TRS80 model 4

The TRS80 model 4 has its internal speaker hanging off bit 0 on port #90.  Runs at 4Mhz; far better working with than the more challenging model 1 @ 1.7Mhz.
Hoping that I have done some justice to Shiru, Utz, Tim and the few others of their engines & tunes that are up and running .

https://github.com/bushy555/TRS80-model … AL_SPEAKER

As a quick example: SquatM\Lets Go : https://youtu.be/a37N2d97Xck