Sinclair ZX-81

The Sinclair ZX81 came from the genius of Clive Sinclair and his desire to bring computing to the masses. The ZX81 was a simple, rugged and very inexpensive computer sold both as an easy-to-build kit and as a fully assembled system.

This machine was not intended to serve any business functions. It was a home machine from the outset designed with the goal of making computing accessible.

Pictured are the documents that this unit came with. In addition to those I have a metric ton of books and other documentation donated by Trenton Henry.

(Submitted January 30, 2008 17:17:42 by ANDRE)

I would like to correct some errors. SPEED: 3.5 Mhz RAM: 1KB on ZX81, 2KB on TS1000, up to 64KB EXPANSION: Rampack, printer, colorpack, sound, RS232 etc... VIDEO: 32 X 24 (22), 64 X 44, 256 X 192 (software) New software is released every month on the web. There are ZX81 emulators available even for the Nintendo DS and the Sony PSP. Goodby(t)e, ANDRE*** http://www.zx-team.de/andre http://zx81.ordi5.free.fr/andre

(Submitted September 20, 2007 08:19:10 by JOE JAMES)

I HAVE A TS 1500, IT IS IN ITS ORIGIONAL CASE AND LOOKS LIKE IT HAS NEVER BEEN USED, INCLUDES USER MANUAL, CABLES AND A LOT OS OTHER SUPPORT BOOKS. IS THIS WORTH ANYTHING?

(Submitted August 22, 2007 19:43:07 by James G. DuPuy)

I have a ZX-81 that I built, and a TS-1000. I figured a way to connect the video directly into the video amp of a tv for a rock solid picture. I have a 2068 with all the goodies. I used to write a lot of software for them. I also have a QL. The ZX Printer did use the aluminum coated paper but it did not burn the paper, it simply vaporized the aluminum coating to expose the dark paper underneith. The rolls were a bit pricy. The 2040 Timex Printer was thermal and could use the same paper as a printer made by Tandy for their little color computer's printer. I used to repair all this stuff too years back. We had a nice computer group in Cleveland OH. Several of us still meet most months but rarely discuss the TS or Sinclair anymore. All mine still work, however!

(Submitted August 12, 2007 19:42:07 by (a href=mailto:zxspectrum128atgmaildotcom)Bruno Florindo(/a))

I'm a Sinclair collector and I have all the Sinclair machines that were sold, plus all the Timex Sinclair computers. I'm still collecting books, magazines and peripherals. The ts1000.us website has a very active community of TS1000 users. As of today, they're still developing new hardware projects. You can now connect SD cards and Hard Drives to the ZX81/TS1000. One TS1000 is now online as a webserver (using 16K of memory). www.worldofspectrum.org's ftp has scans of the Sync magazine, a must for all Timex Sinclair users. There are thousands of people out there who still use these computers today. Unfortunately the Sinclair scene was never strong in the U.S. Lots of people in the U.S. remember the C64, but not the Timex Sinclair. But in Europe that's another story.

(Submitted July 1, 2007 13:30:38 by Luiz Fernando)

I have a Brazilian version of the ZX-81, a CP- 200, made by Prologica, a Brazilian computer industry. I bought it in 1981, and it was my very first computer. I think it still works, but I haven´t tested it in years. If you´re interested in the appearance of such a computer, tell me and I´ll send you some photos! Regards!

(Submitted May 10, 2007 10:02:54 by Kelly)

Ihave the demo add on they used in stores. Is it worth anything.

(Submitted April 24, 2007 07:35:40 by BillK)

I can remember the TV output of the ZX-80/81 appearing on every TV set in an apartment complex (single, central antenna for all apartments. When the student living upstairs did homework the entire complex could watch the painful progress of text instead of the evening news or Ozzie and Harriet! For more readable output, my Osborne 1a (I think) came with a cable to connect to a TV. I never checked for interference with other TVs.

(Submitted January 6, 2007 13:17:46 by Simon Caygill)

From my earlier posting I was wrong the expansion packs did come from Memotech, not Memorex. I also have the DkTronics Keyboard.

(Submitted December 11, 2006 22:15:31 by David O)

@Maurice,

In the UK, you're right the printer is what you described: The printer was not Thermal as stated. It was operated by Spark Erosion a high voltage spark was scanned across aluminum coated paper burning a black mark on a silver background.

HOWEVER, in the US the printer was a thermal printer. I should know.. I owned one.. :-)

(Submitted November 11, 2006 08:36:25 by maurice)

The printer was not Thermal as stated. It was operated by Spark Erosion a high voltage spark was scanned accross aluminium coated paper burning a black mark on a silver background.

(Submitted August 12, 2006 14:34:16 by Jeff)

I still have my ZX81, though I don't know if it still works...haven't tested in in years. The pre-built unit came with 1K of RAM and the kit came with 2K. I bought the kit and Sinclair shipped it with the WRONG instructions. I had to fight with them to get a replacement. They sent the assembled unit as the repalcement. I was bummed about that because the assembled unit used proprietary RAM chips and the kit used off the shelf stuff that was wired in parallel. You could get 16K of RAM for the kit machine at any electronics store and just wire the chips in parallel. I was 16 when I got my ZX81.

(Submitted August 5, 2006 05:30:05 by (a href=mailto:any)WB(/a))

I don't think Memorex made a ram-pack, wasn't it Memotech? Also, Zebra systems made a serial port and modem for it, which I bought and used to bbs for a couple years. A friend also had something like a 'stringy-floppy' which was a high speed tape drive I think.

(Submitted August 1, 2006 07:35:27 by Simon Caygill)

You will also find that Memorex released a 64K RAM pack and a Hi-Res Graphics pack. Did the MicroDrive work with the '81 or was this only for the Spectrum and QL (both missing from your list)??

(Submitted July 25, 2006 06:33:34 by Silvestre Oliveira)

Hi, please put a picture of Sinc. Get a one in http://www.tozzo.freeserve.co.uk/sinclair/images/ zx8116k.jpg

Tks in advance, Sil

(Submitted July 10, 2006 10:36:04 by (a href=mailto:)sire(/a))

Not every ZX81 was sold as kit, they were also available preassembled. Mine is one of them.

(Submitted May 25, 2006 14:03:02 by downhill_without_brakes)

don't forget - the zx81 was orginally sold as a kit!

(Submitted April 1, 2006 05:34:03 by Andrew Hodson)

tape software

(Submitted October 11, 2005 11:16:16 by SkyZip)

I still own a ZX81, and besides the 16K rampack I also have the original zx81 thermo-printer. I kinda missed that on your page.

Description
Manufacturer	Sinclair Research
Model	ZX81
Date Announced	1981
Date Canceled	Unknown
Number Produced	1 million +
Country of Origin	UK
Price	$200
Current Value	$0 to $50

Specifications
Processor	Zilog Z80
Speed	3 MHz
RAM	1K expandable to 56K
ROM	8K
Storage	External Cassette Tape
Expansion	RAM Packs and not much else
Bus	Single expansion port
Video	Up to 256x192 graphics with additional memory
I/O	Various through the expansion port including Parallel and Serial
OS Options	N/A

Notes	The Sinclair ZX-81 (also sold by Timex as the Timex Sinclair 1000) was a very compact Z80 based machine with a membrane keyboard. It was designed and built to be inexpensive and, as such, it was a very common first computer for many people. THe ZX81 was an upgrade to the ZX80 which had half the ROM.

Related Items in Collection	A few docs and a few cables
Related Items Wanted	Tape player, tape software, etc.