Sinclair ZX80 / ZX81 / Z88 Forums

Once this works, we should have a list and file share of all the tapes we rescued using it.

Ok maybe I should contribute and make the kits. If given a parts list I can order and bag the kits? From the U.S.?

Just wanting to keep the ball rolling here,...

gammaray wrote: ↑Thu Oct 26, 2017 5:00 pm If given a parts list I can order and bag the kits?

There is a parts list in the original article .pdf file.

How "complete" would we want the kits to be? In my own case, I have things like resistors, battery holders, and switches already in my junk box, so I don't know if I'd want a kit or just the circuit board to populate myself.

From just a quick look on eBay.ca, the monolithic caps (4 identical) can be had from China at 100 units for an American dollar. The ICs are similarly 10 for a dollar. 4148 diodes are of course ubiquitous and cheap. The 100PF silver mica capacitors are a little more dear at unit prices, but cheaper in quantity.

For someone (gammaray?) to effectively price the parts for complete kits, he'd have to have a rough idea of how many units we are expecting to want. I've heard commitments for maybe 10. Am I too low? Opinions?

Another small side point if I may on the connectors. I had suggested the possibility of female sockets so one could use their existing double male cables if one wished. I sort of take it back--in my opinion it's better to avoid multiple connection points whenever possible.

I would order two 3' double-male cables from eBay for about $3 each, cut them in half, and solder them to the circuit board to keep make/break connections to a minimum. The Scrubber-Dubber would then plug directly into the two tape machines and ZX81.

Then again, I'm so paranoid of the brutally cheap sockets on the ZX81/TS1000 that I've done the same thing to virtually all my motherboards to start with. My Zeddys are octopuses. That's why my Scrubber-Dubber's ZX81 line terminates with a female connector.

gammaray wrote: ↑Thu Oct 26, 2017 5:00 pm Once this works, we should have a list and file share of all the tapes we rescued using it.

Absolutely!

Personal preference but maybe the board could be laid out for EITHER the pigtail or a female socket? Let the assembler decide?

Hmmm?

Charles

Once the female sockets are on the PCB there is no one keeping you from soldering wires there instead.
So your feature will be there automatically.

Maybe I misunderstood the direction the design was taking... I'll sit back on my couch now and wait for another opportunity to embarrass myself.

Once the female sockets are on the PCB there is no one keeping you from soldering wires there instead.
So your feature will be there automatically.

Could the following have something to do with it? I downloaded and took a look. I am a KICAD novice too.

Dim_75 wrote: ↑Mon Oct 09, 2017 2:11 am Well i tryed to make something with KiCad as my try with Eagle was not productive.

After some hours i was able to do the schematic as it seems to be necessery before makink any drawing of the pcb, but... it still have some errors when i try to validate the schematics.
Here i still have 3 errors (the green arrows) :
3 Debugging errors.JPG

I put the KiCad projet files in the zip :ZX-CleanLoad.zip

As it is the first time i use this kind of programm i may have forget something or misunderstood the manual.
Any of you familiar with KiCad can have a look ?

On the other hand IC1C looks superfluous? I have not researched the circuit thoroughly. Is it suppose to be a unity follower or buffer?

For you KICAD users, is the following layout correct?

Did we need to send money or be patient or take some helpful action?

Patience would be appreciated

But in the meantime, here are the eagle files I've worked on so far, also the schematic in pdf format if people want to check it against the original in the magazine.

Not my finest hour but I think it will work as a proof of concept. This is now trimmed, drilled and on its way to a certain Boffin.
I had some issues with my laminator, it was sticking, and consequently I've got a couple of broken traces but these have been highlighted and are easy to fix in the soldering.

If this works it's a trivial step into ordering boards. I won't be making any myself but I'm happy to shepherd the board house process if that would help people.

Excellent! Having had some experience of fixing tracks I have broken ( ) I suspect it will be no problem to sort.