Video problems when running games and... I am new

[bola_dor]

Hi.. I have my CZ1000 since 1984. It's an argentinian rebranded 2Kb TS1000 ISS-3 board still running..
Not without some issues ..
I have a faulty 16Kb ram pack.. with good voltages but that doesn't post.. after checking it I discovered tha The machine itself won't start any more giving me a wire screen.. Fortunately I have second working ram pack and everything seems to work fine with it attached.. so I think I killed the internal 2Kb chip trying to fix the 1st rampack..
I also made the one transistor composite video mod.. and it works really good.. (or I think so) ..
At this point I wanted to load something into "the machine" .. so I thought that using my Samsung cellphone to play some WAV should be a good Idea.. I couldn't... I tried with the original mono cables with no success.. then I'made may own cable wit a TRRS and TS miniplugs connecting T-T and S-S to avoid the T-S misconnection at the Zeddy side.. but.. didn't work..
Finally I gave up with the cellphone and used a notebook to play SPACEINV and MAZZOGS.. with the original TS mono plugs.. it worked!!!!... when executing LOAD "" the screen shows the oblique thin lines as always but when sound starts the screen blacks out.. or shows very dark thick bars but different from the original ones in the old CRT BW 14" TV.. so I've lost that feedback.. sound through TV is lost too... so.. I miss load feedback..

Now the Problem... both games started fine but at some point vertical position gets desync.. SPACEINV is very predictable.. when you're killed and a menu screen appears all is like scrolled up and wrapping down from up .. If I can stop the program and LIST it gets good again (like a soft reset) or I can un plug the video several times still it gets good again...
With MAZZOGS it more messy.. screen gets really scrambled when playing.. it can be solved the same way but it's unusable...
Vertical "interference" also appears at this moment.. else the screen is clean and clear ...
I have some theory.. if you run plain BASIC there is no problem at all.. I thin so.e routines messing with sync get things lost.. but I don't know if this is related to the ula,to tehe video out mod or the 60" led tv (I am using a 4.5m cable)..
Well sorry the length.. I am happy to find this forum..

[bola_dor]

Any one... please?
I tried on other two LCD TV but strangely them tell me "no signal" to composite video input..
So I guess may be something wrong with the one transistor mod??
Thanks...

[mrtinb]

I have the same problem. I've connected to a monitor, but it want's very exact video signal input.

One thing ZX81 does not give is very exact video signal output.

Even though I got Pokemon's ZX8-CCB composite mod, I still have problem with the video.

I guess old TVs like the 9" B/W TV I have, may be the only solution for a steady picture.

It's like winning the lottery finding a TV/monitor that works with the ZX81.

[Lardo Boffin]

I would imagine Pokemon’s ZX8-CCB board will produce a stronger signal than a simple transistor mod and is cheap and easy to install. I have so far bought about 30 of them, I think, for ZX81s I have refurbed and sold on eBay. I have not had any feedback from buyers that they could not get a picture from them.
However - as I say in my listings the signal is poor by modern standards and some TVs are more picky than others. Older TVs are always best but I test on a full HD LG 19” monitor, a full HD 37” Sony tv, a 14” glass screen telly and a 17” non-HD LCD tv.

The ZX8-CCB has two pots that can be adjusted to get the best picture. This may be enough to get a picture on your monitor?

You will not get on screen feedback during loading with the ZX8-CCB Basic but Pokemon does sell a ZX8-CCB Advanced with a sync generator that does this.

Another option is the Chroma 81 which plugs in and generates a screen directly from the computer and does not use the RF output. It is here - http://www.fruitcake.plus.com/Sinclair/ ... erface.htm
This gives on screen feedback during loading and produces a native SCART signal. Not sure if it will work with a clone though.

[Lardo Boffin]

When setting a ZX8-CCB I start from this position and then adjust as required based on the zeddie - each one needs tweaking slightly.

A non conductive screw driver is very useful as you can fine tune it with the zeddy switched on to get the perfect picture.

[mrtinb]

The ZX8-CCB has two pots that can be adjusted to get the best picture. This may be enough to get a picture on your monitor?

I know this. But what is tuned fine one day, is out of sync the next day. The monitor is very picky.

I even have to have the signal through a Composite2HDMI-converter, just to get a picture on the screen. Without the Composite2HDMI-converter, the screen just says 'No signal'. And this is even with ZX8-CCB connected and adjusted: 'No signal'.

Edit: I have written to Pokemon about the ZX8-CCB-SYNC version, which is currently out of stock.

[bola_dor]

I have the same problem. I've connected to a monitor, but it want's very exact video signal input.

One thing ZX81 does not give is very exact video signal output.

Even though I got Pokemon's ZX8-CCB composite mod, I still have problem with the video.

I guess old TVs like the 9" B/W TV I have, may be the only solution for a steady picture.

It's like winning the lottery finding a TV/monitor that works with the ZX81.

So you say that ZX8-CCB May not solvente this problem?
Thing is I have very good video when running plain basic but it seems that sync is lost at some point in the games routines..
Thanks!!

[bola_dor]

I would imagine Pokemon’s ZX8-CCB board will produce a stronger signal than a simple transistor mod and is cheap and easy to install. I have so far bought about 30 of them, I think, for ZX81s I have refurbed and sold on eBay. I have not had any feedback from buyers that they could not get a picture from them.
However - as I say in my listings the signal is poor by modern standards and some TVs are more picky than others. Older TVs are always best but I test on a full HD LG 19” monitor, a full HD 37” Sony tv, a 14” glass screen telly and a 17” non-HD LCD tv.

The ZX8-CCB has two pots that can be adjusted to get the best picture. This may be enough to get a picture on your monitor?

You will not get on screen feedback during loading with the ZX8-CCB Basic but Pokemon does sell a ZX8-CCB Advanced with a sync generator that does this.

Another option is the Chroma 81 which plugs in and generates a screen directly from the computer and does not use the RF output. It is here - http://www.fruitcake.plus.com/Sinclair/ ... erface.htm
This gives on screen feedback during loading and produces a native SCART signal. Not sure if it will work with a clone though.

I've looked at the chroma interfase .. the SCART connector is a rarity in my country.. I wonder how difficult is to adapt it to a composite or a video component video in .. or even a VGA/RGB..?
My CZ1000 is a plain TS1000 with a NTSC output.. TV sets in my countrie are NTSC and PAL-N , which won't have any problems with PAL-B output in B&W signals.. but I don't know how will it be with colour...
I see in your signature you have a TS1500 that is 100% compatible with a NTSC 60i fps.. does it work with the Chroma interface?
Thanks!!!

[bola_dor]

The ZX8-CCB has two pots that can be adjusted to get the best picture. This may be enough to get a picture on your monitor?

I know this. But what is tuned fine one day, is out of sync the next day. The monitor is very picky.

I even have to have the signal through a Composite2HDMI-converter, just to get a picture on the screen. Without the Composite2HDMI-converter, the screen just says 'No signal'. And this is even with ZX8-CCB connected and adjusted: 'No signal'.

Edit: I have written to Pokemon about the ZX8-CCB-SYNC version, which is currently out of stock.

I'll give a try to this.. what kind of composite to hdmi adaptors do you use??

[1024MAK]

RGB SCART uses three channels to carry colour with no separate monochrome signal. The channels are called red, green and blue to correspond with the three election guns in a colour CRT TV.

It is possible to convert from RGB SCART to composite video, but it takes rather a lot of electronics, so in your case is not a realistic option.

Video component is normally colour difference signals along with a monochrome video channel. So very different from RGB SCART.

VGA is a RGB system, but unless you have one of the rare monitors that can work at TV frequencies, it’s not a lot of help. Nearly all VGA monitors will only work with VGA specification video signals.

Mark