Given that I've just found a PDF copy of this book on the internet archive and it hasn't been taken down from there, I'm going to assume the following is okay. If there are any issues, I'm happy to delete this, or a mod can. Hopefully it's all good.
The errata page: http://www.charlespetzold.com/code/ which is pretty small. It seems to already be getting traffic (HN hug?) so you might need to reload it a couple times.
My first CPU was a Z80 running CP/M from two floppies. Monitor showed monochrome letters written in WordStar. Only survivor is moving the cursor usually word by word probably now hard coded in muscle memory. Writing this on a machine with no moving parts nor noise. Took 40 years to get from ASM to WASM, quite a ride.
I had one of those too. I remember Wordstar with fondness, which is why I now install the Joe editor on any new computer, and use Joe's jstar mode rather than nano.
Another thing I recall is spending $4K for a 40MB hard drive. Indeed, times have changed. :)
The accompanying article does a good job of putting CP/M in its historical context describing what it actually was. But other than nostalgia (and those who have sacrificed their eternal souls to WordStar), there isn't much of a reason to actually run CP/M itself. There's not a lot to see there - if you've ever used the MS Windows shell, imagine its Paleolithic ancestor.
CP/M source code (at least for 2.2 and earlier) was always pretty readily available because you often needed to make changes to it and the BIOS when adding new hardware. I remember when my Dad got a printer and serial card for his S100 bus system sometime around 1980. We spent hours making the necessary changes to CP/M and the BIOS so that it would work. We also had to wire up our own cable for the printer to make sure it matched the pin out for the serial card. It sure felt like an accomplishment when that darn printer actually worked.
I don't remember the source code being available. What was available was the BIOS (that you had to customize for your hardware), the boot loader to get stuff running, the CBIOS that did the disk reads and a cool program that let you patch your floppy drive parameters into your system.
I worked on a number of systems and getting the BIOS to work with new hardware was an amazing feeling. One of my last CP/M systems was the Zorba, it's claim to fame was the ability for it to emulate lots of different floppy formats. So you could move data from one format of a floppy to another. It was a huge win since the only other way to move data was via a serial connection.
The Zorba people would exchange formats as we figured out new ones.
The other cool thing "back in the day" was replacements for the Command Line Processor part of CP/M to allow some new commands to happen. Like Busybox but 40 years ago.
Yea, it was the last (and best) of the luggable systems. It came out as the first of the MSDos lap computers arrived. You can still get working ones on EBay for about $500.
That doesn't sound right to me. There were config utilities for that sort of thing and even if not, that kind of change would take a small amount of disassembly - you could do it by hand in a pinch. How would you even compile CP/M's 'primordial' PL/M source?
I was about to write CP/M is at least essential for enjoying The Hitchhiker's Guide to the Galaxy as Infocom text adventure (like I did on the Atari ST with CP/M emulator), but then I learnt it was available on most other OSes at the time as well, including on Atari/TOS native.
You should still be able to find Amstrad PCW and CPC systems in working order, although the 3" drives will probably need replacement rubber bands by now.
There are several virtual machines capable of running various versions of CP/M and a couple emulators of CP/M itself. (For example, https://github.com/jhallen/cpm )
