Hello from Virginia!

Introduce yourself to your fellow forum members - what was your journey into the Sinclair world?
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gammaray
Posts: 257
Joined: Sun Apr 17, 2016 1:44 am
Location: Texas

Re: Hello from Virginia!

Post by gammaray » Fri May 19, 2017 12:36 am

I concur. This idiot installed composite video mod without any problem save for adjustment of pots.
Finish what you start. Truth is over the mountaintop or six feet under.
4 x TS1000, 2 x TS1500 , 2 x timex 2040 printer, 1/2 x timex 2020 cassette deck, ZXPAND, ZeddyNET, ZXBlast..., unfinished Spectrum...Still no life!

Papa_Bear
Posts: 18
Joined: Fri Apr 07, 2017 2:11 pm

Re: Hello from Virginia!

Post by Papa_Bear » Fri May 19, 2017 1:43 am

I was trying to make a composite video buffer off PIN 16 and the +5v pin of the RF box. with the transistor and resistor. I'm buying a 2600 premade board which has been proven to work on the TS-1000

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amigaman07
Posts: 35
Joined: Thu May 04, 2017 5:34 am
Location: Newcastle Australia

Re: Hello from Virginia!

Post by amigaman07 » Fri May 19, 2017 2:36 am

Papa_Bear wrote:
Fri May 19, 2017 1:43 am
I was trying to make a composite video buffer off PIN 16 and the +5v pin of the RF box. with the transistor and resistor.
Pin 16 of What??? I have not done this MOD on a ZX81 before.

The ZX Spectrum 48k Composite MOD just Requires a 10-16V 100uF Capacitor on the +5V Rail of RF Modulator and to Center Pin of RF Out Jack. (Once all the Original RF Circuitry has been Removed)

I have also experimented with this Same MOD on the ZX81, and it Does Work, but Picture is Darker. Will play with this and Up-Date if / when successful.

Darren in OZ

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

Re: Hello from Virginia!

Post by Paul » Fri May 19, 2017 4:49 am

Please don't try a video out on the ZX81 without at least a transistor. Preferably use Pokemons ccp pcb. It gives a crystal clear picture.
Pin 16 of the ULA is video out.
But the ULA is VERY sensitive. Any static voltage or any low resistance (like 75 ohm) can kill the ULA.
Maybe your monitor didn't have the obligatory 75 ohm resistance. Then you were very lucky. But the next monitor you try can have this and your ULA will die.
On the spectrum video out doesn't come from the ULA directly but from a chip that mixes RGB to composite which is more robust.
Kind regards Paul
In theory, there is no difference between theory and practice. But, in practice, there is.

Papa_Bear
Posts: 18
Joined: Fri Apr 07, 2017 2:11 pm

Re: Hello from Virginia!

Post by Papa_Bear » Fri May 19, 2017 5:16 am

There was a transistor involved and was grounded. Like I've said this isn't going to be perfect.


Can the TS-1000 turn on without a keyboard?

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Paul
Posts: 860
Joined: Thu May 27, 2010 7:15 am
Location: Germanys west end

Re: Hello from Virginia!

Post by Paul » Fri May 19, 2017 9:07 am

Yes no problem no keyboard needed.
Also no Message "keyboard not present. Press F1 to continue" :mrgreen:
Last edited by Paul on Fri May 19, 2017 9:11 am, edited 1 time in total.
In theory, there is no difference between theory and practice. But, in practice, there is.

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Paul
Posts: 860
Joined: Thu May 27, 2010 7:15 am
Location: Germanys west end

Re: Hello from Virginia!

Post by Paul » Fri May 19, 2017 9:10 am

Papa_Bear wrote:
Fri May 19, 2017 5:16 am
There was a transistor involved and was grounded.
My comment on the ULA being very sensitive was aimed at Darren and any reader because his dangerous experiment.
In theory, there is no difference between theory and practice. But, in practice, there is.

Papa_Bear
Posts: 18
Joined: Fri Apr 07, 2017 2:11 pm

Re: Hello from Virginia!

Post by Papa_Bear » Fri May 19, 2017 2:17 pm

anyone have a spare TS1000 for sale in case I totally screw mine up? :D


What are some other peripherals for the ZX81 and TS1000. I saw a little printer going for a ridiculous amount on ebay.

Papa_Bear
Posts: 18
Joined: Fri Apr 07, 2017 2:11 pm

Re: Hello from Virginia!

Post by Papa_Bear » Wed May 24, 2017 8:02 pm

well... okay then


It doesnt seem to work properly

I'm following this mod using the same board

http://blog.tynemouthsoftware.co.uk/201 ... o-mod.html

I get an incredibly broken picture on my modern tv and no image on any of the crts I've tried

Papa_Bear
Posts: 18
Joined: Fri Apr 07, 2017 2:11 pm

Re: Hello from Virginia!

Post by Papa_Bear » Wed May 24, 2017 8:33 pm

Wait a minute. apparently there was a coil connecting to ground... I have video now! woo on the B&W CRT as well as my modern flat screen

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