graphical modes handled by a semi-custom ASIC (ULA) which also managed the interface between the processor and memory. The two modes were a "LORES" (low resolution) text only mode (though the character set could be redefined to produce graphics) with 28 rows of 40 characters and a "HIRES" (high resolution) mode with 200 rows of 240 pixels above three lines of text. Like the Spectrum, the Oric-1 suffered from attribute clash—albeit to a lesser degree in HIRES mode, when a single row of pixels could be coloured differently from the one below in contrast to the Spectrum, which applied foreground and background colour in 8×8 pixel blocks. As it was meant for the home market, it had a built in television RF modulator as well as RGB output and was meant to work with a basic audio tape recorder to save and load data. Error-checking of recorded programs was bugged, frequently causing user-created programs to fail when loaded back in. An additional feature was a Centronics compatible printer interface.

Oric Atmos[edit]

Oric Atmos

In late 1983 the funding cost for continued development of Oric caused external funding to be sought, and eventually led to a sale to Edenspring Investments PLC.[1] The Edenspring money enabled Oric International to release the Oric Atmos, which added a true keyboard and an updated V1.1 ROM to the Oric-1. The faulty tape error checking routine was still there. Soon after the Atmos was released, the modem, printer and 3.5-inch floppy disk drive originally promised for the Oric-1 were announced and released by the end of 1984. A short time after the release of the Atmos machine, a modification for the Oric-1 was issued and advertised in magazines and bulletin boards. This modification enabled the Oric-1 user to add a second ROM (containing the Oric Atmos system) to a spare ROM-socket on the Oric-1 circuit board. Then, using a switch, the users could then switch between the new Oric Atmos ROM and the original Oric-1 ROM.

Oric Stratos and Oric Telestrat[edit]

Oric Telestrat

Although the Oric Atmos had not turned around Oric International's fortunes, in February 1985, they announced several models including the Oric Stratos/IQ164. Despite their backers putting them into receivership the following day, Oric was bought by French company Eureka, which continued to produce the Stratos[citation needed], followed by the Oric Telestrat in late 1986. In December 1987, after announcing the Telestrat 2, Oric International went into receivership for the second and final time.


Colour printer[edit]

Tangerine's MCP-40 is a plotter with mechanics by Alps Electric.

Prestel adaptor[edit]

The Prestel adaptor produced by Eureaka (Informatika) was the first adaptor produced for the Oric-1 and Oric Atmos computers. However this adaptor was only furnished with very limited software, which was not suitable for the market at that time[vague]. John Henry Patrick Rushton was rumoured[who?] to have hacked the circuit - by meticulously removing the 'security compressed resin' surrounding the circuit board - and apparently discovering the 6522 and its workings[citation needed]. It is also believed[who?] that this is why he had taught himself 6502 assembly language (for the purpose of writing the necessary software, that a local software-house had refused to write for him, when requested[citation needed]). It was then in 1983, that the first fully comprehensive communications software for both the Oric-1 and Oric Atmos was produced (Oricoms and Atcoms - distributed by FGC Publications of Euxton, Preston, U.K.). This software, designed and coded by Rushton and the accompanying manual (which was written by Trevor F Shaw) - both of Telford, Shropshire - utilised the 6522 ACIA (Asynchronous Communications Interface Adaptor, which served as a I/O port controller for the 6502 family of microprocessors). This software (the first of its type for the Oric series of computers and was indeed one of the early pioneers of home computer communications) enabled the Oric-1 and Oric Atmos to communicate with the Prestel videotex system, with Bulletin Boards and facilitated the transfer of files from one Oric-1/Atmos to another, via the public telephone system. The transfer speeds being either 300 or 1,200 baud (this could occur at both full and half duplex). Rushton was later - in the spring of 1984 - to produce the first (for the Oric-1 and Atmos) 'true' high resolution Computer Aided Design (CAD) utilities known as Oricad and Atcad respectively[citation needed].


Pravetz 8D

A Yugoslavian company obtained a licence to make just 5,000 machines. Machines were made, but whether they were under license or not is not known in any detail. It is thought[by whom?] that they assembled parts shipped from the UK. They were Atmos based, the only difference being the logo indicating ORIC NOVA 64 instead of Oric Atmos 48K. Nova had 64 KB of RAM, 16 KB of which was masked by the ROM at startup, leaving 48 KB to work with the BASIC language.

A Bulgarian machine called the Pravetz 8D was produced between 1985 and 1991. The Pravetz is entirely hardware and software compatible with the Oric Atmos. The biggest change on the hardware side is the larger white case that hosts a comfortable mechanical keyboard and an integrated power supply. The BASIC ROM has been patched to host both a Western European and Cyrillic alphabet – the upper case character set produces Western European characters, while lower case gives Cyrillic letters. In order to ease the use of the two alphabets, the Pravetz 8D is fitted with a Caps Lock key. A Disk II compatible interface and a custom DOS, called DOS-8D, were created in 1987-1988 by Borislav Zahariev.

See also[edit]


  1. ^ "The Oric 1 is 30 years old". theregister.co.uk. 28 Jan 2013. Retrieved 30 May 2015. 

External links[edit]