Sinclair ZX81 turns 30! Do you have one?

bartman (Bart) · #1 19-03-2011, 01:18 AM

Wow !!!!!!
The Sinclair ZX81 turned 30!!!!http://www.iceinspace.com.au/forum/....s/thumbsup.gif
Those of you who go...... "WTF is a ZX81???????"......http://www.iceinspace.com.au/forum/....eyepopping.gif
well here is a link ....

http://www.bbc.co.uk/news/magazine-12703674

I started of with one of these beauties way back and like the article said ....pestering the parents ( in my case just mum) for the puter and then the expansion pack....
I managed to write a program to play Yatzee ( if anyone remembers the game with dice....http://www.iceinspace.com.au/forum/....estionicon.gif) and sure enough as the article says .... lots of frustration with loading and saving to a tape drive!!!!http://www.iceinspace.com.au/forum/....milies/mad.gif

Anyhoooo, here are a few pics of my ZX81 plus 16KB expansion pack....
Dug it up out of a storage box and also found my First mobile phone, an Ericsson GH 337 wit a fancy antenna http://www.iceinspace.com.au/forum/..../winking70.gif.

Let me know if I'm not the only owner of a ZX81 in Australia ( well I guess in the IIS community at least...)http://www.iceinspace.com.au/forum/..../confused2.gif

5: rem "print bartman onto the screen indefinitely"
10: print "bartman";
20: goto 10
30: end(.....mmmm did not need that I guess)

I think that was the BASIC code that I first used .... Please correct me if I'm wrong.....

Bartman

MrB (Simon) · #2 19-03-2011, 04:59 AM

No I didn't have one, but as a kid I always looked at the adverts in the magazines and dreamed.
I always ended up with the hand-me-downs from friends and family... Vic20, C64 etc
Wish I still had them.

Quote:

30: end(.....mmmm did not need that I guess)

lol no, but it is good programing practice

bojan · #3 19-03-2011, 07:16 AM

Quote:

Originally Posted by bartman

Let me know if I'm not the only owner of a ZX81 in Australia ( well I guess in the IIS community at least...)http://www.iceinspace.com.au/forum/..../confused2.gif

5: rem "print bartman onto the screen indefinitely"
10: print "bartman";
20: goto 10
30: end(.....mmmm did not need that I guess)

I think that was the BASIC code that I first used .... Please correct me if I'm wrong.....

Bartman

Well, as far as I am concerned, you are sill the only one

.. Because mine is in a basement somewhere in Europe..(if !)
Actually I used to have two (because I managed to burn ULA chip on the first one when trying to make the printer for it).
It was fun... I made 16kB extension (using static RAM's) and some other things...

Later, I made Apple][ and never looked back

Yes, it was BASIC.. so called 8kBASIC, ZX81 version.

CraigS · #4 19-03-2011, 07:25 AM

No Zx81 .. but I was a Dick Smith Mini Scamp man ! (The kit with the National Semiconductor SC/MP CPU ..and you had to program it from the switches on the front panel !)

… Made my own … none of this buy someone else's product !

I wanted to know how it all worked !

Still have it kicking around somewhere, too.

Cheers

seeker372011 (Narayan) · #5 19-03-2011, 07:50 AM

I had a Timex Sinclair which I bought in the US-wasn't it the same thing? , but sadly don't know where it is now-i gave it away to someone
wish I had kept it!
yes it was fun writing stuff in BASIC
had to hook it up to a TV and save to a cassette player
Narayan

CraigS · #6 19-03-2011, 08:07 AM

I think my Scamp ended up getting a Basic interpreter built into it, also. Yes .. that's right … burnt into one of the first EPROMs !

I also built a keyboard ASCII encoder for it as well …

I should save this beast from becoming lost … its already what … 35 years old!!!

Cheers

Barrykgerdes · #7 19-03-2011, 08:20 AM

Quote:

Originally Posted by CraigS

No Zx81 .. but I was a Dick Smith Mini Scamp man ! (The kit with the National Semiconductor SC/MP CPU ..and you had to program it from the switches on the front panel !)

… Made my own … none of this buy someone else's product !

I wanted to know how it all worked !

Still have it kicking around somewhere, too.

Cheers

My friend who worked at NSC in Scotland gave me an experimental scamp kit to play with. I made a display and keyboard out of an old(?) calculator. I spent hours trying to get it to do something but gave up in the end. The year 1976.

In 1982 I bought a sega 8 bit computer that ran Sega BASIC. It saved to tape but was very unreliable. I later bought the accessories disk drive unit that was much better. With the disk drive I was able to load CPM and had a 40 character wide version of Wordstar. I think the computer is still stored somewhere in Adelaide.

The next computer I had was about 1984. It was 8/16 bit, two FDD and ran DOS 2.11. I later added a HDD, DOS 6.22, 1.44Mb drive and VGA screen. It is still operational. I have Symphony and dataflex loaded on it and can turn it on, check the Database in approximately the same time it takes to load load XP on a modern computer. Those old computers used their limited resources much better than the modern ones.

Barry

AdrianF (Adrian) · #8 19-03-2011, 08:53 AM

My first PC was a Sinclair with no expansion pack. Bought the 16k expansion pack later. It was amazing what could be done on so little memory.
Graduated to a C64 and then a series of TRS80's CoCo's (1,2 and 3).

Adrian

kustard (Simon) · #9 19-03-2011, 09:07 AM

I had a TI99/4A whilst all my friends had VIC20's and CBM64's... I had to write my own games and taught myself how to program on it.

I remember seeing a Sinclair once on a trip to Sydney but it was the XZ Spectrum and not the ZX81.

CraigS · #10 19-03-2011, 10:25 AM

So folks .. which of all these computers would be the oldest (most original) ?

Love to know (just out of interest).

I think my scamp dates back to what Barry mentions .. about 1976.

The Sinclair was pretty early in the piece but was only available in the UK/Europe, originally, (as I recall).

Cheers

Barrykgerdes · #11 19-03-2011, 11:17 AM

I think the NSC SCMP (National Semi Conductors Micro Processor) was the first reasonably successful micro processor chip released circa 1975. There were a number of published circuits in electronics magazines around 1976-77 that used it. However Motorola was not far behind and then came the very successful Z80. I think about 1979, someone may like to research it.

Prior to the micro processor there were some "computer kits" using TTL etc components that used teleprinters for terminals. A friend of mine had one in 1974 that played startrek. Did anyone else have one? I was not very interested in computers then. Preferred building my colour TV transmitters and other elctronic stuff as a radio ham. I could transmit colour TV 18 months before the official operation colour TV.

Barry

CraigS · #12 19-03-2011, 11:41 AM

I think mine ran at a princely clock speed of 1 MHz !!

It had a 16 bit address bus and an 8 bit data bus !

I think it originally became available in 1974.

It had a serial i/o port as I recall, also.

Can't remember how much RAM the kit had, but it was tiny compared with today's monsters !

I also think that Sinclair used it as the the basis for the Sinclair Mk14 (1977), which was the forerunner to Bart's ZX81 (1981).

I think the SC/MP's main competitor at the time was the mighty Motorola 6800 (1974).

Talk about a trip down memory lane, there Bart !

Thanks for the thread.

Cheers

Barrykgerdes · #13 19-03-2011, 12:20 PM

I think it had 1KB of static RAM but it might have been 1Kb. I ditched my scamp kit about 11 years ago when I moved.

Barry

CraigS · #14 19-03-2011, 12:25 PM

Quote:

Originally Posted by Barrykgerdes

I think it had 1KB of static RAM but it might have been 1Kb. I ditched my scamp kit about 11 years ago when I moved.

Barry

.. it seems hilarious, eh Barry ?

I don't think I could afford the extra chips and I do recall counting the memory in lots of 64 bytes !

How embarrassing !

Cheers

Bassnut (Fred) · #15 19-03-2011, 01:04 PM

What about the ZX80 that preceeded it?? I bought one as a kit from Boots in the UK in 79'. I still have the ZX80 and 81. The ZX80 was the revolution, a total of only 4 ICs !. I made 16k RAM expansion packs and A/D conversion PCBs for them in 81' (in OZ). Sold many of them, specially to universities. Some of the projects done by universities with the A/D convertors were amazing (as a data logging device), there was nothing else at the time, at the price that could do anything close.

dalemadison · #16 19-03-2011, 01:20 PM

I had one with the 8k memory module. I remember a couple of hours typing in a program from a mag and days debugging my typing mistakes.

CraigS · #17 19-03-2011, 01:22 PM

The Sinclairs were always more advanced than my puny, primitive Scamp.

The ZX 80 was terrrific ! (Wiki seems to think this was brought to market in 1980).

Get 'em mounted and framed, Fred !

I'm going to retrieve my Scamp, shortly.

All of these things should be regarded as world-wide treasures !

Ha !…

Quote:

Sales of the ZX80 reached about 50,000 — an unheard of number for the day which contributed significantly to the UK leading the world in home computer ownership through the 1980s. Owing to the unsophisticated design and the tendency for the units to overheat, surviving machines in good condition are quite uncommon and can fetch high prices by collectors.

Cheers

thunderchildobs · #18 19-03-2011, 01:50 PM

I sold my ZX81 +16K to upgrade to get my ZX Specturm, which I still have. I also still have the orginal ZX printer with a roll of silver paper.

Brendan

Bassnut (Fred) · #19 19-03-2011, 08:19 PM

Graig, yes this is such a nostalgia trip, got me digging the monster out, in perfect nick, and with original manual in tact !.

Your right, it was bought in 80' and it was the ZX81 that was 4 chip. The video out put handling was very clever I recall, used the dynamic RAM refresh function of the Z80 CPU to control the video raster display. My ZX81 had an extra IC stuck to the top of the CPU hand wired to the PCB to correct a firmware math bug.

The ZX thermal printer was a marvel too, so small and capable of amazing, chunky graphics.

There was a far more advanced computer PCB kit produced in North London at the same time as the ZX, at about the same price that I cant remember the name of at all and that I cant find any mention of anywhere now, but it didnt come with basic and was a ***** to program in assembler (I think it tanked as a result). I left it with a company in London I worked for at the time, and it became a prototype for automating studio sound mixing desks, the 1st in the industry.

The British are good at this sort of excentric, erratic out of left-field innovation, the TRS80 was boring in comparison.

Technically though, the US was far ahead, Ive worked on industrial machines that were built in 75' that were allready (discrete chip CPUs) 16bit albiet with magnetic core memory, you could actually see the individual bit cores on a giant PCB covered with a wired core array!. They are still in use to this day (Excellon XL3 PCB drill machines).

Thanks for the recall Bart !.

ballaratdragons (Ken) · #20 19-03-2011, 08:25 PM

Never seen one, never heard of them.

My 1st computer was a Commodore 64 and I didn't know how to use it.

Nothing's changed