v0.4

Fixes many bugs and adds additional features.

New Features

• DIP Z80 instead of PLCC Z80, for cost reduction;
• Sega Genesis controller support. Also for cost reduction, because: I bet you have a Genesis controller, but not an SMS or SG-1000 controller lying around;
• Debounce circuit on pause button;
• Trim pot for fine tuning TMS9918 input clock

Fixed Bugs

• /JOY_SEL was missing from edge, preventing keyboard from seizing control of the joystick decoding;
• Page-switching logic LOAD signal is now properly inverted when selected;
• Overpour onto expansion edge fixed;
• Missing silkscreens for some parts fixed