Sinclair ZX Spectrum Loading Music ... "Manic Water Music" (Manic Miner)

Описание: Loading the last third of the screen display on a ZX Spectrum, with a graphic display of water... that somehow plays a familiar tune within its screeching!

For those technically inclined:
I first made a program in assembly language that writes an arbitrary run of bit (either on-or-off) into memory. So given 3,4 it'll write '11100001 11000011 10000111 00001110 00011100' etc

It also had a counter to determine how long each bit would last when loading (with 1's lasting twice as long as 0's).

Then wrote, what I suppose you'd call a "memory loader routine", where a Data string [eg (3,4) (1,6) (2,2) (14,1)] could be written sequentially into memory with each step lasting the same duration upon loading.

Then I did lots of permutations of bit lengths, recorded the output when they loaded, and by ear noted down which ones were closest to Actual Notes.

Then put the data for the notes I wanted into my "memory loader". For this example I just used the bottom third of the screen display (2048 bytes, starting at memory location 20480).
(The ZX Spectrum screen display starts at 16384 and has 6144 bytes of bitmap display, then 768 bytes of colour attribute information - making 6912 bytes in total)

So - loads of effort for very very little reward. But an interesting technical exercise nonetheless.