Re: [Ql-Users] Q60 + OSSC
On Wed, 15 Jan 2020 23:07:53 +0100, Peter Graf via Ql-Users wrote: > Those are small PLDs, optimized almost to the last gate, not FPGAs, > and 800x600 is not doable. Surprising, since it's "just" a change in divisors/counters/ frequencies, but if you say so (I'm certainly no expert in PLD/FPGA programming). > I would find an answer to my original question interesting. As I already explained, the OSSC has brought to me the solution for the Q60 (and since a 800x600 mode is ruled out, I don't see any point in modifying it now). But you'd have to ask other Q40/Q60 owners about what they would prefer (i.e. the use of a scan converter (*), or a heavy modification of their Qx0 to output a higher resolution compatible with modern monitors). Thierry. (*) In fact, a "cut-down" OSSC (that would only be able to deal with the Q40/Q60 and QL video modes, and with just the VGA input and no LCD display, no remote) could be a cheaper and easier solution. ___ QL-Users Mailing List
Re: [Ql-Users] Q60 + OSSC
Thierry Godefroy wrote: >> Besides lack of time and the BGA soldering issue, I remain unsure if >> such a massive board modification is appropriate for a historic computer. >> >> A lot depends on the question, what do we actually prefer today: Keeping >> the historic machine alive, or any 68060 machine that has decent video >> and runs SMSQ/E? > > That's why I always suggested a 800x600 SVGA mode to replace the 1024x512 > one... Granted, you loose 44288 pixels, but 800x600 is totally decent and > workable (under both SMSQ/E and Linux), and won't require any additional > VRAM, "just" needing a reprogramming of the FPGA(s) (or so is my wild > guess). Those are small PLDs, optimized almost to the last gate, not FPGAs, and 800x600 is not doable. I would find an answer to my original question interesting. ___ QL-Users Mailing List
Re: [Ql-Users] Q60 + OSSC
On Wed, 15 Jan 2020 17:40:26 +0100, Peter Graf via Ql-Users wrote: > Thierry Godefroy wrote: > > In fact, I found out today that by increasing the sample rate to 1260 (from > > the 1200 I used so far) on the OSSC, I could get it to output a 1024x512 > > (without scan doubling) or 2048x1024 (with it) resolution in the 480p HDMI > > signal format... and the good news is that the monitor accepts it ! > > What does the OSSC do then... > > a) scale 512 to 480 vertical pixels? > b) somehow make the monitor display a 512 pixel signal? > c) just output 480 pixels, and 32 lines are lost? It's b) As you can see on the high res photos, the monitor menu displays the input resolution: 1024x512 (without x2 scan) or 2048x1024 (with it)... That's why with the 1260 scan rate I get a pixel-perfect picture (or very, very close to it, and certainly as good as, if not better than, what my old 17" CRT can display). > > Very interesting, since the best solution would indeed be to gain a > > standard resolution output on the Q60. > > My personal preference would be a solution that includes more VRAM, so > it is not interpolated, but an actually usable resolution. > > Besides lack of time and the BGA soldering issue, I remain unsure if > such a massive board modification is appropriate for a historic computer. > > A lot depends on the question, what do we actually prefer today: Keeping > the historic machine alive, or any 68060 machine that has decent video > and runs SMSQ/E? That's why I always suggested a 800x600 SVGA mode to replace the 1024x512 one... Granted, you loose 44288 pixels, but 800x600 is totally decent and workable (under both SMSQ/E and Linux), and won't require any additional VRAM, "just" needing a reprogramming of the FPGA(s) (or so is my wild guess). You then get both of "keeping the historic machine alive" and a "68060 machine that has decent video and runs SMSQ/E"... :-P It might as well be possible to "cheat" a bit with nowadays' LCD monitors, and see if they can be persuaded to display a 800x640 mode (i.e. to sync 640 lines in each frame with timings close enough to a true 800x600 mode), which would be only 12288 less pixels when compared to 1024x512... This said, the OSSC totally does the job for me, and I'm not worried any more about the remaining lifetime of my last CRT (which I repaired myself twice already, so I don't expect it to survive much longer)... Regards, Thierry. ___ QL-Users Mailing List
Re: [Ql-Users] Q60 + OSSC
Thierry Godefroy wrote: > In fact, I found out today that by increasing the sample rate to 1260 (from > the 1200 I used so far) on the OSSC, I could get it to output a 1024x512 > (without scan doubling) or 2048x1024 (with it) resolution in the 480p HDMI > signal format... and the good news is that the monitor accepts it ! What does the OSSC do then... a) scale 512 to 480 vertical pixels? b) somehow make the monitor display a 512 pixel signal? c) just output 480 pixels, and 32 lines are lost? >> I have been generating 1024x768 @ 60 Hz DVI/HDMI directly from $5 FPGA >> with only moderate overclocking, maybe that leads to a better Q60 >> solution one day. > > Very interesting, since the best solution would indeed be to gain a > standard resolution output on the Q60. My personal preference would be a solution that includes more VRAM, so it is not interpolated, but an actually usable resolution. Besides lack of time and the BGA soldering issue, I remain unsure if such a massive board modification is appropriate for a historic computer. A lot depends on the question, what do we actually prefer today: Keeping the historic machine alive, or any 68060 machine that has decent video and runs SMSQ/E? >> At the moment I still struggle with manual BGA soldering. > > I never tried that myself... There are a few interesting videos on > Youtube about it, in particular this one: > https://www.youtube.com/watch?v=L8EWqWj2srg Using a hot air gun like in that video looks even more difficult than the IR lamp I'm experimenting with. All the best Peter ___ QL-Users Mailing List
Re: [Ql-Users] Q60 + OSSC
On Tue, 14 Jan 2020 01:16:14 +0100, Peter Graf via Ql-Users wrote: > Many thanks for taking a highres picture. It is nice to get the screen > filled, still single pixels can not be distinguished in every area. The > picture is significantly clearer on my 1024x768 monitor using the "black > bar" CPLD workaround. Hard to tell what I'd actually prefer, unless I try. In fact, I found out today that by increasing the sample rate to 1260 (from the 1200 I used so far) on the OSSC, I could get it to output a 1024x512 (without scan doubling) or 2048x1024 (with it) resolution in the 480p HDMI signal format... and the good news is that the monitor accepts it ! Here are the new high resolution pictures I took: http://qdos.free.fr/images/Q60-1024x512.dng http://qdos.free.fr/images/Q60-2048x1024.dng They are almost pixel-perfect. For a comparison between the OSSC+LCD solution with a CRT 17" monitor, here are a couple more pictures (at a lower resolution so that you can compare them side by side): http://qdos.free.fr/images/OSSC-Q60.png http://qdos.free.fr/images/CRT-Q60.png As you can see, the OSSC and LCD monitor perform quite well... > I have been generating 1024x768 @ 60 Hz DVI/HDMI directly from $5 FPGA > with only moderate overclocking, maybe that leads to a better Q60 > solution one day. Very interesting, since the best solution would indeed be to gain a standard resolution output on the Q60. > At the moment I still struggle with manual BGA soldering. I never tried that myself... There are a few interesting videos on Youtube about it, in particular this one: https://www.youtube.com/watch?v=L8EWqWj2srg Thierry. ___ QL-Users Mailing List
