Emulation of BBC Micro mode7 (teletext) display on a Pi Pico.
This is an 'on the fly' rendition of the pixels from a 1Kbyte 40x25 character buffer in RAM.
This is primarily intended for the Electron Mode7 add-on, where the display created by the Pico is timed to match the syncs coming out of the Electron. However, for test purposes this repository also contains a sync generator that produces syncs intended to look like those generated by the Electron.
As it is intended to emulate a BBC Micro, the double-height logic does not automatically duplicate the 2nd line as a Teletext display would do: the user is meant to duplicate these manually (or can achieve special effects by not doing so).