This circuit provides a 5 V negative output with a maximum current of 1 A. The circuit is from the 1993 Linear Technology Applications and uses common components at the time.
Today we have more compact solutions. This is from a Radio Electronics magazine from October 1990....
This circuit is from an 80's documentation, making use of PUTs that are not currently common...
This circuit multiplies the input voltage by 3 and can work with up to 12 V input. The current is a few...