Daniel Roy’s interest in computers started in high school, where he encountered his first computer. It had a video camera attached to it and he had his photo taken. It was enough to get him hooked. Years later, he received a Sinclair ZX81 as a Christmas gift from his wife. Working late into the evenings, […]
Designing a Video Interface with No Prior Experience Read More »
Timex had several companies to work with in 1983 when they designed the replacement for the Spectrum ULA in the Timex Sinclair 2068. We know that Timex eventually selected NCR to make the SCLD in the 2068 that replaced the ZX Spectrum’s ULA. According to Rex Naden, VLSI Technology actively encouraged Timex to consider their
VLSI Technology SCLD Engineering Samples Read More »
I recently purchased a Timex/Sinclair 2068 that had an 8-pin DIN socket on the back. I figured it might be a connection for an RGB monitor and, as it turns out, I was right. This circuit looked nothing like the other RGB designs I’ve seen. Most of those use transistors to generate the sync signals;
DIY RGB Monitor Connection for T/S 2068 Read More »
The Sinclair ZX81/TS1000 keyboard was widely acknowledged as one of the more challenging aspects of using the computer. As a result, many commercial keyboard replacements were available in the UK and US. A number of the replacements available in the US were imported from the UK, like the dk’Tronics keyboard. The E-Z Key and Suntronics
DIY Keyboards for the ZX81 and TS 1000 Read More »
Jim Payne was one of many small, cottage industry supporters of Timex/Sinclair computers. He wrote several programs for the 1000 and 2068 and started a mail order business to sell them after Timex exited the market in 1984.
Jim Payne and Pheonix Enterprises Read More »
The quality of the Timex/Sinclair 2068 video was never great: It was something some reviewers pointed out as observable on TV screens. Modern technology has only made that more obvious. Problem One: Power One of the major contributors to poor video signal quality is the computer’s power supply. The 2068 has two internal power supplies:
How to Fix 2068 Video Read More »
It is done. I’ve “improved” the 2068 signal as much as I can via converting the RGB to composite. It’s pretty good but not perfect: there’s some ghosting and some halo, both effects of the imperfect conversion/cleaning of the composite signals. However, Don Dindang (maker of the very popular Harlequin Spectrum clone PCBs) turned me
Improved 2068 Video Converter Read More »
Rex Naden was vice-president of research and development at Timex during the time they produced the Timex/Sinclair 1500 and 2068 computers. He spent thirty-five years in the semiconductor industry, holds fourteen US patents and earned his BA, MS and PhD degrees in Electrical Engineering from Rice University. Naden developed his affinity for production at an
Interview with Rex Naden Read More »
If you read enough of the old Timex/Sinclair newsletters, you’ll notice that two printers were especially popular with 2068 owners: the Gorilla Banana/Seikosha GP-100 and the Olivetti PR-2300 “inkjet”. And you may wonder why those two printers were especially popular. A Printer Named Banana The first is easy: Seiko (a relative of Epson) produced the
2068 Users and Odd-ball Printers Read More »
Being retired and finished with my combat pit, I was drawn to get out my ZX81 which had been stored in a plastic tub for 25 years. I was faced with two problems: 1) I had no RF TV sets and 2) did not have a usable cassette recorder. I did the one transistor video
The KoalaPad was a resistive touch pad made for home computers like the Apple II, Atari and Commodre 64, first released in 1983. A few years later, Zebra adapted it for use with the TS 2068. Ironically, the KoalaPad’s ancestor, the PrestoDigitizer, began as a product for the Sinclair ZX-80 and other microcomputers. Innovision PrestoDigitizer
The KoalaPad Comes Full Circle Read More »
