The Timex Sinclair 2068 was Timex Computer Corporation’s third and last home computer for the United States market.
Launched in November 1983, Timex improved on the ZX Spectrum by adding new features, including:
- an AY-3-8912 sound chip
- two joystick ports
- a keyboard with hard plastic keys
- a cartridge port
- an improved ULA that offered additional screen modes:
- The standard Sinclair 256ร192 mode with a color resolution of 32ร24
- An extended color mode, 256ร192 pixels with color resolution of 32ร192
- A monochrome 512ร192 mode
Advertisements described the TS2068 as having 72K (48K RAM + 24K ROM) of memory, color, and sound.
Although Timex Computer Corporation exited the home computer market in February 1984, an independent division continued to sell and develop the machine in Portugal as the Timex Computer 2068.
Timex/Sinclair 2000
Before Timex launched the TS2068, they showed the TS2000 to the press. The TS2000 was two models: the TS2048 (16K RAM) and TS2072 (48K RAM).
According to David Ornstein, the “TS2000 [used] a Z80A microprocessor running at 3.5mhz. It [contained] a few buffers, either 2 or 6 RAM chips, 2 ROMs, and … a 64-pin custom chip.”
At the time, it wasn’t clear if the models shown to the press were mockups or operational. In Ornstein’s “Perceptions” column in the September/October 1983 issue of Sync, he stated that “I have been using the machine for about 10 months by now, 8-15 hours a day.”
Timex planned suggested retail prices of $199.95 for the TS2072 and $149.95 for the TS2048.
A number of books about the TS2068 were written before Timex launched the TS2068 and refer to the TS2000 instead.
BASIC
Sinclair BASIC was extended with new keywords: STICK, SOUND, ON ERR, FREE, DELETE, RESET. The computer used bank-switched memory, allowing ROM cartridges to replace or supplement the built-in ROM.
These changes made the 2068 incompatible with most Spectrum machine-code software (virtually all commercial titles). Spectrum ROM emulation, available in cartridge and supplemental ROM form, allowed users to run run the majority of software produced for the Spectrum.
Resources
- Timex/Sinclair 2068 User Manual
- Timex Sinclair 2068 Beginner/Intermediate Guide by Fred Blechman
- Timex Sinclair 2068 Intermediate/Advanced Guide by Jeff Mazur
- TS2068 Memory Map and ROM Disassembly by Bob Orrfelt
- The Timex Sinclair 2068 ROM Manuscript by Dr. Lloyd Dreger
Operating System
The TS2068 features a 24K operating system that provided the Basic interpreter, full-channeled I/O facilities, and a function dispatcher that the user could call to have both simple and complex functions performed.
Bank Switching
Bank switching, a means of expanding the computerโs address space, was one of Timex’s main improvements over the ZX Spectrum. The TS2068 could theoretically access up to 256 * 64K, or 16 million bytes of memory.
In practice, the bank switching features supported extending the operating system with special cartridges like Zebra System’s OS64 or moving a BASIC program to cartridge, freeing the entirety of RAM for data.
Display
The TS2068 supports several different display options. They include:
- 32 column display
- 64 column display
- high resolution screen of 256 x 192 pixels
- high resolution screen of 512 x 192 pixels
The machine provides connections for a B&W or color TV, a composite video monitor and an RGB monitor. The last required an adapter.
Keyboard
With the TS2068, Timex introduced a full-size keyboard with 42 hard keys, including a full-sized space bar and two shift keys, one on each size. Unlike the TS1000, it provides real tactile feedback.
Like the TS1000 and Spectrum, the TS2068 keyboard allowed entry of commands and functions with one or a few keystrokes. 26 keys directly entered commands like PRINT, LET, LOAD, SAVE, CLEAR et cetera. The Symbol Shift key gave access to 36 symbols and statements. Shift + Symbol Shift accessed even more and Shift + Symbol Shift followed by Symbol Shift and a key accessed even more.
All told, approximately 126 commands, functions, statements, symbols and graphics were entered via just a few keystrokes.
It’s debatable whether the feature was any faster than directly typing any of them. Given the way the edit window was refreshed with each keystroke, this method was a good compromise.
Like the TS1000 before it, the computer and popular press found the keyboard noteworthy. Neil Shapiro, in an article in Popular Mechanics, referred to the keys as “chiclet” and noted that they were not “full-size typewriter key.” While they were not full-size, they certainly were typewriter keys: the 2068 shared its key style with the Brother EP-20 typewriter.
Resources
The bank switching hardware and software was not fully debugged when the 2068 shipped. Several users have written about the hardware/software issues and proposed solutions.
Technical Specifications
- Z80A CPU at 3.58mhz
- 24K ROM (16K BASIC, 8K EXROM with extensions)
- 48K RAM (32K connected to the Z80, 16K connected through the SCLD)
- AY-3-8910 complex sound generator
- Cartridge (dock) slot for ROM based software and other expansion devices
- 15V DC 1A power supply, center negative barrel connector
References
- Ornstein, David. โPerceptions.โ Sync, October 1983.
Communities
- TS2068@groups.io – email list of 2068 fans
- Timex/Sinclair Place – public group of T/S fans on Facebook
- Timex Sinclair Nostalgia – another public group on Facebook