sound recorder on flash using atmel application note 335

I am going to record a second or so of voice and playback much slower.
Custom sound chips are nice and simple, yes, however I want to invert the PCM values on playback etc so need to and will enjoy getting an Arduino to do something useful!
I followed up on other forum help on the ‘record and playback on arduino’ theme - took stock and got the AVR335 Application Note and flash chip. I was hoping there wouldn’t be too much code to adapt for the IDE to compile. Alas, not so straightforward it seems.
Verify errors aplenty.

dataflash.h (2.44 KB)

dataflash.h (2.44 KB)

sound_system2.c (10.8 KB)

Verify errors aplenty

But only snippets of code.

Good luck.