Oric

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.

Models

Oric-1

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. Both Oric-1 versions had a 16 KB ROM containing the operating system and a modified BASIC interpreter.

Origin of replication

The origin of replication (also called the replication origin) is a particular sequence in a genome at which replication is initiated. This can either involve the replication of DNA in living organisms such as prokaryotes and eukaryotes, or that of DNA or RNA in viruses, such as double-stranded RNA viruses.

DNA replication may proceed from this point bidirectionally or unidirectionally.

The specific structure of the origin of replication varies somewhat from species to species, but all share some common characteristics such as high AT content (repeats of adenine and thymine are easier to separate because their base stacking interactions are not as strong as those of guanine and cytosine). The origin of replication binds the pre-replication complex, a protein complex that recognizes, unwinds, and begins to copy DNA.

Types

The two types of replication origin are:

There are also significant differences between prokaryotic and eukaryotic origins of replication: