My wish list,
I wish that everyone would stop trying to reproduce all the Apple II's
screens and just give me one device that can receive a preset amount
of data from the Apple II/e/GS and just keep refreshing that data to a
vga monitor. The data would be a block 640 pixels x 400 screen
lines. I have already written the code for the fonts that can
reproduce a text screen, 80 col text screen, mousetext, and lo-res, hi-
res, dbl lo-res and dbl hi-res blocks can easily be reproduced on the
same 640 x 400 pixel screen. Each pixel would be 8 bits that points
to 1 of 256 colors so 640 x 400 = 25600 bytes would need to be sent
for the whole screen. This would fit in a 32 kb memory chip.
A 2048 byte video buffer (256 colors times 8 bytes per color, but only
6 are needed, 2 for red, 2 for green, 2 for blue for 65536 hues of
each color) to allow up to 256 colors on screen at the same time out
of a total of 16 million colors to select from, Since the colors
would really never be changed even in animation, (just the pointers to
the colors) then this buffer would only be needed to be loaded once at
startup of the computer.
And a 2 byte location for a memory address to store to 1 of the 25600
locations
A 2 kb font buffer would be needed in main or auxiliary RAM to allow
for 2 fonts. And the drivers I have written to display blocks of text
or blocks of colors take up less than 512 bytes per driver.
I realize that this means that all the screens would basically need
drivers to display the fonts and the fonts themselves would take up a
little bit of memory but then the expandability and font selection
would become basically unlimited. Even more mousetext characters
could be created.
In summation, all screens can be duplicated on the 640 x 400 pixel
screen with software drivers and fonts. The 2 kb color buffer only
needs to be updated at the very start when you turn on your computer.
The 32 kb display buffer is constantly refreshed to a vga monitor.
And a 2 byte memory address locator is accessed before sending data to
the 32 kb display buffer. And the data can be sent either by serial
port, usb (now that the cffa 3000 has usb), or slot card or any other
means to send data.
We have all this neat new hardware for the Apple II's but it is always
being limited to emulate what the Apple II used to support and not
being able to allow it to expand. For instance, I have written a
driver for the CFFA card that allows me to access 256 x 32 MB drives
right from the applesoft prompt. This gives me full access to an 8 GB
CFFA card. But I couldn't write this driver to use the firmware, due
to the firmware code only written to support 8 drives.
So can someone please build me a simple vga display card that displays
only one screen mode 640 x 480 and let me worry about displaying the
other modes with software drivers.
If you find fault with this post, don't blame me, because I'm just
rambling. -_-
Rob