Yes, I'm afraid that it is impossible to use the 500W Hercules black gloss, silent and as small as an original A500/600/1200 PSU to make a 25A +5V (with equivalent 12V Amps) replacement that with the addition of a simple RadioShack on-off switch between the green and a black wire to make a PSU that will handle even the most expanded demands of one of the above computers, like the three I have done by adding one of the DIN 5-pin connectors I bought from you.
Will the horror never end?