This is an old post, preserved for reference.
The products and services mentioned within are no longer available.
This post has been left for historic information. The PET microSD is no longer in production. The replacement SD2PET is available now, more information on the pre-order page.
I've designed some new revisions of the PET microSD, taking onboard some feedback from the original version. One user had a problem with power supply. The PET's 5V rail is a little overloaded on earlier boards at best, and sometimes when the capacitors dry up a bit the rails can take a little long to rise to the appropriate levels. Upping the brownout protection on the microcontroller helped in this case. I've never been happy tapping the 5V rail, so I've added a switch mode 5V regulator to the board, so this can now run on anything from 7V to 22V, which with come from the main reservoir capacitor, which is around 9V DC, or the 18V rail which feeds the 12V regulator.
the new PET microSD range.
2022 Update: I have since designed a much nicer SD drive for a PET. The SD2PET is available from The Future Was 8 bit