@Dbug, of course I can...
The project, an opensource digital tape player replacement:
using an arduino, selecting and playing a tap file from sd with buttons sending audio signal to a jack output at a reasonable cheap cost. Buttons are play/stop, up/down, and menu. Look for tapuino (c64) and tzxduino (zx) for additional hw information you are right, it plays file on the fly, you need 5v from microusb power supply. I'm testing speed up limits so tap2f16 will be focused to nax speed limit for the libraries used by this device , I need a little break now. Direct recording (tzx id15) conversion was made before getting good speed improvement before native tap loading. Due to limitations mentioned, I will focus on max speed improvement in next release.
This project combines and enhance the msx cas/tsx, zx81, zx spectrum, Amstrad, acorn bbc/electron with oric. Until now, Oric audio was posible converting it first to another format. Limitations of the project, not reaching 22 Khz for audio. For zx, 6000 bauds working.
Maxduino is full compatible with TZXduino and CASduino, it combines both of them in the same limited space. You can flash back and forward your firmware with Arduino IDE (version 1.8.4 recommended) without harming your device. Remember to configure your screen options and features in userconfig.h. Forgot some parameters? Reflash it again.. Userconfig.h allows to tune your supported capacity, activate/deactivate features until you fill confortable in your limited arduino space.
Nowdays inspiration goes beyond, retrofitting arduino nano chip with new arduino nano every (chip ATMega4809 instead of ATMega328) is posible to add more capacity and bring new features (see youtube videos). Also new board arduino mega with extra capacity will be supported hopefully in next version thanks to maxduino team member merlinkv. New supporting platforms on the way.
The key point is you must select your platform+port in your arduino ide, your sketch will compile according to this configuration.
How do I then update a TZXDuino with this update?
Back to basics ... Download your arduino ide and libraries, check this blog:
https://tzxduino.wordpress.com/tzxduino/
Hope this put you on the road..
Rafa