Added configuration setting VDAEMU_SERKBD which can be used to specify any serial unit # to be used as the keyboard for the video terminal. Default value is $FF which means to use the default hardware keyboard. All other values mean that terminal input is to come from corresponding serial unit #.
Also a couple more tweaks to the p-System boot volume.
Added a generic routine in HBIOS to play a beep sound on the first available sound device. Implemented the beep in the ANSI and TTY terminal emulators.