|
Post by Pyrofer on Sept 11, 2019 8:02:20 GMT
So here is a question. The VDC uses a 16mhz dotclock. After doing a lot of math I came to the conclusion that it has 1024 pixels per line. That includes 640 visible, 160(ish) border pixels and the rest lost in blanking and sync pulses.
However, that does not appear to be the case. Does anybody know more about the actual way the VDC pushes pixels can tell me?
I am trying to convert my scandoubler from a working "line doubler" that only does a line at a time to a full frame doubler. However, I can't get a solid image with the 1024 pixel width assumption.
I am now not sure if it's a hardware problem my end or my assumption about the VDC output is wrong.
I know there are people here who worked on C128 emulators so I would greatly appreciate their input.
|
|
|
Post by Pyrofer on Sept 2, 2019 14:04:11 GMT
what vsync frequency does it generate? I am interested in why it didn't work with the scandoubler, does it fiddle with hsync too? Do you have details of the actual output frequencies when using it? I guess I need to devote some time to looking at it, but plenty of other things to do
|
|
|
Post by Pyrofer on Sept 2, 2019 7:13:10 GMT
I tried on my 15khz capable BenQ VGA LCD, it didn't work. I also tried on 2 VGA monitors with the scandoubler attached to get 31khz, It still didn't work. I don't have a 15khz CRT available to me. I guess I could try it in a SCART TV but as I won't usually be using that I didn't bother. I may try it on a CRT VGA monitor if I get bored...
|
|
|
Post by Pyrofer on Sept 1, 2019 15:56:50 GMT
I couldn't get this to display at all Both my monitors just said out of range, with and without the linedoubler. That IS a shame, I guess I don't get to play with it.
|
|
|
Post by Pyrofer on Aug 31, 2019 15:38:43 GMT
Can you list the register changes you made? I would like to try this...
|
|
|
Post by Pyrofer on Aug 31, 2019 12:23:54 GMT
How does the 50lines non-interlace work?
|
|
|
Post by Pyrofer on Aug 29, 2019 22:28:09 GMT
I have a few built, I am weary of selling them as they need rather complex installation! If you are confident you can attach the jumper wires correctly and have a JiffyDos with a manual switch you can control that too PM me.
|
|
|
Post by Pyrofer on Aug 24, 2019 12:34:30 GMT
The 128 has oodles of ram. Surely it's just about allocation? You would lose ram in one place to make room for another. Reduce the amount of basic ram? I am not sure where/how that particular ram is allocated but I would be VERY surprised if you couldn't jiggle it around to make it fit. Sadly, this would be quite a major change to the rom that "might" break some stuff, but I would hope not. You could always have it switchable like JiffyDos often is.
|
|
|
Post by Pyrofer on Aug 23, 2019 14:01:48 GMT
Ah. Well, unless somebody supplies the software I guess it's a no then I have a working cart and I am happy to test anything, I will message them and see if they got around to writing any software. I wonder if the easyflash guys could help?
|
|
|
Post by Pyrofer on Aug 21, 2019 7:27:51 GMT
I havent even tried. No idea if it's possible. Do you have reason to suspect it is?
|
|