RISCy endian

B’dum tish 😀


The Jag coding continues, I finally cracked my audio issue last night.  Sounding somewhat like white noise at least was pleasing in that I was getting noise out of the PWM DACs, however it wasn’t the noise I was .. erm.. looking for..  Much faffing and nothing, no change.  However whilst confirming the sample properties for the umpteenth time it struck me (no not the sample!).. ENDIANESS!  Those pesky chaps at Intel went and picked the wrong one! (Motorola having picked the right one, so sayeth me).. and as the sample was 16bit, this all made sense!  A quick bit of byte swapping fun and bingo, audible sound!

So what has this to do with RISCs? 68K isn’t one for starters, but the DSP is.  After eventually spotting a few more rookie errors and clearing the correct latches I have the DSP happily playing a sample from RAM all on it’s billy.  Nothing amazing I know, but step one in me both learning RISC assembly and writing my own multichannel sound routines and tracker.

Once again quite pleased with myself, so thought I should have a scribble here :)… now, back to the code.