The Commodore 64 requires a floating (transformer isolated) 9VAC supply as well as a 5V DC rail. Usually the 9V is done with big iron 60Hz transformers.
Can this be done using a Class-D amplifier, fed a suitable signal, driving a smaller high frequency transformer and a filtering network after the transformer?
Behold this NASA-level sketch:
The linear supply could be the 12VDC part of a PC power supply, or maybe even off-line.
The class-D could be anything from a one-chip solution to maybe discrete parts.
Now the question is, could using a smaller high frequency transformer work to provide the isolation? What kind of filter will I need? The red feedback part will be optically isolated and whatever is driving the 60Hz (or 50Hz) signal will be driven by the feedback loop.
What do you think?