This is an old post, preserved for reference.
The products and services mentioned within are no longer available.
A few weeks ago, I wrote about building a prototype version of Bitfixer's Petdisk, an IEEE-488 disk drive for Commodore Pet computers, using an SD card for storage. Credit again to Bitfixer, the creator of the original Petdisk. This was the first stage of a plan to build my own Pet disk drive emulator, recreate what has already been done to prove the principle.
2022 Update: I have since designed a much nicer SD drive for a PET. The SD2PET is available from The Future Was 8 bit: SD2PET