I've seen lots of interesting snippets about how one might do this, but I'm curious ... Has anybody actually DONE this? Some of the search results I've seen when looking for "compact flash" don't even contain those words. Others are really just a "cat fight" over one thing or another and not terribly relevant.

I'm curious what hardware has been used in fabricating a functional prototype of an 803x (in the 40 or 44 pin DIP or PLCC). along with an external RAM and ROM along with a CF module. What the rest of the hardware does isn't terribly important, but I certainly am curious how the CF module was adapted to a prototype. Was it done on a PCB?

I'm trying to avoid that.

I'm considering building a device for a colleague at the university, so he can substitute a CF module for an old, Old, OLD MFM disk drive from a DEC machine that he wants to continue to use in his work. The age of the drives is beginning to trouble him, however. I can capture the CHS data on which the interface control logic is based from the MFM data stream and subsequently buffer the sector data. I can also do the reverse, both in hardware, of course, and I can extract the timing from the controller data stream. However, as far as attaching a CF module to a wirewrap card, I'm having difficulty deciding how I want to do that. The current plan is to modify the 40-pin connector on one of those IDE to CF adapters such that it can be plugged into the wire-wrap card directly and connected to the rest of the logic, etc. Since the device has to emulate an ST506/412-class fixed disk drive, the signals will be limited to what the DEC controller uses to communicate with its drives.

Since I'm not in love with developing PCB's (I usually farm that out.) and since there will probably never be more than two of these devices built, I seen no better way than wire-wrap for this sort of project. The mechanical interface to the CF module is the only real "crux" I've encountered.

Have any of you guys actually done this 805x-to-CF interface, and how did you manage the physical interface? What "interesting" obstacles did you encounter? How did the firmware interface to the CF work out?

What kind of worst-case timing issues did you encounter? That worries me a little, since the host controller is designed around the mechanical operation of the HDD, and, since the CF module does its own load-leveling in local firmware, I fear it might take longer than the controller will tolerate in order to complete a write, so how I handle the "ready" timing will possibly be critical.

Any words of wisdom?

RE