Hi,
I'm investigating phoenix arcade graphics. In your readme.txt you wrote:
"Background horizontal blanking start about one tile after foreground
horizontal
blanking. This allow to keep clean the top most foreground text line and for
cpu to update this shadowed line with new data (MAME missed that point. So
background graphix appears suddenly at top of the screen). There is also
about one line less at bottom of the screen."
I'm wondering what that means. Does it mean the background layer visible
resolution is
not 256x204 (as the foreground layer), but only 240x204 where the first
column of characters
(the first text line when looking at rotated screen) and the last column of
characters is not displayed?
What do you mean by "shadowed line" - do you mean 1 pixel line or 1
character line (8 pixels height)?
Do you mean there is a shadow - like a different color intensity?
Also, I noticed one weird graphical glitch when running MAME phoenix
machine. When the
big mothership arrives from the top of the screen (background layer
scrolling), the scrolling
suddenly stutters, like it does not move/scroll for one frame. I though it
might be because
of the different frame rate of the machine vs. refresh rate of my monitor
(61 Hz vs 60 Hz). But I
also tried to run the Z80 phoenix code on a MCU emulator where I synchronise
the emulated vblank
with the actual video hardware vblank and I can see this issue exists there
as well (all other scrolling
is smooth, except this one occasion when mothership arrives). Can you see
the same issue on your FPGA
implementation as well?
Hi,
I'm investigating phoenix arcade graphics. In your readme.txt you wrote:
"Background horizontal blanking start about one tile after foreground
horizontal
blanking. This allow to keep clean the top most foreground text line and for
cpu to update this shadowed line with new data (MAME missed that point. So
background graphix appears suddenly at top of the screen). There is also
about one line less at bottom of the screen."
I'm wondering what that means. Does it mean the background layer visible
resolution is
not 256x204 (as the foreground layer), but only 240x204 where the first
column of characters
(the first text line when looking at rotated screen) and the last column of
characters is not displayed?
What do you mean by "shadowed line" - do you mean 1 pixel line or 1
character line (8 pixels height)?
Do you mean there is a shadow - like a different color intensity?
Also, I noticed one weird graphical glitch when running MAME phoenix
machine. When the
big mothership arrives from the top of the screen (background layer
scrolling), the scrolling
suddenly stutters, like it does not move/scroll for one frame. I though it
might be because
of the different frame rate of the machine vs. refresh rate of my monitor
(61 Hz vs 60 Hz). But I
also tried to run the Z80 phoenix code on a MCU emulator where I synchronise
the emulated vblank
with the actual video hardware vblank and I can see this issue exists there
as well (all other scrolling
is smooth, except this one occasion when mothership arrives). Can you see
the same issue on your FPGA
implementation as well?
Thank you.
olin