Posted By
TLC
on 2010-10-18
08:58:56
|  Re: SID-card scheme?
As siz said: the SID needs something not trivial to provide, given the constraints implied by the cartridge port. The cartridge port provides 5V supply only. Both the old and new SIDs require special power supply voltages above the usual 5V digital supply voltage (old: 12V, new: 9V). If you only have 5V DC as power source (no AC voltages etc.), then the only possibility is to use some switching mode step-up converter circuitry, to come up with the required higher voltage level supply. Back then, this has not been easy to do, very few people knew these things in practice (...which seems to show Solder's superiority again, at the same time... he already knew the solution and the TL497 chip (the chip he used as base of the small SMPS on his SID card, that provides the 9V supply of the SID) back in 1992... ). Today it's a lot more common to see solutions like that (in fact most of today's handheld devices contain at least one of such step-down or step-up switching mode voltage converter + regulator).
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