Re: [TUHS] Unix V6: Assembler Listings

below... On Thu, Jun 11, 2020 at 9:04 AM Paul Riley &lt;pdr0663(a)icloud.com&gt; wrote: Yes - the AT&T syntax was much simpler/less sugar than the DEC assembler. But the differences are pretty easy to see. IIRC that assembler generates DEC style linker objects and there is a companion linker that can create DEC binary objects (*i.e.* 'obj' files) as well as traditional UNIX a.out format. The entire tool suite was created originally to move code from RT-11 to UNIX at Harvard and passed around the nascent USENIX community. IIRC that version was forked from a BSD 2.x/NetBSD source repository and folks were adding some fields/features in the DEC obj format that RSX supported that RT-11 did not. Go hunting and see what you find. My memory was that with the BSD 2.x project, somebody added a DEC obj to UNIX binary (a.out) converter tool, so that you could use ld(1) instead of using the DEC style linker that had been included in the original. It has been >>years<< since I was really familiar with any of this stuff. A question about it came up last fall/winter on the simh mailing listing, which is where I found the the URL. FWIW: I offered the modern port, assuming you might want to run some of it as a cross-systems on a newer OS with a modern compiler. But if you are content running this on V6, then you might just want to go back to the original. As I said, my memory is that's in the original USENIX Harvard tape. All that should be Warner's archives if not other places on the Internet. Just remember that a big problem with the original code is that it will be written in pre-'White Book' C (that many of us learned years ago - not even ANSI of Second edition - this used Lesk's portable C library etc.). It sometimes looks a little strange to modern eyes. Also if you go looking, IIRC, someone at Harvard ported the DEC Macro RT-11 library to UNIX v6. In the late 1970s, I remember tjk, Danny Klein, Tron McConnell and I, plus some of the folks over in the bio-med group (whose names I have forgotten) had to a number assembler codes that had been written for the earlier RT-11 systems to Unix for one of the projects we had. Some of it got re-written in C, but I do remember we managed to use the Harvard assembler somehow for parts of it. If my memory is correct, early VMS and messing with BLISS compatibility could have been mixed up in the project somehow, but I've long forgotten the details of what we were doing at the time. Have fun.