Experiments in IDE-CF Adapters

The original goal of these experiments was to provide a reliable storage solution for older computers which usually weren't used much. PATA drives are still available, but are essentially obsolete. Older machines with PATA drives are having drive failures and the options were replace with a new PATA drive or look into CF card use.

IDE to CF adapters are pretty straightforward and are more or less straight through adapters to CF, so the limiting factor in performance should be your CF card. The flash in CF cards have a limited number of write cycles, so the CF cards will fail eventually. However, the intended use here is for machines infrequently used, so this is not a problem for my particular use case. Additionally, flash card sizes are small enough that imaging them and saving off to a modern storage solution is trivial, as is restoring them.

General Comments

Before getting into the details of card use, a few comments are in order. After using CF cards in a number of machines now, I would not recommend them for regular use. On essentially every machine I've tried with different brands of adapters and cards, I have noticed stuttering. The disk access will apparently hang for a second or so, with no apparent progress. The best explaination I have heard for this is the card's wear leveling is kicking in. This is usually a minor annoyance with more robust IDE controllers and drivers, however some systems don't deal so well with the device "locking up" for short periods.

SD-CF adapters

SD to CF adapters such as this weren't designed to be a full ATA device, but for use in a simple card reader. In my experience they do not play well with other IDE devices, especially another master/slave on the same bus, but even with devices on other busses on the same controller. I have had luck using one in a which only had one controller with one bus and this was the only device. Also, these are the larger type II formfactor, which is thicker/taller. Normally this is not an issue as the whole assembly including IDE adapter is much smaller than a disk drive. However, keep this in mind as some IDE-CF adapters enclose the entire CF card and may prevent these SD-CF adapters from fitting

IDE-CF adapters

I've used several different types of IDE-CF adapters at this point, including the Syba SY-IDE2CF-NB25 which is a 2.5" 44pin adapter, a 40pin male connector Syba adapter, and several generic brands purchased off ebay. Since the adapter is essentially a passthrough device, I haven't seen any differences in behavior between the different adapters. However, when purchasing adapters, there are a lot of choices. 40pin adapters tend to use female connectors for plugging straight into a motherboard connector. This precludes the use of a second device on the bus (like an optical drive). This can also have mechanical problems if there is insufficient room around the motherboard IDE connector. 40pin male connectors allow the use of a traditional IDE cable, and are readily available but somewhat less common than the female connectors. 40pin adapters require a power source, and due to space constraints most use a floppy power connector. Keep this in mind, as floppy power connectors on power supplies are becoming less common and often are not the desired length. Some 40pin adapters allow powering off the 40pin PATA connector. I personally have not had luck doing this and always require an power connector.

All IDE-CF adapters I've used have come with a jumper for setting both master/slave/cable select and most allow setting the CF card voltage (3.3V or 5V). Nearly all modern cards take both, however I have run into some older cards that only operate at 5V. 3.3V is safer to start with, and if you run into issues, you can bump it up to 5V


SCSI to IDE Adapters with IDE to CF

Experiments with the R-IDSC-E/R SCSI to IDE adapter are documented here, but the summary is: most cards work pretty well.

CF Cards

I have also not run into problems with different manufacturer/model CF cards, with the exception of the SD-CF adapter mentioned earlier. For this reason I am omitting the CF card size/type from the chart. If a difference happens to crop up in the future I will update the table to note it. For posterity, my testing has been with several Kingston (both unlabeled and 133x) and a SanDisk Ultra II card. Sizes ranged from 4GB to 8GB

An additional side note on CF cards. Some IDE controllers require UDMA to function properly. Most CF cards (none of the ones I've tested with) support UDMA. Some higher end ~300x CF cards do support UDMA and will likely have better compatibility results than what I've tried. They're also much faster.

Test Results

Sony Vaio PCG-R505ESYSuccessfully using SD-CF adapter
Sony Vaio PCG-505trNBIOS failed to recognize any adapter or card
Intel 910 motherboardYBoots fine, problems on both busses using SD-CF adapter
Beige G3 desktopYBoots fine, using OS9 and 10.2
PismoYBoots fine, using 10.4
SEYBoots fine, using System 7.1. This is using an R-IDSC-E SCSI to IDE converter
ClassicYBoots fine, using System 7.1. This is using an R-IDSC-E SCSI to IDE converter
PowerMac 8500YBoots fine, using OS9.1. This is using an R-IDSC-E SCSI to IDE converter
Macintosh IIxYBoots fine, using System 6.0.8, 7.0.1, 7.1, A/UX 2.0, 3.0.1, 3.1. This is using an R-IDSC-E SCSI to IDE converter
Performa 630CD-Sees the card using Drive Setup, can install, but hangs when booting with it. This may be related to the CF card not supporting DMA
Performa 6400-Sees the card using Drive Setup, hangs during install