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Timex Sinclair ZX81 Back On the Market
Eugene Blanchard writes: "You still have the chance to purchase that Timex Sinclair ZX81 computer. Someone has kept a warehouse full of them. I had a few and thought that they would make a pretty good controller board with the Z80 processor. Now let's see if we can load Linux on them! "
Imagine a beowulf cluster of these things! ;)
Heres a link to a page with details for building your own ZX80/ZX81 from scratch:h tml
http://www.home-micros.freeserve.co.uk/zx80/zx80.
$100! Now that's inflation.
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uhm, will they sell me a 70's era tv that has UHF channels still on the "dial"?
I started off with the trs-80 model 1, so while I'd like to own one of these for memory's sake [sic], there's no friggin way I'm paying a c-note for a chip that can't even be given away (the z80).
and I bet you'd have to take steel wool to the pcboard since its probably tarnished beyond all believe from oxidation.
--
--
"It is now safe to switch off your computer."
The easy BASIC of the TI99/4a got me into computers. You could do text to speech with the speech synth and the Terminal Emulator 2 cartrage. You went into "BASIC" (which the TE2 cart modified in some way) and do something like the following:
:)
10 open #1,(some link to the speech synth, forgot what it was)
20 print #1,"Hello! blah blah blah"
How more easy can you get? you could modify the speech by doing something like this (not sure of the syntax):
30 print #1,"\\50 40"
The first was the pitch, and the second was the rate the tone would drop as it spoke. You out really high/low values and get crazy disorted voices out of it. Good for making prank phone calls.
I even had the PE box (extra 32k,disk drive,rs-232,cool blinking lights), but the stupid extra thick cable always kept falling out of the bus port. The Extended basic cart let you do hardware based sprites, which looked way cooler than moving a character block by block.
Games? Parsec, of course. Remember trying to re-fuel by hitting '3' and steering in the narrow tunnel? Had most of the Atarisoft games, Tunnels of Doom, some infocom games (HHGG, still have the "Don't Panic" button), and other stuff. I used TI-Writer to do all my high school papers, and had to send escape codes directly to the printer to do underlining (good thing TI-Writer supported that trick). Even had TI-LOGO, that let me play with simple recursion. Of course, by the time I got all this stuff, it was dirt cheap.
Now let's see if we can load linux on them!
Ugh, must EVERY story mention Linux? I mean, I know we like Linux and everything, but mentioning putting it on a 4.77MHz Z80 just makes me feel sick.
What would be an otherwise excellent nerdy retrocomputing story is tarnished by the ObLinux mention. Can't people just appreciate this stuff for what it is?
I'll say it again, ugh.
Quidquid latine dictum sit, altum viditur.
Just remember how little you can squeeze in there. Your program and data have to fit in 1024 bytes... unless you get the memory pack.
A PC 80x25 character screen is 2000 characters.
I bought one of these at a garage sale for $15CDN when I was in gradeschool. It was so cool.
I think that exhausts all I have to say about the machine.
"Anybody who pays $99.95 for these is -- excuse me -- a fucking moron."
:)
If it wasn't for morons, Ebay would not exist.
Thank god for Goodwill and Value Village, it's where I get most of my clothes. Got a SGI/Cray T-shirt there for $1.00.
And now, as a service to the Bored Slashdot Reader...
The best thing to do at a Goodwill is this:
1. go to a goodwill
2. look for some used answering machines
3. take the tapes out
4. take them to the checkout, the chasier will just make up some price
5. most people NEVER erase the tape before giving it to goodwill, so now you can go home and listen to peoples messages.
It's alot more fun than it sounds. Sometimes you get some downright surreal stuff. Sometimes you get a whole conversation, because the machine didn't stop recording when someone picked up the phone. I have one where some old guy is talking to his buddy about how his wife and her friends are eating all the damn food. The next message was from his doctor about his colon operation apointment. Nutty, Man....
The TI-83, the most popular one, retails for about $100, but is smaller, uses only 4 AAA batteries, has a serial port, and can be carried around in a pocket to show off your geekiness. Still, you could use the Sinclair ZX81 as sort of a base station, or one with an AC adapter and TV out. But never underestimate the utility of a programmable Z80 graphing calculator.
Tell me what makes you so afraid
Of all those people you say you hate
Oh man, that's UPN where I live. There goes Moesha...
-josh
I remember ordering and building my Sinclair back before Timex became involved and it became the ZX81. Wow, what a memory trip it is to think about putting together that thing... I can almost smell the 60/40 now.
Unfortunately, I never got to do much programming on mine... it had a temperature problem. After a few minutes of running, the TV would lose horizontal sync. Turned out that my ROM chip ran way too hot, and as it warmed up the TV signal went out of sync. Sinclair must have saved money on components by interleaving the sync of the ROM with the video generator, instead of having separate clocks for each. My girlfriend's techhead brother figured this out for me -- never would have discovered it on my own.
We solved the problem by keeping a piece of ice on the ROM chip, in a little plastic bag. Every so often, when the ice had melted, I'd have change the bag for one with a fresh piece of ice. Talk about your cooling problems -- and I wasn't even overclocking!
--Jim
a lot of folks are going to wax nostalgic over this here machine, but I'm gonna have to disagree. This was my first computer. I recieved it IIRC around Oct 1982, and I was stunned at how crappy a machine this was. I was 9-10 years old, personal computers were an utterly and completely brand new phenomenon, but I could immediately sense the uselessness and cheapness of this machine.
My dad, who bought it for me, had previously engineered some of the first networked cash register systems in the mid 70's (for the Burger Chef chain of fast food resturants), he was/is a primordial hax0r, but even he couldn't get into this dog. But he could understand my dismay, so he got me a TI994a.
I would love to get a bevvy of brand new TI99 parts, maybe even c64 or some '086's, but I can't quite bring myself to embrace this amazing find.
just my $.0200251
:)Fudboy
:)Fudboy
I guess I'm only a Fudboy, looking for that real Transmeta
This chip is a definite classic. Has any instruction set been in use as long? Indeed, before IBM jumped into the microcomputer market, Z80-based systems were the standard for desktop business computing. And probably the most popular config was an Apple ][ with a Z80 coprocessor board. (I once nearly bought the Microsoft version of this one!) If Apple had known how to exploit its dominance in this market, history would be very different.
I just went to the Zilog web site to see what they were up to, and found the latest Z80 product: an embedded web server!
__________
I've just installed linux on my bodylotion box and I am creaming it all over my body.
I had a few and thought that they would make a pretty good controller board with the Z80 processor.
I did a project in high school (~1985) trying to use a ZX81 as a controller for a robot. It worked, kinda. Very susceptible to emi, especially the sort that small DC motors put off. It used technology that was "good" for the time, which translated to today's technology, means "slow and power hungry."
Other than the "vintage-cool" factor, as a controller, you can do a whole lot more with a modern microcontroller. More I/O, similar amount of memory, much more in terms of MIPS/W. You do lose the video display and the ability to program it in BASIC.
The ZX81 was a great hack. The ability to implement a GUI (it did output to a TV) and an interpreter with that little amount of processing horsepower, RAM and ROM is a pretty impressive feat, especially keeping it relatively cheap.
I think that we could all learn something from the ZX81- it is amazing how far you can stretch your resources when you don't have many. The real power of such knowledge is knowing when it is appropriate to use it.
- BASIC in an 8KB ROM.
- 2KB RAM on board
- Expandable to 16KB RAM with a "backpack"
- Expandable to 54KB RAM max with some mods.
- A 40 key keyboard with multiple shift modes to get all of the characters and BASIC keywords.
- Cassette interface for program loading and storing.
- A low cost thermal printer.
This was not a serious machine; it had major shortcomings. But the price was right.The keyboards were very troublesome. The thin ribbon connector often cracked from the heat and aging, disabling the membrane keyboard. With a little experimentation you could still "pick" it with wire ties. ;-)
The cassette interface was flakey too. They recommended a mono portable cassette recorder, run from batteries. The volume level had to be "just right."
The memory backpack was troublesome as well - it wiggled too much, breaking the connection to the card edge connector on the back of the machine.
Entering programs on this machine was truly unique - you didn't type the word "PRINT". You pressed "P", and depending on where you were on the line, the BASIC interpreter knew if you were going to enter a keyword ("PRINT"), or if you wanted the letter "P". Sorry, uppercase only.
It was amazing was assembly language programmers could do with this thing. I fondly remember the Flight Simulator, which fit on a 16KB machine. There were programmers toolkits on cassette, and other little applications. Data storage was a serious problem though.
Is there an archive of ZX81 software anywhere, possibly in WAV or MP3 format? I still have my cassettes, but after 16 years of disuse I doubt that they are readable.
Mike
PS: Search on google - there are several projects out there for emulators.