White screen and no cursor at all

Discussions about Sinclair ZX80 and ZX81 Hardware
Lardo Boffin
Posts: 934
Joined: Sat Nov 26, 2016 2:42 am

Re: White screen and no cursor at all

Post by Lardo Boffin » Sun Jun 09, 2019 12:09 pm

Papalapa wrote:
Sun Jun 09, 2019 11:39 am
Lardo Boffin wrote:
Sat Jun 08, 2019 8:58 pm
Once you adjust the ZX8-CCB you should get a really good picture.

For later ULAs I start with this position and then fine tune:-


35DC1118-6135-4F8E-B637-8CCB59040850.jpeg


Yellow lines added for clarity. ;)

Before adjusting I always take a photo of the current position. Very useful when it gets worse. :o
R1 is totally turned to the right then?

This is the recommended position when do you start the adjust but later it seems that should be turned to the left. Anyway, if do you have a good video signal it doesn't matter..
Just checked my order history on Sell My Retro and it appears I have fitted 24 like this! I have not had to move R1 much from there on any of them.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500
TS 2000
Spectrum 16k (iss 1 s/n 1499)
Various Spectrum 48ks plus a DIVMMC future and SPECTRA

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1024MAK
Posts: 2315
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: White screen and no cursor at all

Post by 1024MAK » Sun Jun 09, 2019 7:16 pm

Lardo Boffin wrote:
Sun Jun 09, 2019 12:09 pm
Just checked my order history on Sell My Retro and it appears I have fitted 24 like this! I have not had to move R1 much from there on any of them.
I believe PokeMon sets them up for one ULA type before sending them out...
So you should only need to adjust them slightly if using the same ULA type.

24 :shock:

No wonder he does not think I am his favourite customer anymore!

We’ll have to call you the Del Boy of the Zeddy world at this rate :lol:

Mark

Lardo Boffin
Posts: 934
Joined: Sat Nov 26, 2016 2:42 am

Re: White screen and no cursor at all

Post by Lardo Boffin » Sun Jun 09, 2019 9:04 pm

1024MAK wrote:
Sun Jun 09, 2019 7:16 pm
Lardo Boffin wrote:
Sun Jun 09, 2019 12:09 pm
Just checked my order history on Sell My Retro and it appears I have fitted 24 like this! I have not had to move R1 much from there on any of them.
I believe PokeMon sets them up for one ULA type before sending them out...
So you should only need to adjust them slightly if using the same ULA type.

24 :shock:

No wonder he does not think I am his favourite customer anymore!

We’ll have to call you the Del Boy of the Zeddy world at this rate :lol:

Mark
I believe they are set up for the earlier ULAs. I tend to keep / not refurb those. They stay in the back of the three wheeler. :D
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500
TS 2000
Spectrum 16k (iss 1 s/n 1499)
Various Spectrum 48ks plus a DIVMMC future and SPECTRA

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Papalapa
Posts: 30
Joined: Wed May 01, 2019 4:52 pm
Location: Barcelona

Re: White screen and no cursor at all

Post by Papalapa » Mon Jun 10, 2019 8:45 am

1024MAK wrote:
Sun Jun 09, 2019 7:16 pm
Lardo Boffin wrote:
Sun Jun 09, 2019 12:09 pm
Just checked my order history on Sell My Retro and it appears I have fitted 24 like this! I have not had to move R1 much from there on any of them.
I believe PokeMon sets them up for one ULA type before sending them out...
So you should only need to adjust them slightly if using the same ULA type.

24 :shock:

No wonder he does not think I am his favourite customer anymore!

We’ll have to call you the Del Boy of the Zeddy world at this rate :lol:

Mark
That's right, he adjust the circuits for the 184 ULA by defect, but I have had this one on my ZX81 and even so the first startup was the screen completely white. After playing with the resistors I get a very good image of course.

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Papalapa
Posts: 30
Joined: Wed May 01, 2019 4:52 pm
Location: Barcelona

Re: White screen and no cursor at all

Post by Papalapa » Thu Jun 13, 2019 9:32 am

Well, finally I get an original C210 ULA for the second Zeddy and once installed is perfectly working.

Now is time to play with the TZXduino and the old software :D

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mrtinb
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Joined: Fri Nov 06, 2015 5:44 pm
Location: Denmark
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Re: White screen and no cursor at all

Post by mrtinb » Thu Jun 13, 2019 9:41 am

Great! :)
Martin
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube

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1024MAK
Posts: 2315
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: White screen and no cursor at all

Post by 1024MAK » Thu Jun 13, 2019 12:37 pm

👍 :D

Mark

Moggy
Posts: 1759
Joined: Wed Jun 18, 2008 2:00 pm

Re: White screen and no cursor at all

Post by Moggy » Thu Jun 13, 2019 12:43 pm

Now your journey begins! :D

Lardo Boffin
Posts: 934
Joined: Sat Nov 26, 2016 2:42 am

Re: White screen and no cursor at all

Post by Lardo Boffin » Thu Jun 13, 2019 4:48 pm

Excellent news!
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500
TS 2000
Spectrum 16k (iss 1 s/n 1499)
Various Spectrum 48ks plus a DIVMMC future and SPECTRA

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