Table of Contents
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Table of Contents
Text-based VGA Display for RC2014
Introduction
VGARC is a text-based VGA display for RC2014. It is based on 8K of dual port RAM to communicate between RC2014 and video display.
Note: This page describes VGARC rev0.1 and prior prototype version. VGARC rev0.1 is now obsolete, replaced with VGARC rev1
Features
8K bytes of dual port RAM to simplify communication between Z80 and video display logic
State machine in Altera EPM7128S CPLD generates the video timings
8×8 pixel font
Font lookup table resides in the dual port RAM and is user programmable
Display 56 lines, 80 characters per line
Theory of Operation
Design Information
Software
TinyType Font, 8×8 font table
Conway Game of Life demonstration, Glider Gun on 56 x 80 screen
56 lines and 80 column text explaining the features of VGARC
Adding PS2 Keyboard
This section describes the modification to VGARC rev0.1 to add a PS2 keyboard.
CPLD equation for VGARC with PS2 keyboard
Engineering change for adding PS2 keyboard
Test software
VGARC Prototype
This prototype is based on RC2014 Rev 2 Prototype board which already has a EPM7128SQC100 connected to RC2014 bus with a number of user programmable test points. A 4Kx8 dual port RAM, IDT 71342, is breadboarded in the prototype area and connected to the EPM7128S. The CPLD outputs drive a HD15 connector's red and blue signals as well as the horizontal and vertical syncs.
Features
4K x 8 dual port RAM, IDT71342
State machine in EPM7128SQC100 generates video timing
640 x 480 display area, only 640 X 192 contains data due to RAM size limitation
8×8 pixel font
1K x 8 font table resides in the dual port RAM, user programmable
Theory of Operation
Design Information
EPM7128SQC100 CPLD equations
Software
Conway's game of life