Giulio / ceda-schematics - History

Schematics refactoring:

- New sheet reserved to video memory.
- Removed video memory parts inside video_generation.
- Removed video memory parts inside GPIO.
- Generic cleanup to keep all circuits inside each sheet.

Discovered WE and OE signals for video memories, plus others

parallel port, which is absolutely not a centronics port

Added FDC sheet (WIP), added partial parallel port inout

IO addressing space multiplexing and small IO description

Video memory concurrency

- bank7 selector to address video or attribute RAM
- found read and write data paths leading to video RAMs (F11, F12).
- video RAMs CS generation.