View Full Version : New user of CP/M on a Micro 8800

April 3rd, 2012, 06:24 AM
I've built from a kit an Altair Micro8800 with CP/M capability. Using information available on the internet I'm attempting to learn how to use commands. The following questions are really dumb (sorry about that). The reason I'm asking is I can't seem to make most of them work. OK, here is what I'd like to know. How to load and run a program. Simple isn't it. Yup. I assume:

Load (program name) (I can't get to work)
Run (program name) ( can't get it to work)

Dir: (drive designator such as "b") (correct?)

Name if you would other commands that a new user would use.

Thank you

April 3rd, 2012, 07:47 AM
I do not know how the Micro 8800 gets its program files from the PC, but if you had a normal CP/M system with its own disk drive(s), you would see, after the CP/M has loaded, the A> prompt.


The system is now waiting for a command, if you wanted to run a program you would type in the name of the program (or command) you wanted to run.


CP/M would load and execute wordstar, if it is on the disk.

B> would tell CP/M to use drive B as the "default" drive.

The "built in" commands are DIR x, ERA x, TYPE x, REN x, SAVE nn x:filename,typ, and USER nn
Hope this helps.

April 3rd, 2012, 08:15 AM
No, entering B: followed by a return would set B: to the default drive.

It's good practice to talk about drive names using a trailing colon. Over at Gaby's CP/M web site at http://z80.de/ecpm.htm, there's a treasure trove of CP/M documentation, including the very slim user's manual.

Edit: I'll add a couple more items that will get you going. 8-bit CP/M has only one kind of executable file: that which ends in .COM. So, the very simple-minded operating system assumes that if you type in a word at the prompt, that it should go looking for a file with that name, ending in a .COM "extension", if the word is not one of the "built in" commands noted above.

If you have more than one drive, you must either be "logged in" to the drive containing the command (i.e. it's your current default drive) or you've specified the letter of the drive containing the .COM file explicitly.

For example, suppose the A: drive is your default and there's a file called WS.COM on that drive. Entering the command WS will cause that file to be loaded and executed. (LOAD is a very different command; it creates an executable file from an Intel-format hex file.)

Now, suppose the WS file is located on the B: drive, and you're still defaulting to the A: drive. You can execute that file by entering the command B:WS.

It's pretty simple, really--how much complexity can one pack into less than 20KB of code?

April 3rd, 2012, 08:22 AM
Sorry, it's been years since I actually used CP/M, I was working from memory and a quick glance at a CP/M book.

April 4th, 2012, 08:20 AM
OK, I've used your suggestions and have been able to get things going! Thank you for your input!