ATLAS VIDEO MODE DEMO

Demo of the video card module of my Atlas Computer, a Z80 DIY computer currently running at 10MHz.
Supports 4 video modes
320x200x4 (16 colors) Text & Graphics
640x400x1 (2 colors) Text & Graphics
I am using a Renesas (IDT) 32K x 8 Dual-Port RAM and a Tang Nano FPGA.
All info will be made available on the website when i finalize my design.
Current progress is always available on Github.
newbrainemu.eu...
github.com/cde...

[@gasparinizuzzurro6306]

It is an interesting project. can briefly explain how vram is "seen" from the cpu perspective? is seen as a memory paged block, is shared in the z80 space? Do the CPU be slowed down or blocked when it does access the vram during screen build up ? ( i think no, because of dual ported ram)

[@CDESP072]

Cpu has access through the MMU so the delay is just the page in and out. No delays as it is dual port so no blocking.

[@gasparinizuzzurro6306]

@@CDESP072 thx for explanations

[@gasparinizuzzurro6306]

Why it's so slow in gfx ? it should not be if the CPU is running @10Mhz and filling 32KVRam

[@CDESP072]

At that time my storage device was an arduino nano communicating with z80 via rs232.

[@gasparinizuzzurro6306]

@@CDESP072 baud rate?

[@CDESP072]

@@gasparinizuzzurro6306 i think 38400bps