Tom Stepleton is the guy running this project -- I lent him my Lisa for his work. Here's a wrap-up summary he sent me on the project just before he returned the system to me. -- Tony ---------------------- Here's a summary of what I've done. Addressing the unreliability of the wiring in the last attempt, I completely rewired the prototyping board and switched to a single 84-pin MAX 7000 chip and adapter instead of the Altera experimentation board used in class. Physically speaking, the circuit is complete. I was able to get the circuit to succesfully dupe the Lisa into believing that there really was a ProFile attached to the port. Unfortunately, there is really no interim step between that and full functionality. I came a long way, but I didn't make it. Here's what I managed to do: Linux side: On a machine borrowed from Professor Maxwell, I installed a secondary Linux kernel - version 2.4.0-test4 - which provides the latest facilities for manipulating the parallel port from a userland program (read more at http://people.redhat.com/twaugh/parport/html/parportguide.html). This is a really neat driver, incidentally, although it is still in development. Using this driver, I created MrProfile, a rudimentary ProFile emulation program. MrProfile currently responds to interrupts generated by the adapter, but all calls to read() extract zero bytes of data from the port. Whether this is due to poor programming, the driver, or a malprogrammed board is not yet clear. Adapter side: Using what I learned in making the program to fake a ProFile's existence, I completely reprogrammed the full-featured version of the adapter circuit. The philosophy behind the device's role has not changed much from before, but the code has been altered quite a bit to suit the whims of Altera. What happens: Activity on the Lisa side causes the adapter to alert the PC with an interrupt. The PC fails to read any data from the parallel port; the adapter sits waiting for something to happen, and the Lisa eventually times out. There are three reasons for why this is happening, now that poor connectivity has been ruled out (via multimeter): metastability, flaws in parallel port driver, and poor assumptions about the EPP parallel port standard. I don't think it's the first, because the problem is always the same. I feel it's about even odds between the second and third choices. The future: I'm not giving up, but the likelihood that I'll be able to put real work into it this fall is not all that great. Just in case the hardware has been programmed correctly, I'm taking the prototype board home to my two Lisas there (hope this is OK, Bruce), where I'll try getting it to work with an old Pentium 90. Even if the hardware is slightly faulty, the low-level programming capability of the parallel port driver suggests that I will be able to get around it. However, if I've made an error on the Lisa side, I'll be out of luck. I'll see what options I have and then make decisions. I'll also turn over all of my code to the folks on the Lisa and Lisa Emulator mailing lists at sunder.net and see if they can offer any tips.