bsvplay(1) | hxtools | bsvplay(1) |
bsvplay — convert BASICA music data to PCM
bsvplay [-i part] [-q part] [-r rate] [file...] | aplay -f dat -c 1
bsvplay will convert BASICA binary music data to linear 16-bit raw PCM. Normally, you will be wanting to pipe it into a raw PCM player like aplay(1) to actually output it to a sound device. Be sure to lower the volume beforehand to avoid nasty surprises that come with square waves. By default, bsvplay will mix 1:1 square:sine waves to give a medium tone hardness.
Do note that the music data is embedded in BSV/EXE/COM files and needs to be manually located. It is usually very evident from a regular pattern in hexdumps.
The BASICA format is defined 6-byte tuples of divisor, duration and pause.
struct bsv_insn { uint16_t divisor; uint16_t duration; /* in ticks */ uint16_t af_pause; /* in ticks */ };
where divisor specifies the divisor value that it directly handed to the x86 PC speaker. The following formula holds:
frequency = 1193181 / divisor;
2008-02-06 | hxtools |