Post by mrbombermillzy on Mar 26, 2017 20:34:18 GMT
Ok. After several months of hibernation, I have now managed to find a C128D with keyboard in front of me again. So this weekend, I went back to some old projects I had waiting on the back burner.
My main project is still at the early experimentation stage, but as an aside, I revisited the old high resolution settings and have found an alternative method of setting 1024 pixels horizontally which causes less strain on the monitor, if not the VDC itself.
This subject was explained in more detail in my previous thread on the subject: c-128.freeforums.net/thread/303/new-higher-resolution-c128-mode
Basically, I was 'stealing' sync pulse time to force more characters into the frame. When getting to the 127 total char limit, the coloiur luminance/saturation were becoming very subdued and the monitor was on its display limits.
What I have now discovered is that I can actually increase the total chars (reg 0) up to 160 with some CAREFUL manipulations of the h.sync position and then the total displayed chars can be increased up to 128 without actually cutting into the h.sync pulse width!
Heres a picture of my Aydin Ranger displaying the full 1024px which it couldnt do before (~960px max before):
So the magic register combination to set for 1024x200 is:
Register Value
0 160
1 128
2 153
35 106
This is far more 'monitor friendly' and there may even be a way around the char corruption issues. (I havent had a chance to test that side of things though).
However, its not all plain sailing as, depending on your hardware, you may need to change the register values a small amount at a time; particularly registers 0 and 2. The trick is to slowly adjust the values a bit at a time alternatively, keeping the display slightly to the left of center. Any large adjustments (or small ones when too near the center of the screen) will cause the VDC to freak out and cause a loss in 'character composure'.(?) Yeah, maybe a photo of what it looks like is in order:
This is not rolling or moving at all. Just garbled!
I found the best (read quickest) way to 'climb the ladder' to the higher settings without losing the display was to set the following in this specific order:
Register Value
0 145
2 123
0 155
2 135
0 160
Please note: milage may vary on your hardware! With that in mind, this was all possible on my more fragile C= Ranger monitor, so a lot of you should have a fair chance with this!
I havent tried on any of my more bulletproof Sony PVM's yet. (I cant find my RGBi >RGBa lead ATM).
And as a bonus, it looks like using this method could possibly result in yet higher attainable horizontal resolutions!
I was actually aiming to give you a register setting for a 1280x200 resolution, but having to work blind changing registers slowed things down and I finally run out of time and needed to attend to 'real life'. However, here is a photo of it getting real close:
Displayed chars is set at 80, so there is around 100% more space available to the left/right.
As you can see (probably more so in the first picture), either the char/dot clk or the monitor pixel width is shot, with pixels getting very much smaller the nearer to both edges the chars get. I will try to alleviate this, but at least you get to see the higher res picture, warts and all.
With a bit of luck, I should have it cracked next weekend (or explain why not!)
TLDR: Less stress on the monitor, more for the VDC!
More updates when I have more time!
My main project is still at the early experimentation stage, but as an aside, I revisited the old high resolution settings and have found an alternative method of setting 1024 pixels horizontally which causes less strain on the monitor, if not the VDC itself.
This subject was explained in more detail in my previous thread on the subject: c-128.freeforums.net/thread/303/new-higher-resolution-c128-mode
Basically, I was 'stealing' sync pulse time to force more characters into the frame. When getting to the 127 total char limit, the coloiur luminance/saturation were becoming very subdued and the monitor was on its display limits.
What I have now discovered is that I can actually increase the total chars (reg 0) up to 160 with some CAREFUL manipulations of the h.sync position and then the total displayed chars can be increased up to 128 without actually cutting into the h.sync pulse width!
Heres a picture of my Aydin Ranger displaying the full 1024px which it couldnt do before (~960px max before):
So the magic register combination to set for 1024x200 is:
Register Value
0 160
1 128
2 153
35 106
This is far more 'monitor friendly' and there may even be a way around the char corruption issues. (I havent had a chance to test that side of things though).
However, its not all plain sailing as, depending on your hardware, you may need to change the register values a small amount at a time; particularly registers 0 and 2. The trick is to slowly adjust the values a bit at a time alternatively, keeping the display slightly to the left of center. Any large adjustments (or small ones when too near the center of the screen) will cause the VDC to freak out and cause a loss in 'character composure'.(?) Yeah, maybe a photo of what it looks like is in order:
This is not rolling or moving at all. Just garbled!
I found the best (read quickest) way to 'climb the ladder' to the higher settings without losing the display was to set the following in this specific order:
Register Value
0 145
2 123
0 155
2 135
0 160
Please note: milage may vary on your hardware! With that in mind, this was all possible on my more fragile C= Ranger monitor, so a lot of you should have a fair chance with this!
I havent tried on any of my more bulletproof Sony PVM's yet. (I cant find my RGBi >RGBa lead ATM).And as a bonus, it looks like using this method could possibly result in yet higher attainable horizontal resolutions!
I was actually aiming to give you a register setting for a 1280x200 resolution, but having to work blind changing registers slowed things down and I finally run out of time and needed to attend to 'real life'. However, here is a photo of it getting real close:
Displayed chars is set at 80, so there is around 100% more space available to the left/right.
As you can see (probably more so in the first picture), either the char/dot clk or the monitor pixel width is shot, with pixels getting very much smaller the nearer to both edges the chars get. I will try to alleviate this, but at least you get to see the higher res picture, warts and all.
With a bit of luck, I should have it cracked next weekend (or explain why not!)
TLDR: Less stress on the monitor, more for the VDC!
More updates when I have more time!
