<> The 1002 HOST interface has a different address, register command <structure > though there are similarities wbeing both from WD. < <How do the above relate to the 8-bit IDE interface? The 8bit IDE looks like the 1002WA ISA 8bit controller. The 1002HDO host interface however does not. In the 8bit worlds there seems to be three different schemes. <> In any case adding a hard disk to kaypro requires utility software, an <> interface and BIOS. < <But if you have the TurboROM, you already have all of that with the <exception of the interface. How big a chore would it be to adapt the <WD1002/Host interface to the 8-bit IDE? If one could do that with <minimum difficulty, it could provide an easy 40mb of HD storage - a huge <amount on a CP/M machine. It's not easy. The host interface only allows for a few address lines and 8bit IDE is both scarce ands strange. For practical use and the difficulty of interface doing a 16bit IDE converter is more practical. The real problem is you no matter what will be writing a bios for the kaypro. People with the correct controller and MFM disk are already faced with things like the drive needs replacing and there is no formatter or partition utility if the drive is greater than 8mb. Check out TCJ #80, a 1002WXA or similar is easy as pie to interface to a 8bit bus (like the host adaptor port). and they are common enough as they were about the best thing for the XT class. It means using a MFM drive but, st225s and st251s are common and there are old 3.5" mfms that work good with those too. The bios problem remains though. Oh, 40mb would have to be sliced (partitioned) into 5 8Mb logical drives under cpm. I know as my SB180 and AmproLB both have 20 and 45mb drives. Under CPM even 5mb is a lot of space and a 1.44mb floppy is very roomy. The 781k format allows me to have all of my most common utilities and programming tools on one drive and work space on another. That good enough. Allison