Table of Contents

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Table of Contents

VGA Expansion for 128KB RAM, 2-board stack (without PS2 interface)

Features

Design Files

VGA Expansion for 128KB RAM, 2-board stack (without PS2 interface)

This is link to 2-board stack with PS2 interface

www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_vgaxram_2-boards_dsc_67670128.jpg

www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_vgaxram_2-boards_dsc_67680128.jpg

Features

Plug in existing 128KB RAM socket

25.175MHz pixel clock, 60Hz VGA

4K dual port RAM for video memory and font lookup tables

64-macrocell CPLD, EPM7064SLC44

64 columns, 48 rows of 8×8 pixel monochrome text

Video RAM can be written any time

Design Files

Schematic for RAM board

Schematic for dual-port VGA board

Gerber photoplot for RAM board

Gerber photoplot for dual-port VGA board