As of March 2017, Persistor recommends swissbit C-300 series memory cards for sizes up to and including 1GB and C-320 series memory cards for values of 2GB and up.
These cards can usually be purchased at Digikey or Mouser.
Please be aware that many memory cards may appear to work in a Persistor product but may have qualities that can cause problems. Such qualities might be high current drain, bus conflict, time to ready, wear leveling, type of flash and non-standard formatting. Also please be aware that the Persistor CF2 can only recognize volumes up to 128GB (137,438,953,472 bytes). Follow this link to more information about file size limits.
Always format your memory card with PicoDOS.
CompactFlash Recommendation History
Prior to April 2005, Persistor recommended SanDisk OEM cards. There were several changes of labeling and part numbers
When Sandisk discontinued OEM cards about April 2005, Persistor began to recommend Silicon Systems SiliconDrive memory cards and changed the value of pull-ups on the data bus and updated PicoDOS to minimize current drain. This document describes those changes.
In 2007, Persistor identified two rare but possible corruption problems when using power-cycling sleep modes. One problem was specifically shown to exist in 3005 series SiliconDrive memory cards and not demonstrable in 3500 series cards. The second problem required moving to PicoDOS 4.03 (CF1 or CF2) or modifying your program with a simple timing change. At this time Persistor began to recommend Silicon Systems 3500 series cards This document describes these two failure modes and the change to 3500 series cards.
From 2007 until their EOL, Persistor recommended Western Digital 3500 series memory cards. Here is the notice of the change from 3500 series to 4500 and 4600 cards.
In August 2012 a hardware change was made to CF1s to make them compatible with memory cards produced to comply with the latest CompactFlash specification. This document describes that change to the CF1 only.
From July 2011 until their EOL, Persistor recommended Western Digital 4500 and 4600 series memory cards. Here is the notice of the change from 4500 and 4600 cards to swissbit C-300 and C-320 series memory cards.