Improving Timex/Sinclair Tape Loading

Discussions about Sinclair ZX80 and ZX81 Hardware
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sirmorris
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Location: oxon, uk

Re: Improving Timex/Sinclair Tape Loading

Post by sirmorris » Wed Oct 25, 2017 10:04 am

OK, ok. Let's make this a community effort. I can't do it by myself.

Things to do: ( :mrgreen: = DONE)

1. Design PCB
* transcribe schematic into a CAD package :mrgreen:
* lay out a board :mrgreen:
* do
* make countless tiny alterations to board :mrgreen: :mrgreen: :mrgreen:
* 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)
scrubber.png
scrubber.png (9.1 KiB) Viewed 125 times
--=== ZXpand+ ... A more moderner all-in-one upgrade solution for ZX81 ===--
* SD/MMC storage * 32K Hires-capable RAM * AY sound chip * Joystick port * Serial *
* BASIC enhancements - plug & play * Reset button * Auto-boot facility *

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siggi
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Re: Improving Timex/Sinclair Tape Loading

Post by siggi » Wed Oct 25, 2017 10:05 am

gammaray wrote:
Wed Oct 25, 2017 2:15 am
But do we have to use batteries... then the power jack "should" be different and an option. :twisted:
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
My ZX81 web-server: online since 2007
http://zx81-siggi.endoftheinternet.org/index.html

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sirmorris
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Re: Improving Timex/Sinclair Tape Loading

Post by sirmorris » Wed Oct 25, 2017 10:24 am

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.
--=== ZXpand+ ... A more moderner all-in-one upgrade solution for ZX81 ===--
* SD/MMC storage * 32K Hires-capable RAM * AY sound chip * Joystick port * Serial *
* BASIC enhancements - plug & play * Reset button * Auto-boot facility *

Lardo Boffin
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Joined: Sat Nov 26, 2016 1:42 am

Re: Improving Timex/Sinclair Tape Loading

Post by Lardo Boffin » Wed Oct 25, 2017 10:56 am

I’m on board. I don’t have a great deal of expertise to add to the mix (having reignited the whole thing :oops: ) 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.
ZX81 iss 1 (bugged ROM, kludge fix, normal, kit)
Iss 3 with ZXVid, another in nearly perfect box
TS 1000 iss 3, ZXPand AY, ZX8-CCB & ZX-KDLX
TS 1500
TS 2000
Spectrum 16k (iss 1 s/n 1499)
Spectrum 48k
Toastrack + DIVMMC future

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Paul
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Re: Improving Timex/Sinclair Tape Loading

Post by Paul » Wed Oct 25, 2017 12:51 pm

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
In theory, there is no difference between theory and practice. But, in practice, there is.

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sirmorris
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Location: oxon, uk

Re: Improving Timex/Sinclair Tape Loading

Post by sirmorris » Wed Oct 25, 2017 12:53 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.
--=== ZXpand+ ... A more moderner all-in-one upgrade solution for ZX81 ===--
* SD/MMC storage * 32K Hires-capable RAM * AY sound chip * Joystick port * Serial *
* BASIC enhancements - plug & play * Reset button * Auto-boot facility *

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Paul
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Joined: Thu May 27, 2010 7:15 am
Location: Germanys west end

Re: Improving Timex/Sinclair Tape Loading

Post by Paul » Wed Oct 25, 2017 2:37 pm

Inches are fine with me.
In theory, there is no difference between theory and practice. But, in practice, there is.

Lardo Boffin
Posts: 623
Joined: Sat Nov 26, 2016 1:42 am

Re: Improving Timex/Sinclair Tape Loading

Post by Lardo Boffin » Wed Oct 25, 2017 2:49 pm

sirmorris wrote:
Wed Oct 25, 2017 12:53 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.
ZX81 iss 1 (bugged ROM, kludge fix, normal, kit)
Iss 3 with ZXVid, another in nearly perfect box
TS 1000 iss 3, ZXPand AY, ZX8-CCB & ZX-KDLX
TS 1500
TS 2000
Spectrum 16k (iss 1 s/n 1499)
Spectrum 48k
Toastrack + DIVMMC future

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Dim_75
Posts: 16
Joined: Fri Sep 01, 2017 10:04 pm
Location: Paris, FR

Re: Improving Timex/Sinclair Tape Loading

Post by Dim_75 » Thu Oct 26, 2017 1:07 am

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

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sirmorris
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Joined: Thu May 08, 2008 4:45 pm
Location: oxon, uk

Re: Improving Timex/Sinclair Tape Loading

Post by sirmorris » Thu Oct 26, 2017 9:00 am

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 :shock:

Don't be disheartened - keep at it! It's a very useful skill.

C
--=== ZXpand+ ... A more moderner all-in-one upgrade solution for ZX81 ===--
* SD/MMC storage * 32K Hires-capable RAM * AY sound chip * Joystick port * Serial *
* BASIC enhancements - plug & play * Reset button * Auto-boot facility *

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