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ZX81, Anyone? — Parallax Forums

ZX81, Anyone?

PJAllenPJAllen BannedPosts: 5,065
edited 2011-03-13 12:23 in General Discussion
July 1982 ads.· This was cutting-edge stuff.· The keyboard was totally aggravating and kept it from gaining acceptance.
July82_zx81_1.jpg
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July82_zx81_2.jpg
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Comments

  • kwinnkwinn Posts: 8,697
    edited 2010-03-22 03:24
    Ah the good old days. By the time I retired my first S100 system I had spent over $7000.00 on it and the only item that was used on the PC clone that replaced it was the printer. Just think what we could get for that amount today.
  • bill190bill190 Posts: 769
    edited 2010-03-22 05:31
    My first "computer" about that time was a Bally Astrocade with the Basic cartridge and an interface to a cassette player.

    You would record your programs onto a cassette. Or play to load the program into the system.

    All programming was done·via a keypad with about the same number of buttons as a phone. Looked like this...

    http://alteeve.com/~lance/bally/bb_ovrl2.gif

    Bally Astrocade...

    http://www.huguesjohnson.com/features/mgc2007/astrocade.jpg

    Basic cartridge and cassette adapter...

    http://www.computercloset.org/BallyArcadeBASIC.jpg

    (You provided the cassette tape player.)
  • LeonLeon Posts: 7,620
    edited 2010-03-22 08:28
    This was my first computer:

    www.computermuseumgroningen.nl/motorola/mek6800d2.html

    It cost me £209, which was quite a lot of money back in 1976. It came as a kit, and involved a lot of soldering.

    128 bytes of user RAM was provided, I added another chip giving me a massive 256 bytes! Code had to be written in assembler on paper and hand-assembled. and I got quite good at it, helped by a little program I wrote that calculated the offsets for relative branches. I even wrote a simple game for it. Some people expanded them into full-blown computers by adding external memory, video, floppy disk controllers, and so on. I just bought a TRS-80 Model I as soon as they were available in the UK.

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    Leon Heller
    Amateur radio callsign: G1HSM

    Post Edited (Leon) : 3/22/2010 8:43:56 AM GMT
  • skylightskylight Posts: 1,915
    edited 2010-03-22 11:55
    The great thing about the zx81's rampack was the design flaw that eventually caused a hairline crack in the plastic of the connector and certain keystrokes reset the computer which was great when you were a couple of lines of code away from completing a 100+ line programme of typing!

    built the zx80 in kitform also, loved the plastic rivets that joined the casing together.

    for all their faults the programmers still managed to fit games like chess into 1k of memory because they had to and didnt have the luxury of masses of ram that the lazy programmers of today insist on.
  • stamptrolstamptrol Posts: 1,731
    edited 2010-03-22 12:58
    As the first home computer under $200, there are many ZX81's and Timex/Sinclairs still hidden away in basements everywhere.

    One of my first industrial projects was an automated cable assembly tester for the military. It was based on the ZX81 and its less-than-perfect expansion port plugged into a massive, hand wired relay board made with reed relays. It worked like a charm and provided a tracking document to show the results of the automated wire-to-wire-to-ground conductivity and hi-pot tests. Other than having to lug a CRT display around, it was nicely portable and could go onboard the ships to test the cables after pulling which was where most damage was done.

    When the Tandy 100 pre-laptop came out with an accessible interface port, it was an amazing step forward.

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    Tom Sisk

    http://www.siskconsult.com
    ·
  • sylvie369sylvie369 Posts: 1,622
    edited 2010-03-22 16:19
    stamptrol said...
    As the first home computer under $200, there are many ZX81's and Timex/Sinclairs still hidden away in basements everywhere.
    Indeed - here's mine, dusty but still in good shape, with the memory pack and an experimenter's board.
    zx-81 small.jpg
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  • wjsteelewjsteele Posts: 697
    edited 2010-03-22 19:01
    My fist computer was a ZX80 kit. My second... a ZX81 Kit. My third... a Timex Sinclair 1000... with a whopping 2K of ram!!! After that, things went downhill from there.

    BTW... every single computer I have ever owned is in my basement still in working condition! I had to repair the ZX81, but it still works. I still have two ZX81 kits unopened... someday, I'll put one of them together for fun.

    Bill
  • ercoerco Posts: 20,257
    edited 2010-03-22 20:02
    I love my·old Timex Sinclair and subsequent Commodore 64 computers! Great first computers. ·I'm saving them for "something good"... I was about to use my Timex for the first Firefighting Robot contest in 1994 when I saw the BASIC Stamp 1 in N&V. The rest is history.

    Neat Sinclair emulator at http://www.vavasour.ca/jeff/ts1000/

    My Dad built an Imsai 8080 (the Poor Cousin (?) of the Altair 8080) made famous in "War Games". My brother and I were underwhelmed at the toggle switch user interface, and we nicknamed it the "Clumsai". But I inherited·Dad's·love of gizmos, and someday I'll inherit·his Imsai·to add to my collection. http://www.imsai.net/

    lobby_card.jpg


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    ·"If you build it, they will come."
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2010-03-22 22:23
    oh wow...nostalgia trip...thanks PJ...now where did I hide those Z80 CPU chips?

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    Chris Savage

    Parallax Engineering
    ·
  • icepuckicepuck Posts: 466
    edited 2010-03-22 23:28
    I still have my Sinclair with the massive 16k ram expansion.
    -dan

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    Arguing with myself--sometimes me, myself, and I don't always agree.
    (Former) Caterpillar product support technician
  • ercoerco Posts: 20,257
    edited 2010-03-23 04:36
    Speaking of vintage "computers", I also have a 1960's-era Friden STW-10 mechanical calculator.·Very advanced for its day, these were heavily used in aerospace. Check out·this 42-pound electric typewriter-sized beast:

    ·http://www.oldcalculatormuseum.com/fridenstw.html·and someone's video at http://www.youtube.com/watch?v=w4pdYYv33QI

    stwmult.jpg·stwleft.jpgfridenstw.jpg


    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ·"If you build it, they will come."

    Post Edited (erco) : 3/23/2010 4:41:15 AM GMT
  • skylightskylight Posts: 1,915
    edited 2010-03-23 18:01
    On the subject of mechanical calculators, the elegant very expensive(today) curta handheld is a beaut, wish i could afford one.

    Curta-506677-1-267x415.png


    www.vcalc.net/cu.htm
  • LeonLeon Posts: 7,620
    edited 2010-03-23 18:46
    When I started working for Rank-Xerox (UK) in 1966, our accountant used one of these:

    www.vintagecalculators.com/html/facit_c1-13___esa-01.html

    My brother ordered it when he worked there previously.

    They then got one of the first electronic desk calculators, it was very expensive. I was playing with it one lunchtime and found that if I held some keys down while it was switched on, the displays went bananas, and the keys wouldn't do anything. I left it like that and the girl who had been using it got very worried when she got back after lunch, she thought she had broken it.

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    Leon Heller
    Amateur radio callsign: G1HSM

    Post Edited (Leon) : 3/23/2010 6:52:24 PM GMT
  • skylightskylight Posts: 1,915
    edited 2010-03-23 19:00
    the sinclair cambridge used to scroll the digits fast trying to count to infinity if you inputted 1/0 more fun than the error message you get these days

    And how many looked in awe at the discovery of "shelloil"( 71077345 ) for the first time when someone turned their calculator upside down?

    Post Edited (skylight) : 3/23/2010 10:33:32 PM GMT
  • mparkmpark Posts: 1,305
    edited 2010-03-23 19:47
    5318008
  • skylightskylight Posts: 1,915
    edited 2010-03-23 22:32
    nono.giftongue.gif

    More fun

    www.langmaker.com/calculatorwords.htm
  • LeonLeon Posts: 7,620
    edited 2010-03-24 06:01
    I had some fun with Wordstar where I worked once. I read somewhere that you could get some amusing suggestions if you typed peoples' names and ran the spell-checker, so I typed in the names of everyone in our group. Our (universally disliked) manager's name resulted in "colostomy" and someone else's as "spanker". We referred to them as Roy Colostomy and Dan Spanker from then on.

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    Leon Heller
    Amateur radio callsign: G1HSM

    Post Edited (Leon) : 3/24/2010 6:08:44 AM GMT
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2010-03-24 13:10
    We·began with a gentle reminisce and here it's carommed off into the unseemly.· O!, Perfidious Albion.· smile.gif
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2010-03-24 15:00
    PJ, you're surprised?

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    Chris Savage

    Parallax Engineering
    ·
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-03-12 18:56
    It was 30 years ago today,
    That the geeky all began to play,...

    http://www.bbc.co.uk/news/magazine-12703674
  • blittledblittled Posts: 681
    edited 2011-03-12 19:12
    My first computer was a Timex Sinclair 1000 my mom bought at a local grocery store's promotion. I got it during college while I was learning 6502 assembly since Penn State thought the 6502 was the cpu of tomorrow. I learned a lot more about assembly from playing with the TS1000. The only thing I hate about it is the membrane keyboard connections get brittle over time and crack causing the keyboard to fail. I have about 16 Z80A chips laying around and was toying with the idea of connecting one to a Propeller.
  • Martin_HMartin_H Posts: 4,051
    edited 2011-03-12 19:56
    My first computer was an Atari 400 which was 6502 based. I became proficient at 6502 assembler and actually started to like it. Years later I learned that the 6502 was called the Turing tar-pit because of its minimalist instruction set.
  • BeanBean Posts: 8,129
    edited 2011-03-12 19:57
    The Timex Sinclair 1000 was my first computer. My family was quite poor at the time, so it was quite an investment for them.
    The thing ran so hot it would shut-off after about 20 minutes. I took to putting an ice pack under it so I could use it for longer periods.
    My best friend got a CoCo. We would spend hours writing games for each of our machines.
    The TS1000 was SO slow it wasn't even funny. Then I discovered machine language and my life was never the same.
    I remember writing pages and pages of hex codes for games, hand calculating relative jumps because I would only input hex codes into the TS1000 (didn't have an assembler).
    I got the 16K ram pack by working in a local store and saving for it.
    The keyboard was terrible but I have very fond memories of that TS1000. I bought a couple on ebay, but they never seem to work. Usually the keyboards are defective.

    Bean
  • wrightmewrightme Posts: 43
    edited 2011-03-12 20:18
    I still have a ZX-81 somewhere. The membrane keyboard bit it.

    I ordered a 1k kit in 82, and those were out of stock, so they sent me a 2k assembled one instead.
  • kwinnkwinn Posts: 8,697
    edited 2011-03-12 20:23
    Since I listed my first computer near the beginning of this thread I will not do so again. I will celebrate the occasion by getting a glass of sherry for a toast.
  • LeonLeon Posts: 7,620
    edited 2011-03-13 01:14
    Here is an interesting BBC article on the ZX81:

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

    I bought one out of curiosity, although I had a much more capable machine. I gave it to my brother's sons, and one of them (about 10 at the time) subsequently made a career in IT.
  • HumanoidoHumanoido Posts: 5,770
    edited 2011-03-13 03:01
    This is very interesting! I bought around 50 TS1000's and used the boards
    in a big machine and a robot. That was my first very powerful multi-processor
    machine. It did vision, speech recognition, speech synthesis, some AI, and
    had extra RAM & I/O boards for control. Full size keyboards were built
    and interfaced. The machine ran several programming languages
    like Forth, BASIC, Logo, etc. It was my 1st multiple language
    platform. It ran from this crazy video modulator circuit with all the interference
    lines until I did a direct video mod for NTSC video which was clear and sharp.
  • Peter KG6LSEPeter KG6LSE Posts: 1,383
    edited 2011-03-13 03:57
    My dad had a old AT 286 and I had a apple 2GS then a mac SE . MAN os6 was HOT STUFF . and GUI . .............the world is now never the same ...

    I still have that old SE , and besieds NASTY screen burn its still a working computer .

    and I added a Ethernet card to it 4 Y ago . It WILL do the web . !!!!!!!!!
    It makes me cry to think how fast we dump our digital friends each year for a new modle

    in 90 or so my dad got a PS2 and a mac performa 6214cd with a WHOPPING 1.2 gb HD . I uset to play widget workshop for hours . ( think of a kids version of electroncs workbench ) it had gates !! AND OR NOR ext so it was a VERY usefull tool to Get me in to electronics .

    still have the HD from it . and it boots ! .

    then in the 99 I got a PC a AMD k62 with 3d now . 450 I bumped to 500 MHz ( Jumpers FTW ! ) 7.2 GBb HD and win 98SE . I liked it , and it was never online so it never had the virus issue so it was a good system . and it morphrd many times in to a athlon 700 and a bigger case with 3 CD drivres so I could play a CD audio while playing a2 disc flight game ....

    then I got a 450MHz Imac DV SE with a 20G HD and a 512 ram . on OS9 that thing was cooking with gas ! I got obsessed with Imovie ( i think everyone was at the time ) and I slowly got away from Win PCs and have never looked back.

    now I run a server 2 laptops and a mac mini . still some days I wish I was 16 again with my crummy flight sim and my huge 14" CRT ( ROLLS EYES) and not have this easy stuff'

    I made every IDE cable I used . I got ends and cable .and took Pride in making the cable just the right size . and over clocking by 50MHZ was unherd of .

    I would say us who HAD to know what a IRQ was or a EDO ram was . . thease new geeks they plug and play .. WE pluged and prayed ./

    I still have taht AMD and its in Ok shape . but the HD is not in good shape . ..I kinda miss sim city 2000 right about now .

    I may have to emulate . any modern computer has plenty of overhead to run old SW in a VR .

    and the mini is X86 so one ov thease days .


    heheh 98SE on a core I7 LOLS LOLS 2GB ram and a SSD I kinda want to see it run just for the heck of it .
  • w4fejw4fej Posts: 264
    edited 2011-03-13 05:34
    erco wrote: »
    I love my·old Timex Sinclair and subsequent Commodore 64 computers! Great first computers. ·I'm saving them for "something good"... I was about to use my Timex for the first Firefighting Robot contest in 1994 when I saw the BASIC Stamp 1 in N&V. The rest is history.

    Neat Sinclair emulator at http://www.vavasour.ca/jeff/ts1000/

    My Dad built an Imsai 8080 (the Poor Cousin (?) of the Altair 8080) made famous in "War Games". My brother and I were underwhelmed at the toggle switch user interface, and we nicknamed it the "Clumsai". But I inherited·Dad's·love of gizmos, and someday I'll inherit·his Imsai·to add to my collection. http://www.imsai.net/

    lobby_card.jpg


    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ·"If you build it, they will come."

    "My Dad built an Imsai 8080 (the Poor Cousin (?) of the Altair 8080)"

    I purchased IMSAI serial number lucky #00013. It was before the Altair box. I had the switches set up as octal and got to be very adept at programming via the switches. Also learned the HARD way to check and double check the correct values in every memory location before hitting the execute button less we had to start all over again!! lol. I finally got two 8 inch disk drives and all 64K (yes "K", not megs!) installed. Copying between the two disk drives would have made a pile driver proud! The IMSAI 8080 when fully populated doubled nicely as a really good room heater!! The memory drew so much current that we had to add buss wire to the plus 5 volts and ground to help reduce the current spikes!!

    Wish I still had the box as they are now selling for north of $3,000.00 in the collectors market!!

    My first "attempt" at a computer was with a GodBout (Oakland Bay California surplus electronics store) 4004 that they generously called a "kit". Never got anywhere with that though...

    (Geez, I woke up and discovered I was old!!)

    MIke B.
  • w4fejw4fej Posts: 264
    edited 2011-03-13 05:44
    erco wrote: »
    Speaking of vintage "computers", I also have a 1960's-era Friden STW-10 mechanical calculator.·Very advanced for its day, these were heavily used in aerospace. Check out·this 42-pound electric typewriter-sized beast:

    ·http://www.oldcalculatormuseum.com/fridenstw.html·and someone's video at http://www.youtube.com/watch?v=w4pdYYv33QI

    stwmult.jpg·stwleft.jpgfridenstw.jpg


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    ·"If you build it, they will come."

    Post Edited (erco) : 3/23/2010 4:41:15 AM GMT

    Oh yea!. I think I saw one of those in action a hundred years ago!! Didn't the top portion move left and right ala typwriter style for larger numbers?? In the 60's my God Father had a mechanical calculator repair business in San Jose. He started his company just about the time the first handheld calcs came out. (great timming dude!) He went out of business shortly there after!! lol.

    Mike B.
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