[TUHS] Porting Unix v6 to i386

Hi, The last few weeks I've thought a lot about porting Unix v6 to the PC. Here are my "results": 1. If you really want to do it, don't do it from scratch. Porting Unix 1:1 maybe the usual way but integrating your code step by step into another Unix or Unix-a-like operating system will surely become much easier as you can test the result in every stage of development. Another benefit is of course that with a little bit of luck you don't have to rewrite all the machine dependent stuff as it might already exist in the other os. If you want to do things this way ELKS (the Linux kernel subset for the 8088) might be a good candidate as it is very simple and by this very easy to understand. Also there is a big Linux/ELKS community which might help you with some problems. 2.Another question is if it is really necessary to port when so many good emulators for the PDP11 exist. Of course a ported Unix is faster than one running on a simulator but is fastness really so important in times where multi-processor machines exist that make your 1.5Ghz machine look like a fool? Also wouldn't a user who needs a professional fast Unix (or a-like) take the newest Linux or one of the BSDs instead of Unix v6? The main reason for porting is from my point of view to get access to the i86's hardware. But for reaching this aim a port isn't necessary. You can either develop the emulated machine further so that it has additional devices (and interupts, etc. for them) or you can try to give the os on the emulated machine direct access to the real machine. This may sound a little bit strange and unusual but will save much code in the emulator as you don't have to code for each device twice (one time in the emulator and one time in the os). Of course the os you're running your emulator on must give you the chance to get direct access to the real hardware, but I found a DOS port from Bob Supniks J-11 emulator so that is not a real problem. Currently I'm working on the latter idea (on the emulator which gives you direct access to the hardware), but in fact I haven't written a line of code yet as I'm still searching for the best way to integrate the interesting parts of PC's memory into PDP11's memory. The idea is to put the interesting parts of PC's memory behind PDP11's memory and to change some lines in Unix that for example malloc doesn't get the idea to give this pieces of memory away to user programs. Putting the PC's memory before the memory space of the PDP11 would as far as I can see make more changes especially in the code relevant for booting necessary. Other things like for example PC's interupts will surely make much less trouble. Suggestions, ideas, opinions, etc. are very welcome. If someone feels the urge to help me with this project it would be very kind if he would let me know ;-) BTW: if someone has patches to the v6 or ported programs it would be very kind if he would send them to me. If I get enough stuff I'll make something like a new Unix v6 distribution. Sven