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Re: Reset button
Posted: Sun Oct 27, 2013 8:28 pm
by skagon
1024MAK wrote:...I did not think that it was easily removable/replaceable.
The only thing I can safely say it is, is
easily breakable...

Re: Reset button
Posted: Sun Oct 27, 2013 8:31 pm
by RWAP
Dead easy to remove / replace - the plastic top of the soldered part just lifts up and out springs the red part (normally about 5 feet across the room)....
Re: Reset button
Posted: Sun Oct 27, 2013 8:58 pm
by vanpeebles
Sounds like those old toy tanks that fired matchsticks

Re: Reset button
Posted: Sun Oct 27, 2013 9:02 pm
by RWAP
Pretty much the same amount of fun - although finding the spring afterwards is a real pain!!
Re: Reset button
Posted: Sun Oct 27, 2013 9:47 pm
by dilwyn
RWAP wrote:Dead easy to remove / replace - the plastic top of the soldered part just lifts up and out springs the red part (normally about 5 feet across the room)....
...or direct into Rich's eye!

Re: Reset button
Posted: Sun Oct 27, 2013 10:19 pm
by 1024MAK
And very easy to prevent the err, "gun" from firing - just use your finger to stop it!
Mark
Re: Reset button
Posted: Mon Oct 28, 2013 3:08 pm
by Mr_Navigator

- Untitled-1.png (10.02 KiB) Viewed 7219 times
From what I can see the RESET button on both issue 5 and issue 6 simply grounds the RESET in on the ZX 8302 ULA. This is not a special switch and could be replaced by a push to close momentary action push-button and couple of fly leads carefully soldered in. If you after authenticity however that is a different matter.
I was in the process of recreating the circuit diagram for issue 5 to a very high quality one, only to lose all my work after a catastrophic drive failure and no back-up. I do intend to start again but cannot find where I originally got the image files from. There were about 8 that made up both Issue 5 and 6 and I used these as a template to which I overlayed vector equivalents. Anyone know where I can get them?
I checked Google and Dilwyn's site, the quality is too poor to identify component values.
Re: Reset button
Posted: Mon Oct 28, 2013 3:32 pm
by tofro
Lee,
There is a QL Service Manual on World of Sinclair that has a bit better scan quality (I think) than the one on Dilwyn's site (It's also OCR-ed and thus searchable)
ftp://ftp.worldofspectrum.org/pub/sincl ... Manual.pdf
Regards,
Tobias
Re: Reset button
Posted: Mon Oct 28, 2013 3:38 pm
by 1024MAK
More on schematics and service manuals
here
Mark
Re: Reset button
Posted: Mon Oct 28, 2013 4:52 pm
by skagon
Mark, I've got a service manual right here. Printed, that is. Unfortunately, no scanner, but I doubt it'd be of much use as the schematic pages are bigger than A3.
Anyway, I know what the Reset button connects to and I've got a momentary switch hooked, I just don't like the idea of a dangling switch hanging out of the hole. And yes, I am looking for originality. However, I had another look this morning and it seems I was probably looking at something else, since the button is a plain DPDT with normal pin pitch so it can be found. I've already checked DigiKey's bible and I've spotted one or two possible replacements. Won't have the black cap but... what can you do.
However, if I manage to fix that QL (it's the one with the RAM error), it might be an idea to get it converted to desktop. Properly. And use one of those nifty keyboard interfaces too. That's not a bad idea... so the broken reset button can be removed and headers attached to get a reset button in front.