will tell you that on a Research Machine 380Z you have to type
B. CP/M is loaded into the top part of the computers RAM and
when it 15 run it clears the screen and prints a system prompt.
In some versions 1t also prints a system message such as “48K
CP/M” before the prompt. The prompt looks like this:
This means that drive A is active and that CP/M is waiting for
Nas-Sys uses single letter commands and there are quite a
lot of them. CP/M is far larger than Nas-Sys and more complex
but has suprisingly few commands. These are usually referred to
as the “built-in” commands and there are 5 of them in version
1.4 of CP/M. Strictly speaking there are more commands than this
if you count the instructions that can be given to the system by
pressing the Control key 1n combination with some of the
alphabetical keys. The built-in commands are DIR, ERA, REN.
SAVE and TYPE. To issue a command to CP/M you would type one of
these commands usually followed by the name of a file, sometimes
with parameters as well and press return. Before I go into
detail about what the commands accomplish, it is first necessary
to say something about file names, as these will not be familiar
to the majority of Nascom users. Some machines use filenames as
part of their tape handling system and one sometimes sees
programs which enable the Nascom to put a name at the start of a
tape and search for the name when the tape is loaded.
CP/M file names have two parts which are seperated by a full
stop. The first part is the name of the file and the second
part, called the extension, is used to show the type of file
referred to. For example, a file called HELLO.BAS would almost
certainly be a BASIC program called “HELLO”. 1f a command is to
refer to more than one file, an ambiguous file name can be
specified using the characters “?” and “#”. The question mark
represents any single character that could appear in the file
name and the star represents up to eight characters in the file
name or up to three characters in the file type. For example.
the ambiguous file name MARVIN. would match with the files
MARVIN.BAS and MARVIN. INT as well as MARVIN.COM, and %.BAa? would
match with HELLO.BAS, HELLO.BAK, DATA.BAD and many more. To put
it another way, %.# means the same as 22727277. 27?
The command ERA, not suprisingly, is used to erase files
from the disc you are working on. If you type ERA *.BAS all the
files with that extension will vanish from the disc. If you
type ERA HELLO.BAS only the file with that name will be erased
And if you type ERA #.% , CP/M will ask you 1# you are joking
because that would erase all the files on that disc
Before you start to erase things it is necessary to know
what is actually there. The command DIR enables you to do this.
If you type it on its own, CP/M will list all the files on the
disc. If you follow the DIR with an ambiguous file name, al
the file names that match will be listed
The name of a file can be changed using the REN command. To
change the name of the file HELLO.BAS, for example, you might
type REN GREETING. BAS=HELLO.BAS. The new name 15 always first
and the old name last.