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Last updated
7 Jan 1998

The Timex Sinclairs


In the early 1980s, as now, the world's biggest computer market was in the United States. It was an essential market for a computer manufacturer. Although Sinclair did sell the ZX81 and Spectrum though mail order in the USA for a time, the Sinclair machines' biggest American success came about through the company's collaboration with Timex.

The American giant was already Sinclair's prime contractor for building ZX81s and Spectrums at its plant in Dundee, Scotland. Sinclair was doing well in the States - by June 1981 it was selling 18,000-20,000 ZX81s a month, more than the combined unit sales of Tandy, Apple and Commodore - but quality problems were dire, with only one in three of the machines actually working. A tie-up with Timex was the obvious answer, and resulted in five officially-licensed clones, produced between 1981-84.

These machines were:

TS 1000

The TS 1000, the first transatlantic Sinclair machine, was intended by Timex to be its saviour - the company was forecast to make a $14 million trading loss in 1982. The machine itself was essentially a ZX81 circuit board in a slightly redesigned case. As in Britain, it was immediately successful, with over 550,000 sold in the six months from its launch in the autumn of 1982.

The familiar Sinclair gremlins struck, however, and the Americans were for some reason less patient than their British cousins. The Wall Street Journal described on 17 Aug 1983 what had gone wrong:

"Although [Timex] quickly sold thousands of computers last fall, early Timex Sinclair buyers faced an immediate disappointment. Almost all the programs written for the Timex machine required a $50 memory unit. But Timex didn't supply that unit in great numbers until two or three months after it introduced the computer. Many new owners would take the machine home without software, plus it in and find it didn't do anything useful. 'It was a disaster,' says the computer buyer at a large discount store chain...

The model 1000 is also irritating to use. If it is jiggled when the memory unit is attached, the television screen hooked up to it sometimes goes blank. The keyboard, drawn on a piece of hard plastic, doesn't have separate keys. The computer also can't produce color graphics or sound and isn't much good for playing games. Consumers who wanted to learn about computers were willing to ignore such shortcomings when the unit was the only one selling for less than $100, but now sales have plummeted."

TS 1500

The TS 1500 (above), launched in August 1983, was a stop-gap between the TS 1000 (whose sales had crashed) and the forthcoming American Spectrum, the TS 2000. It was a ZX81 with an internally-housed 16K RAMpack, in a black and silver Spectrum-style box with the familiar "dead flesh" rubber keyboard. The updating of the ZX81 design was an attempt to counter the two biggest drawbacks of the TS 1000, namely the awful touch-(in)sensitive keyboard and the virtually useless 1K of memory. The machine failed dismally: no matter how much it was dressed up, it was still a ZX81.

TS 2000

The TS 2000, launched in late 1983, was a striking example of how the success or failure of a product could affect the chances of a subsequent product. It was not by any means a bad computer, being essentially a 16K Spectrum in a silver and black box.

However, unlike its hugely popular British sister, the TS 2000 rapidly sunk without trace. This was largely the result of the bad reputation which the TS 1000 had acquired amongst retailers, who had been stuck with vast unsold quantities of the earlier machine after the bottom had dropped out of the low-end market. The chainstores, who were the key to a retail success, didn't want to know about it and the machine died an early death. Its only significant rival, the Commodore 64, subsequently cleaned up the American market.

TS 2048

The TS 2048, released at the same time as the 2000, was the latter machine's big brother, with 48K of memory. It was, in effect, an American version of the UK 48K Spectrum with built-in Kempston-format joystick ports. But, like the TS 2000, it was elbowed out by technologically more advanced computers such as the Commodore 64, and Timex dropped it very quickly.

TS 2068

The fifth and last Timex Sinclair, the TS 2068 (above), was released in November 1983 as a last-ditch attempt by Timex Computer Corp. to stave off its collapse (unsuccessfully - they folded in Spring 1984). It was the only Timex Sinclair machine not to be a more-or-less direct clone of a UK product. Instead, it was a completely different computer derived from the Spectrum, having a larger memory, a Spectrum 128-style sound chip and a cartridge port to the right of the keyboard.

The basic TS 2068 is only partly compatible with the Spectrum. The tape I/O was the same, so you can load Spectrum tape files. Spectrum BASIC is a subset of the TS2068's BASIC, so you can run Spectrum BASIC programs. The TS2068's ROM is different, though, so you can't run Spectrum machine code that makes use of the ROM. Without the aid of a Spectrum emulator, it is possible to run only about 7% of the Spectrum's commercially available software.

The TS 2068's Spectrum emulator is really a Spectrum ROM on cartridge (there are other forms) that is bankswitched into the lower 0-16K region. The top 48K region is filled with RAM. To the software this looks exactly the same as a 48K Spectrum. Using this, it is possible to achieve about 97% compatibility wih a real Spectrum.

The TS 2068's specifications are as follows:

Processor:   Z80A processor clocked at 3.58Mhz
Sound chip:   AY-3-8912 (same as Spectrum 128s) at 1.76475Mhz. It is, however, not attached to the same ports as the AY in the Spectrum 128. The clock rate is also slightly different.
Memory:   72K (48K RAM; 24K ROM) which is bankswitched between three internal 64K memory banks called the HOME bank (16K ROM, 48K RAM), the EXROM bank (8K ROM; this one is not completely decoded and can only hold 8K), and the DOCK bank which is empty and is reserved for cartridges. The memory is bankswitched in 8K chunks.
Operating system:   A superset of 48K Spectrum BASIC (ie - has a few commands added)
Ports:   RF out and composite video available on jacks.
RGB signals available on rear edge connector.
Video modes:   256x192 pixel, 32x24 attributes (Spectrum screen)
256x192 pixel, 32x192 attributes (extended colour mode)
Dual screen mode where you could flip between two Spectrum screens.
512x192 pixel monochrome.
  In good standing
(ZX Computing, Aug/Sept 1983)
*   Sinclair goes to America
(from Sinclair and the Sunrise Technology, chapter 7)