The current configuration on my Timex Sinclair 2068 is:

• 3.58MHz Zilog Z80A microprocessor
• 48kb RAM
• 24kb BASIC ROM

Thanks to Bob Johnson for sending me this information.

Here are some details about the TS2068 from the Hardware Factsheet at the nvg.unit.no site:

- T/S2068 -- American version of the Spectrum. Has an additional 8K extension ROM, cartridge port, two joystick ports and AY-3-8912 sound chip with extra Sinclair BASIC commands to support these devices (STICK, SOUND). Packaged in a hard plastic silver case with nonstandard plastic keys.

The TS2068 is Timex's re-engineered 48K Spectrum. It was released in Fall 1983 just before Timex Computer Corp folded in Spring 1984. A rogue arm of Timex in Portugal continued to sell TC2068s (same as TS2068) and TC2048s (an improved Spectrum - more on this in a sec) until 1989. They, of course, were only allowed to sell in non-Sinclair controlled marketplaces.

Timex recognized that a 48K Spectrum would not continue being competitive in North America for long without changes being made. They developed two computers that were to be North America's debut of the Spectrum. One was called the TS2048 and the other the TS2068. The TS2048 was basically a 48K Spectrum w/ Kempston joystick and the advanced video modes of the TS2068 (see below). The TS2068 was a completely different computer with the Spectrum as its roots. Timex decided to only sell the TS2068. When sales over Christmas 1983 were disappointing, they pulled the plug. Timex of Portugal, no doubt encouraged by the Spectrum's popularity in Europe, continued to sell the TS2068 and offered the TS2048 as the TC2068 and TC2048 in parts of Europe, notably Portugal and Poland (got this info from two fellows from each of those countries who mentioned that the Timex computers were very popular there).

When Timex pulled the plug, they dumped all their surplus TS2068s in Argentina. As for the number of TS2068s manufactured, I remember hearing a figure of 60,000 (but I'm not too sure). I have no idea about how many were sold by Timex of Portugal in Europe. Maybe someone from there will enlighten us?

Here are the features of the TS2068:

• Z80A processor clocked at 3.58Mhz
• AY-3-8912 Sound Chip (same as 128K Spectrums) w/ clock 1.76475Mhz It is attached to different ports compared with the Spectrums, so you don't hear AY music when playing Speccy games (of course, it can be overcome). I mention the clock rate here because it is slightly different from the Spectrum's.
• 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.
• The BASIC is a superset of 48K Spectrum BASIC (ie - has a few commands added).
• A cartridge dock is located under a door on the right side of the computer.
• Two joystick connectors (not compatible with any Sinclair joysticks)
• RF out, Composite video available on jacks. RGB signals available on rear edge connector.
• Hardware was nicely designed to support DMA and memory bankswitching.
• 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

As for Spectrum compatibilty: The tape I/O is 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 m/c that makes use of the ROM. I have found that without the aid of a Spectrum emulator, I can run about 7% of the Spectrum's commercially available software.

The 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. There are a few hardware reasons for incompatibilities (if you are really interested you can check out sna2jlo1.zip on nvg in /pub/sinclair/utils/ts2068 - you'll get a brief overview for reasons for incompatibilities). Using an emulator, I have tried about 400 games available on the net and have found 97% compatibility.