Search found 187 matches

by bola_dor
Tue Oct 29, 2019 11:38 pm
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

Hey bola_dor and everybody, I quoted that 1024MAK(Mark) has his "a simple transistor buffer" design. I put his own circuit design on a stripboard or a Veroboard to make our work more simpler and easier. I created a little cute Veroboard/stripboard project drawing based on 1024MAK's excellent ZX81 V...
by bola_dor
Sun Oct 20, 2019 2:16 am
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

Hey bola_dor and everybody, I quoted that 1024MAK(Mark) has his "a simple transistor buffer" design. I put his own circuit design on a stripboard or a Veroboard to make our work more simpler and easier. I created a little cute Veroboard/stripboard project drawing based on 1024MAK's excellent ZX81 V...
by bola_dor
Sat Oct 19, 2019 5:33 pm
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

Where are you picking up the composite video signal from on the PCB? Mark I've cut this wire inside the RF box.. it comes directly from the ULA (I checked that).. 5v was taken from the 3rd wire to the right, I think it changes from channel 2 to 3 between 2nd and 3rd wire with the selector at the bo...
by bola_dor
Sat Oct 19, 2019 5:08 pm
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

What about a HDMI upscaler? I have an Atari ST and on one of my tellies the picture rolls up the screen endlessly when using SCART. When I plug the SCART into a SCART to HDMI upscaler the picture is fine. Strange, I have several STFM’s and several STe’s and don’t have any problems using low and med...
by bola_dor
Sat Oct 19, 2019 1:56 pm
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

I don't think back porch is missing.. actually I had a clear image with the RF modulator and now I kind of regret about modifying it to the single transistor + resistor arrangement.. image now is sharper but I have this problem I think is something about Sync.. I saw your circuit schematic, as I do...
by bola_dor
Sat Oct 19, 2019 12:41 pm
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

Lardo Boffin wrote: Sat Oct 19, 2019 8:17 am What about a HDMI upscaler? I have an Atari ST and on one of my tellies the picture rolls up the screen endlessly when using SCART. When I plug the SCART into a SCART to HDMI upscaler the picture is fine.
I'm going to try that.. thanks
by bola_dor
Sat Oct 19, 2019 1:55 am
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

Loss of synchronisation on the the ZX80, ZX81, TS1000 and the various other clones can be down to a number of reasons. These machines use the CPU (with help from the glue logic or ULA) to generate the correct signal for the video output. In simple terms, the video is software generated. When runnin...
by bola_dor
Sat Oct 19, 2019 1:45 am
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

If your machine does not produce a video signal that includes the ‘back porch’ part of the video signal, my recommendation would be to try one of PokeMon’s ZX8-CCB devices. They are available here . These also have the advantage of producing a nice clear clean and sharp video output. I use them mys...
by bola_dor
Sat Oct 19, 2019 1:37 am
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

What about this kind off adapter, won't this work? https://www.retrogamingcables.co.uk/switched-scart-to-composite-video-adapter Those and similar devices just break out the appropriate SCART connections into separate connectors. They contain no electronics and are only useful if the SCART connecti...
by bola_dor
Fri Oct 18, 2019 2:04 am
Forum: Hardware
Topic: Video problems when running games and... I am new
Replies: 43
Views: 11113

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

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 y...