The free sample is good reading and makes me want to read more. However Amazon has only made the book available as a free Kindle download (to Kindle devices) or as a $$$ paperback. As author, can you ask Amazon to make the book available as a downloadable PDF?

Author here.

I appreciate the feedback and I'm glad you like it.

As far as I know, it is not possible to sell PDF through Amazon KDP. As a promotion, Kindle was free for 5 days.

I will perhaps publish free of charge in one year or two from now.

I remember BBSes as having much more polite conversations than you find these days on social media, too!

Does your aunt or f-i-l really need to know? I know older nerds who only use a smartphone for texts and voice calls, and who can't be bothered wasting time on social media. So far (anyway) "essential" apps like banking ones and government ones and "remotely check your home security cameras/solar panel output/etc" ones seem to be paralleled on the Web and accessible through a browser.

See https://www.datafix.com.au/cookbook/ and https://www.datafix.com.au/BASHing/

"The look on the faces of a fresh crop of 20-something developers"... My equivalent is doing a data reformat or analysis on a big dataset that someone has been struggling with in (please excuse my language) Excel. The data owner's eyes widen and they say something like "Wow! That's so fast and simple! How come I never heard of this stuff?"

Good question about "Old". In Australia there's at least one well-defined cut-off: 75 years. If you're 75 or older: - when you die your death isn't classed as "premature", and demographers don't assign you any "potential years of life lost" - you're no longer invited to have screening for bowel, breast or cervical cancer screening (invites go to 50-74 year-olds)

Dinosaurs of UNIX?

VM/CMS still exists in some form in the IBM world, I think, but it would be hard to find a device that still runs RSTS/E.

I haven't used Windows since 2007 and don't miss it.

Yeah, IBM mainframes still use VM and run CMS and other OS inside the VM. IBM was slow to the timesharing party, their plan to make "one OS" for the 360 failed utterly, and some academics got the idea for VM that became the real OS strategy for the 370 and future machines, I saw a Youtube video where people demo VM in 1975

https://www.youtube.com/watch?v=Mo2q7d5dJgg

personally I remember using it on an IBM 3090 at the New Hampshire Insurance company in the late 1980s when I was in the computer explorers.

Sometime I think about setting up a PDP-11 emulator and running RSTS/E in it for old times sake.

I also really enjoyed running OS/9 on a TRS-80 color computer, which was a really cheap machine with serious limitations (32 character display) but I had mine (I think a Coco 3 at that point) hooked up to a TRS-80 Model 100 and a DEC printing terminal so I had a Unix-like experience on three consoles, my impression was that OS/9 was a better OS than anything mainstream on IBM PC hardware at the time.