Re: [Ql-Users] Connecting a QL to a VGA Monitor
Hi everyone, thanks to Miguel's example I ordered a GBS-8220 rgb converter from jammaboards.com. I received the unit yesterday ten days after ordering and managed to build a cable and try it out. 512x256 works fine. Unfortunately my Samsung display has a 1280x1024 native resolution with no letterboxing available so the picture is not as perfect as it could be. The converter board's closest resolution match is 1024x768. Overall image quality is fair. There seems to be some vertical jitter every now and then but it could be either the cable (not premium and a very average soldering job...) or my QL which does not display a rock solid picture through SCART to a tv. My first impression is that the board is well worth the 39 USD it cost. The automatic scan worked perfectly once I figured out to connect composite, not vertical, sync from the QL to the sync input on the RGBS connector :) The occasional jitter does not bother me too much, the overall experience is still better than on the TV since I'm able to use 512x256. With a monitor that supports letterboxing the experience might be slightly better. I'm using an original QL with no extensions running a JS ROM. Cheers, Petri On Wed, Sep 15, 2010 at 4:05 PM, Miguel Angel Rodriguez Jodar miguel.an...@zxprojects.com wrote: El 15/09/2010 14:17, Peter escribió: Miguel Angel Rodriguez Jodar wrote: On the other way, I've managed to work it out using a RGB-to-VGA converter, as used for connecting JAMMA boards to VGA monitors. Did you have to use the QL in TV mode or did full 512x256 work? Mmmm... I cannot remember... will try again this weekend, and will tell you. Which QL did you use? A standard QL, english keyboard, Minerva 1.98. ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
Hi Miguel, The monitor used was a PS/1 VGA one, and I did take a photo (phone camera) of the thing connected to a standard QL running in MODE 4. This is what I saw: http://www.atc.us.es/~rodriguj/ql_composite_to_vga.jpg Thank you. It seems that part of the screen is cut off :-( Also the picture seems noisy. By the way, that's why Thierry's statement 8 colours need no A/D neither D/A should not be taken literally. Even if the digital resolution is only 1 bit, you still have conversion from/to analogue signals, and this requires exact thresholds, levels and very low noise. I remember a tinkerer who built an Atari monochrome graphics card and forgot this - his first PCB was in vain although the digital part was fine.) All the best Peter ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
Phil Kett wrote: There are devices available that will take a scart RGB signal and convert it so that it will work on a modern SVGA or LCD monitor. Here's one from Maplins. http://www.maplin.co.uk/Module.aspx?ModuleNo=217685 Have you actually tried with a QL? My experience with similar converters: - Part of the 512x256 screen is cut off - Screen sometimes jumps vertically Not being able to connect the QL to a modern monitor is a major problem. Sometimes I even considered to build a QL video card to overcome this. Miguel Angel Rodriguez Jodar wrote: On the other way, I've managed to work it out using a RGB-to-VGA converter, as used for connecting JAMMA boards to VGA monitors. Did you have to use the QL in TV mode or did full 512x256 work? Which QL did you use? All the best, Peter ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
El 15/09/2010 14:17, Peter escribió: Miguel Angel Rodriguez Jodar wrote: On the other way, I've managed to work it out using a RGB-to-VGA converter, as used for connecting JAMMA boards to VGA monitors. Did you have to use the QL in TV mode or did full 512x256 work? Mmmm... I cannot remember... will try again this weekend, and will tell you. Which QL did you use? A standard QL, english keyboard, Minerva 1.98. ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
Thierry Godefroy wrote: There are devices available that will take a scart RGB signal and convert it so that it will work on a modern SVGA or LCD monitor. Here's one from Maplins. http://www.maplin.co.uk/Module.aspx?ModuleNo=217685 Have you actually tried with a QL? My experience with similar converters: - Part of the 512x256 screen is cut off - Screen sometimes jumps vertically Not being able to connect the QL to a modern monitor is a major problem. Sometimes I even considered to build a QL video card to overcome this. None of the converters I could find on the market can display properly a QL screen (both 512x256 and 256x256) on a VGA screen... they either completly fail to sync the display, or they interpolate and sample each line in 640 pixels, which distorts unevenly both the QL pixels and colors, making any text unreadable. The definitive solution would be a programmable converter, able to rebuild the pixel clock from both the VSYNC signal and the actual number of pixels per line of the QL (counting blanking time pixels too), and then to sample the video signal from this rebuilt pixel clock. The samples would then have to be stored in a memory, and each frame would have to be centered in a 600x350 or 640x480 VGA picture. This would be doable by a engineer in electronics... Thierry. It would be interesting to have someone with knowledge of the hardware (for example, Peter) compare the cost and complexity of the two possible approaches: (1) adapt the existing QL video signal, taking into account the difficulties noted here, and (2) a different approach as Peter alluded to, the possibility of a new QL video system, examples of approaches I can think of include what Nasta did with Aurora video, and what Miracle proposed to do with the Masterpiece video update originally. As I have said before on this list, I have been asked * MANY * times how to connect an SVGA monitor to a QL! I don't really care whether it's done via a converter or reasonably simple to install video card, whoever can come up with a reasonably priced and fairly simple to install solution is on to a winner given that it's becoming harder and harder to find a dedicated QL monitor these days. I will retreat to a safe distance and await (fear?) the responses :-) Dilwyn Jones ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
Thierry, a video converter is certainly doable. Instead of 640x480, I would use 1024x768 and double/triple the 512x256 QL pixels. Timings would require an individual (automatic) adjustment, and a facility to save the result in a non-volatile manner. Such a converter would require an FPGA and RAM anyway, so a graphics card which plugs into the CPU socket is the about the same amount of work. It would allow additional gimmicks like SD card interface, and not require conversion of analogue signals. All the best Peter ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
Does anyone have any thoughts as to whether this would work - and could it be used to connect to a more modern SVGA? I'm afraid it won't work at all. It's a real pity modern SVGA's don't do multisync as in the good old days :( On the other way, I've managed to work it out using a RGB-to-VGA converter, as used for connecting JAMMA boards to VGA monitors. I wrote a review (spanish, but with a lot of pictures, so even without translation you'll get an idea) about it here: http://www.zonadepruebas.com/modules/smartsection/item.php?itemid=1225 An English translation (machine translation, but readable) can be seen at: http://translate.google.co.uk/translate?u=http%3A%2F%2Fwww.zonadepruebas.com%2Fmodules%2Fsmartsection%2Fitem.php%3Fitemid%3D1225sl=estl=enhl=ie=UTF-8 Dilwyn Jones ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
[Ql-Users] Connecting a QL to a VGA Monitor
A customer has passed an interesting little webpage (in Spanish) to me about connecting a QL to a VGA monitor - http://www.speccy.org/sinclairql/articulos/bricolaje/RGB_VGA.html see url:http://translate.google.com/translate?js=nprev=_thl=enie=UTF-8layout=2eotf=1sl=autotl=enu=http%3A%2F%2Fwww.speccy.org%2Fsinclairql%2Farticulos%2Fbricolaje%2FRGB_VGA.htmlact=url for the English translation Does anyone have any thoughts as to whether this would work - and could it be used to connect to a more modern SVGA? -- Rich Mellor RWAP Services http://www.rwapsoftware.co.uk http://www.rwapservices.co.uk -- Try out our new site: http://sellmyretro.com ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
On Sat, 04 Sep 2010 09:51:03 +0200, Rich Mellor r...@rwapservices.co.uk wrote: A customer has passed an interesting little webpage (in Spanish) to me about connecting a QL to a VGA monitor - http://www.speccy.org/sinclairql/articulos/bricolaje/RGB_VGA.html see url:http://translate.google.com/translate?js=nprev=_thl=enie=UTF-8layout=2eotf=1sl=autotl=enu=http%3A%2F%2Fwww.speccy.org%2Fsinclairql%2Farticulos%2Fbricolaje%2FRGB_VGA.htmlact=url for the English translation Does anyone have any thoughts as to whether this would work - and could it be used to connect to a more modern SVGA? I don't think you'll find any modern monitor supporting 16KHz horizontal synch which I believe the QL supplies. Kjartan ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
A customer has passed an interesting little webpage (in Spanish) to me about connecting a QL to a VGA monitor - http://www.speccy.org/sinclairql/articulos/bricolaje/RGB_VGA.html see url:http://translate.google.com/translate?js=nprev=_thl=enie=UTF-8layout=2eotf=1sl=autotl=enu=http%3A%2F%2Fwww.speccy.org%2Fsinclairql%2Farticulos%2Fbricolaje%2FRGB_VGA.htmlact=url for the English translation Does anyone have any thoughts as to whether this would work - and could it be used to connect to a more modern SVGA? I don't think you'll find any modern monitor supporting 16KHz horizontal synch which I believe the QL supplies. Kjartan It's a real pity that this is not possible. It's one of the most commonly asked questions I receive through my website and Quanta helpline, concerning connecting SVGA monitors to a QL. If there was a way to build a conversion circuit I'm sure it would be very popular based on the number of times I've been asked. Dilwyn Jones ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
On 04/09/2010 13:01, Dilwyn Jones wrote: A customer has passed an interesting little webpage (in Spanish) to me about connecting a QL to a VGA monitor - http://www.speccy.org/sinclairql/articulos/bricolaje/RGB_VGA.html see url:http://translate.google.com/translate?js=nprev=_thl=enie=UTF-8layout=2eotf=1sl=autotl=enu=http%3A%2F%2Fwww.speccy.org%2Fsinclairql%2Farticulos%2Fbricolaje%2FRGB_VGA.htmlact=url for the English translation Does anyone have any thoughts as to whether this would work - and could it be used to connect to a more modern SVGA? I don't think you'll find any modern monitor supporting 16KHz horizontal synch which I believe the QL supplies. Kjartan It's a real pity that this is not possible. It's one of the most commonly asked questions I receive through my website and Quanta helpline, concerning connecting SVGA monitors to a QL. If there was a way to build a conversion circuit I'm sure it would be very popular based on the number of times I've been asked. Dilwyn Jones There are devices available that will take a scart RGB signal and convert it so that it will work on a modern SVGA or LCD monitor. Here's one from Maplins. http://www.maplin.co.uk/Module.aspx?ModuleNo=217685 Phil ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Connecting a QL to a VGA Monitor
El 04/09/2010 9:51, Rich Mellor escribió: Does anyone have any thoughts as to whether this would work - and could it be used to connect to a more modern SVGA? I'm afraid it won't work at all. It's a real pity modern SVGA's don't do multisync as in the good old days :( On the other way, I've managed to work it out using a RGB-to-VGA converter, as used for connecting JAMMA boards to VGA monitors. I wrote a review (spanish, but with a lot of pictures, so even without translation you'll get an idea) about it here: http://www.zonadepruebas.com/modules/smartsection/item.php?itemid=1225 ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
