Re: [Ql-Users] QL Video Card?
Peter Graf via Ql-Users wrote: >> Yes, this is true. That's the reason I have built a prototype of a >> bus-snooper that mirrors the QL screen on an HDMI monitor, but... damn >> it, now that you know I will never finish it :-) > Believe it or not, but when I wrote my remark this noon, I was actually > thinking "that could be something for Marcel Kilgus" now that he started > playing with FPGA. Really. > > My guess is that you'd use an FPGA with >=32 KB RAM, so why bus-snooping > and not fully replace the video area? Just to keep the original video > output alive? I've been thinking about this but I'm still probably not good enough to to pull this off using pure hardware, especially as my goal was HDMI which makes the task pretty much out of my league especially as not every FPGA can do the necessary TDMS signals (bought a Spartan board nonetheless if I ever wanted to try it ;) ) This was supposed to be a pure fun project for 2 or 3 evenings, so I got a GAL and a bunch of level shifter to connect a Raspberry Pi to the QL bus and did the rest in software. This is still not trivial as sampling the bus in the neccesary frequency can only be achieved bare metal, i.e. without any operating system running. But the video processor at least handles the whole HDMI stuff, which is neat. It almost worked before I stopped tinkering with it, it just showed ALL memory accesses, not just the ones to the screen memory ;-) Some problem with the address decoding in the GAL. Looked funny, but one could see the blinking cursor etc. Then the idea was to use an XC9572XL chip to do both level shifting and address decoding. After that I had the idea that instead of level shifting all the signals the CPLD could output them using a very fast SPI line instead as this would save a lot of lines. The Raspberry actually has a SPI slave function block, unfortunately nobody ever used it and therefore it seems to be pretty buggy. That's when time ran out around Christmas. Cheers, Marcel ___ QL-Users Mailing List
Re: [Ql-Users] QL Video Card?
I found this little snippet in my files that I thought you might enjoy :o) Per Masterpiece by Miracle Systems The long awaited GRAPHICS CARD, now titled the "Masterpiece Enhanced Graphics Card” will soon see the light of day. The targeted selling price is £50 (may change). The small circuit board will replace the 8301chip (for those who have been replacing 8301's the cost of the board alone is well worth being done with the 8301)) and will cause you to remove the 68008 if you hadn’t already done so. There are two displays, QL mode (512 x 512) or an enhanced graphics mode (1024 x 512 - requiring an SVGA non-interlaced monitor). Software to drive the new board will reside in a new ROM to be issued for the Super Gold Card (required for enhanced graphics). Masterpiece will have 128K of video ram on board. Those of you with Gold Cards will get the benefit of replacing the costly 8301 chip and the ability to upgrade in the future, who knows maybe the Super Gold Card or maybe even the Super-Duper Gold Card (the last one, at present is only in our publishers mind). What are you waiting for ?? Give yourself a Christmas present! I Call Miracle Systems for further information. 36 On 30/03/2018 01:28, Peter Graf via Ql-Users wrote: Am 29.03.2018 um 22:59 schrieb Marcel Kilgus via Ql-Users: (By the way, I wish Stuart had finished his QL Graphics Card, because all the video converters I tried with my QLs suck.) Yes, this is true. That's the reason I have built a prototype of a bus-snooper that mirrors the QL screen on an HDMI monitor, but... damn it, now that you know I will never finish it :-) Believe it or not, but when I wrote my remark this noon, I was actually thinking "that could be something for Marcel Kilgus" now that he started playing with FPGA. Really. My guess is that you'd use an FPGA with >=32 KB RAM, so why bus-snooping and not fully replace the video area? Just to keep the original video output alive? How would you work around the HDMI licensing costs issue? Personally, I still prefer VGA, because I also have some older monitors and converting VGA to HDMI can be done by small cheap dongles. Peter ___ QL-Users Mailing List ___ QL-Users Mailing List
