How bad was the wobble on the zx81

General Chit Chat about Sinclair Computers and their Clones
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1024MAK
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Re: How bad was the wobble on the zx81

Post by 1024MAK » Wed Nov 07, 2018 11:44 pm

It should also be noted that the ribbon cable system for the ZX Spectrum did not work as well as you may have expected. After all, look at how many wires make up such a link, then consider that they are all glued together, hence they are rather stiff. So no real improvement...

What is actually needed, is a connector that is designed to be a proper mechanical linkage. Card edge-connectors are actually intended to just be used for electrical connections in a card frame system, where PCB runners and other mechanical fixings are used. In such a system, card edge-connectors are much more reliable.

Mark

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gammaray
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Re: How bad was the wobble on the zx81

Post by gammaray » Thu Nov 08, 2018 12:12 am

There was also a vaccu-formed plastic tray where the cables routed underneath and the tape deck, zed and rampack sat in pockets with a inclined plateau for the TV to sit on. *Perfectly fitted so nothing would move.

C
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM

brozier
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Re: How bad was the wobble on the zx81

Post by brozier » Thu Nov 08, 2018 2:00 pm

Crayon21 wrote:
Tue Nov 06, 2018 11:19 pm
I've heard a lot about the wobbling issue with the ZX81. how bad was it? did it really wipe out everything?
It was very frustrating, I made a little metal bracket that clamped the Sinclair Rampack to the main case - using the original screw holes. Helped a lot.... :D

Julia

Moggy
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Re: How bad was the wobble on the zx81

Post by Moggy » Thu Nov 08, 2018 6:49 pm

brozier wrote:
Thu Nov 08, 2018 2:00 pm
Crayon21 wrote:
Tue Nov 06, 2018 11:19 pm
I've heard a lot about the wobbling issue with the ZX81. how bad was it? did it really wipe out everything?
It was very frustrating, I made a little metal bracket that clamped the Sinclair Rampack to the main case - using the original screw holes. Helped a lot.... :D

Julia
Hells teeth! I have a ton of those little "L" shaped brackets how come I never thought of this!!?

DUH!! :oops: :oops:

swensont
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Re: How bad was the wobble on the zx81

Post by swensont » Sat Nov 17, 2018 1:18 am

I faced two issues when I got my ZX81 in Nov. of 81.

1. Kept over heating and crashing

I learn not to use the ZX81 on a shag carpet. Once I put it on a desk or such, it was fine.

2. Moving the ZX81 with the 16K pack would cause a crash

When the ZX81 was picked up, the 16K pack was not secure enough to not move. It moved slightly which caused the top edge connectors to disengage from the ZX81 external connector.

My solution was to use duct tape to tape the ZX81 and the memory to a small piece of peg board. Now that both were secured to the board, I could pick up the ZX81 with no issue. The ZX81 and memory did not move in relation to each other. It was a big ugly, but very effective.

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Ed in SoDak
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Re: How bad was the wobble on the zx81

Post by Ed in SoDak » Sun Jan 06, 2019 5:17 am

Most everyone enjoyed cussed at the same quirks. My first quick answer was to solder the outer RAMpack terminals to the TS1000 connector. Later, I solved the poor loading, heat, RAM wobble and keyboard problems with a little hacker upgrade. A surplus TI99 keyboard in an open bottom plywood case with soldered RAM and board mounted within and a recessed power switch plus loading meter on top.

The TI keyboard required a lot of cut traces and added wires to adapt it to the Timex, but everything else was pretty simple soldering of a few wires connecting the switch, power jack and meter. I'd program in FAST mode and could enter lines as quick as I could type. It would run for hours without a single crash, even when moving it around a lot. Its beauty was in function, not looks! :lol:
-Ed
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Crayon21
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Re: How bad was the wobble on the zx81

Post by Crayon21 » Sat Feb 16, 2019 12:22 am

I wonder why the Timex Sinclair 1000 failed in the U.S? what exactly happened for it to not have any market share?
zx81: great yet flawed
Zx spectrum: masterpiece that keeps on giving

(wish it weren't so expensive) :o

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gammaray
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Re: How bad was the wobble on the zx81

Post by gammaray » Sat Feb 16, 2019 1:30 am

My opinion, having owned one in 1982, was that:

If Timex had introduced only the Timex Sinclair 1500 first which had a "workable" keyboard, and 16K memory built onto board, it may have fared far better. People were so disappointed because of crashes and lack of keyboard that there was no word of mouth promotion.

I understand that the case design was sourced later from the Spectrum prototypes but this was no excuse for Sinclairing the American market. Remember the quality problems of other previous Sinclair products?

I think the speed of the US model was slower as well so game software is not as responsive.

I did not mind cassettes but I hated the wobbly rampack and the keyboard which was difficult to use. Pressing would cause the flexing which caused rampack to move and the subsequent crash.

Possibly the 1500 should have been sold with a cartridge adapter (built-in?) and one sample cassette and cartridge to promote simple operation but give the option of using a cassette.
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM

Kai
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Re: How bad was the wobble on the zx81

Post by Kai » Sun Feb 17, 2019 11:01 am

Lardo Boffin wrote:
Wed Nov 07, 2018 8:59 pm
Wow. I have absolutely no use whatsoever for a zeddy with 1MB of RAM but I really want one! :shock:
Go back to 1993. Since then we have 1 MB RAM for the ZX81:
http://www.fischerkai.de/zxteam/mega_e.htm
And with 628512 (512kx8) RAM chips on it you'll have 4 MB.
It is nice for fast animation with HRG screens and a diskcopy routine.

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mrtinb
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Re: How bad was the wobble on the zx81

Post by mrtinb » Sun Feb 17, 2019 11:17 am

The 512k on the ZXblast suits me fine. :)
Martin
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube

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