Changes
/* Sound */
There is 1 sound source on 48K spectrums: it's beeper, and 2 sources of sound on 128K spectrums: beeper and AY.
Beeper sound is simple. The spectrum has a speaker which you can turn on/off through a I/O port on the Spectrum's ULA. To make different sounds, you turn it on and off at different rates, all under control of the CPU. Speaker sound is CPU intenstive because the timing is all done through the CPU and delay loops. The consequence on the Spectrum is that not many games have beeper music during the game, and those that do are often staccato like (e.g. Manic Miner) (the game takes some time to update, then some time for sound, and this repeats). If the sound was made for the Spectrum beeper, this would need to be converted to AY sound for the CPC, the result would not be exactly the same.
Sound written for the AY in the Spectrum can't be ported directly because it would be out of tune, this is down to the difference in master clock given to the AY (1.7Mhz on Spectrum, 1.0Mhz on Amstrad). The music would need to be altered. When this is done, the music is almost the same.
