Yeah :) I'm only an occasional contributor to the list, more of a lurker really since I was pretty busy this year. Well I promised a guy on the list some Unixy stuff that I had and have been gradually going through it and putting it on bitbucket but have not had time to write it all up yet. But I wanted to jump in and say something to the new people who joined the list owing to whatever was the recent media coverage we had. Welcome and all that. But IT ISN'T NECESSARY to have been around at the inception of Unix to get into it and to learn about the retro flavours, come up to speed in PDP-11 asm or learn about the old filesystems or whatever it is that floats your boat :) Personally when I discover something AWESOME I immediately want to take it apart and learn EVERYTHING about it. For me in the case of Unix, I quit my job in about 2005 and had about 3-6 months of downtime while considering my next moves, I had next to no money so I could not really leave the house, but I had a houseful of computers and a 33.6k modem so I set myself the task of learning about this mysterious Linux thing. I downloaded Slackware 4.0 onto a set of floppies and followed the Linux From Scratch instructions to build and bring up my own Linux flavour from that. This was very educational and it highlights the main point of my post which is you MUST GET YOUR HANDS DIRTY, reading ancient source code is fine but one doesn't retain much info unless one reads for a purpose (why the hell won't this RK05 boot my system etc). So anyway a lot of things still remained a bit mysterious after my LFS adventures since they are that way for historical reasons, and I found myself bringing up earlier Unices on simh to take a peek and joining this list etc. But as I said one does not retain much unless one has a purpose and probably the project that taught me the most was bringing up someone's hobby Unix V7 clone on a cash register motherboard from the equipment I used to sell in my day job. The software is called UZI (Unix Z80 implementation). I remembered waaay way back when I was pottering around with CP/M and enhancements like ZCPR3 I saw this mentioned in a newsgroup or similar, with a description that it runs Unix in 64k by loading the kernel in first 32k and a process in second 32k and uses "total swapping" i.e. it multitasks or implements child processes by writing the second 32k to a swapfile on floppy disk and loading it back in later. This sounded very intriguing and I wanted to try it out. So, years after reading this newsgroup post I obtained it and compiled it (using the IAR compiler we used for cash register development) for my cash register. Long story short the thing was soon utilizing various kinds of bank switched memory available in this cash register (which had a Z180 CPU and hence behaved like a Z80 with an MMU and other integrated peripherals) and had a network stack from Phil Karn's NOS, it had lots of communication ports for barcode scanners, printers, modem etc and I had them running SLIP and communicating with publicly available FTP servers, I used to use mirror.aarnet.edu.au for testing and my cash register could download small files. I became frustrated with the limitations of both UZI and NOS and decided to port 2.11BSD to the cash register as the next step, my goal was (a) make it cross compile from Linux to PDP-11, (b) check it can build an identical release tape through cross compilation, (c) port it to Z80 using my existing cross compiler. Well I don't think I got all the way through this ambitious programme before putting it aside and starting a new job but I sure as hell learned a lot about building PDP-11 Unix. The buildsystem is complicated and contains its share of hacks, but overall much simpler than something like gnu's configure/make or cmake or etc. Although I was not around for early Unix (was probably a 10yr old taking apart an Apple II and trying to learn 6502 code without the benefit of an assembler in 1985 when stuff like SVR4 was popular) I probably know as much about its internals and development environment as many people here, due to having got my hands dirty, albeit 30 years later. In fact I FEEL LIKE I WAS THERE. So my suggestion to newbies is, get your simh on, and tackle some interesting project such as reconstructing an early source for something from the fragmentary surviving pieces, backporting some useful tool to an earlier Unix, or whatever. Just get your hands dirty and it will be an infinitely rewarding experience. Because Unix is AWESOME. Retrocomputing is AWESOME. Simulators are AWESOME. :) cheers, Nick On Dec 25, 2016 2:17 PM, "Larry McVoy" <lm(a)mcvoy.com> wrote: