Hello,
I'm attempting to modernize a datalogger by upgrading it from a 2.5 inch IDE hard drive to two compact flash cards in a 2.5 inch IDE adapter. My application is actually almost identical to the one found in this thread:
I have a 2.5 inch IDE to Compact Flash adapter from Addonics that has both a master and slave CF slot. When I populate both slots and plug it into an external drive enclosure, my XP PC detects and can interact with both cards. I believe the adapter works in a Cable Select mode, because the master's pin 28 is grounded and the slave's pin 28 is not connected to anything.
When I plug the populated adapter into my datalogger, I can only interact with the card in the master/Device 0 slot. When I try to read the slave card's status register I never get a DRDY (device ready) bit set.
My level of interaction is with the actual device registers, i.e. setting the number of sectors to write, giving an address to the sector/cylinder/head registers and then issuing a Write Sector command. The language I'm using is C, if it matters.
I've been using the ATA-ATAPI-5 specification to try to learn how to deal with two devices on the same IDE port, but it seems to imply that switching devices with the DEV bit in the device/head register should just work.
Is there anything special I need to do, perhaps at startup, to get the two cards to configure themselves properly?
Thanks much!
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