
How to start with CP/M (2014) - federicoponzi
http://www.retrotechnology.com/dri/howto_cpm.html
======
fauria
Chapter 22 of " _Code: The Hidden Language of Computer Hardware and Software_
" uses CP/M to illustrate the inner workings of operating systems. I highly
recommend this book overall: [https://www.amazon.com/Code-Language-Computer-
Hardware-Softw...](https://www.amazon.com/Code-Language-Computer-Hardware-
Software/dp/0735611319)

~~~
exikyut
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.

\- archive.org PDF (9.2MB):
[https://ia801607.us.archive.org/7/items/CodeTheHiddenLanguag...](https://ia801607.us.archive.org/7/items/CodeTheHiddenLanguageOfComputerHardwareAndSoftware/CodeTheHiddenLanguageOfComputerHardwareAndSoftware.pdf)

\- The seemingly-legit-looking account of the uploader who put it on
archive.org:
[https://archive.org/details/@archiver849271](https://archive.org/details/@archiver849271)

\- The front page for the item on archive.org:
[https://archive.org/details/CodeTheHiddenLanguageOfComputerH...](https://archive.org/details/CodeTheHiddenLanguageOfComputerHardwareAndSoftware)

\- The directory the item is in:
[https://archive.org/download/CodeTheHiddenLanguageOfComputer...](https://archive.org/download/CodeTheHiddenLanguageOfComputerHardwareAndSoftware)

\--

I also found a 176MB scanned copy of the book as pure images:
[http://learning.caitlinmorris.net/sfpc/CharlesPetzold_Code.p...](http://learning.caitlinmorris.net/sfpc/CharlesPetzold_Code.pdf)

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noiv
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.

~~~
garyrob
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. :)

------
pvg
The source code of a few versions of CP/M was released a couple of years ago:

[http://www.computerhistory.org/atchm/early-digital-
research-...](http://www.computerhistory.org/atchm/early-digital-research-cpm-
source-code/)

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.

~~~
whyenot
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.

~~~
AstroJetson
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.

Now get off my lawn...

~~~
pvg
_One of my last CP /M systems was the Zorba_

That thing looks amazing as a machine, name and example of near-perfect market
mistiming. I'd never heard of it.

[https://en.wikipedia.org/wiki/Zorba_(computer)](https://en.wikipedia.org/wiki/Zorba_\(computer\))

most of the info seems to come from:

[http://www.zorba.z80.de](http://www.zorba.z80.de)

~~~
AstroJetson
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.

~~~
pvg
Out of curiosity, how did you end up with this beast at the time? According to
that German site, only a few thousand were made and sold.

------
kgilpin
It’s an intriguing subject for sure.

What’s missing to me here is “Why start with CP/M”?

~~~
mmjaa
Old computers never die - their users do!

------
pjmlp
Back in the day, a friend of mine had 3" disks for the ZX Spectrum +3 with
CP/M.

So this is a possible way to try out CP/M on real hardware, after finding one
in workable state.

~~~
UncleSlacky
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.

------
smacktoward
Can you virtualize it? Is there a virtualization solution available that
supports the Z80 architecture?

~~~
lholden
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](https://github.com/jhallen/cpm) )

