Re: Apple II VGA Video Generator Card Project

[aiiadict@gmail.com]

>So, what block of the vga card diagram are you going to write in a hdl?
>
>the dual ported ram ?

8k RAM with two data/address busses, a select
line chooses which of these two to actually control
the RAM

>the softswitches state latch ?

watch for accesses to $C000, and keep a copy
of what state the Apple II video circuits are currently
in.

>the address scanner ?

scan through the dual port RAM in the display
order, and send to the p&s generator

>the pixel & sync generator ?

generate VGA signal, proper pixel color,
placement on screen, stretch pixel to screen,

My attempted definitions are above...

Define each in greater detail, and I'll pick one or more.

We also have to take into account Text mode, and have
the character ROM (custom?) in the circuit.  we can either
use the APple character ROM, or design our own bitmap
that displays nice on the increased resolution screen.


Rich