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Re: Improving Timex/Sinclair Tape Loading
Posted: Wed Oct 25, 2017 11:04 am
by sirmorris
OK, ok. Let's make this a community effort. I can't do it by myself.
Things to do: (
= DONE)
1. Design PCB
* transcribe schematic into a CAD package
* lay out a board
* do
* make countless tiny alterations to board
* until happy
2. Make a protoype board
* identify components
* adjust layout according to available parts
* optional: return to step 1 to update board
* if a trivial change then skip this step after changes
3. Send board for manufacture
* if count < 10
* use Seeed fusion prototype service
* else
* find another supplier
4. Assemble parts inventory for kits.
5. Make kits.
6. Sell kits.
I am most of the way through part 2. As Lardo B. has parts on order I'll send him a home-made board for stage 2 protoyping. If it works I'll progress stage 3. I may want some cash up front if not using Seeed.
I'll be honest with you, I don't want to do 4, 5 or 6. Also I wouldn't expect anyone to have to do this without $£$ input, so we'll have to come up with a plan to make this happen. This will perhaps work in conjunction with step 6.
Anyone on board? (no pun intended)
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Re: Improving Timex/Sinclair Tape Loading
Posted: Wed Oct 25, 2017 11:05 am
by siggi
gammaray wrote: ↑Wed Oct 25, 2017 3:15 am
But do we have to use batteries... then the power jack "should" be different and an option.
I think that batteries are the best solution!
The circuit needs a bipolar power supply ( + and - voltage!), thus an external power supply must have + and - and GND as output or must have an AC output, which could be rectified to + and - inside the box. But then a lot of filtering would be necessary to get such a smooth voltage like coming from the batteries ...
Siggi
Re: Improving Timex/Sinclair Tape Loading
Posted: Wed Oct 25, 2017 11:24 am
by sirmorris
Points for discussion:
1 / ?
* Should the PCB be sized for a case/enclosure of some sort? If so, which? It's no use specifying a Maplin (UK electronics shop) part if our US friends are to try and find one. I think a box with a PCB holder/slot and room for batteries would be good. I could add a front panel to the PCB layout.
Re: Improving Timex/Sinclair Tape Loading
Posted: Wed Oct 25, 2017 11:56 am
by Lardo Boffin
I’m on board. I don’t have a great deal of expertise to add to the mix (having reignited the whole thing
) but am happy to have a go at assembling one. I still need a couple of bits such as a case and cables (and batteries!) but they are easy enough to get.
I would see if there is a case size that is available both sides of the pond and settle on that. Or one that is very close!
I definitely think this is worth pursuing - if it works as indicated it could save a lot of tape based loading stress. I have a carrier bag full of cassettes (nearly) that won’t load and this may help with that.
Re: Improving Timex/Sinclair Tape Loading
Posted: Wed Oct 25, 2017 1:51 pm
by Paul
OK. Now I am in.
Charlie, could you please change the footprints for input slave and output to use the standard ZX80/81 connector? And a few holes for screws?
I will make a 3D Printed case and offer Pcbs and ready built devices for sale. I don't indend to offer kits. Too much work.
Kind regards Paul
Re: Improving Timex/Sinclair Tape Loading
Posted: Wed Oct 25, 2017 1:53 pm
by sirmorris
OK. That makes sense for the production boards. I'll add mounting holes on a .1" grid. Or do you prefer metric, Paul?
Lardo: If you have a BOM from your order could you supply (email/pm) me with it so I can cross-check component sizes with the layout? I'll make a home-made PCB and send it to you when I've adjusted for the actual components that you have.
Re: Improving Timex/Sinclair Tape Loading
Posted: Wed Oct 25, 2017 3:37 pm
by Paul
Inches are fine with me.
Re: Improving Timex/Sinclair Tape Loading
Posted: Wed Oct 25, 2017 3:49 pm
by Lardo Boffin
sirmorris wrote: ↑Wed Oct 25, 2017 1:53 pm
OK. That makes sense for the production boards. I'll add mounting holes on a .1" grid. Or do you prefer metric, Paul?
Lardo: If you have a BOM from your order could you supply (email/pm) me with it so I can cross-check component sizes with the layout? I'll make a home-made PCB and send it to you when I've adjusted for the actual components that you have.
I will send what I have later on.
Re: Improving Timex/Sinclair Tape Loading
Posted: Thu Oct 26, 2017 2:07 am
by Dim_75
Hi all,
On my side I wasn' t able to make a good PCB, i still stuck on schematic transcription issues so i am happy that sirmorris did it succesfully !
(i really need to find some documentation like "PCB Design for Dummies" ...
)
I like the remarks from gammaray about the plugs for IN/OUT, if easy to do.
Thank to the 'PRO' (Paul, sirmorris...) giving a boost on this usefull project
Re: Improving Timex/Sinclair Tape Loading
Posted: Thu Oct 26, 2017 10:00 am
by sirmorris
CAD is something of a black art - there are very few tutorials. I have been working with Eagle since 2008 and I still have to find help sometimes
Don't be disheartened - keep at it! It's a very useful skill.
C