Construction Of Filenames; Amsdos Headers - AMSTRAD cpc 6128 User Instruction

Construction of filenames
The filename is constructed from two parts with a • (dot) separating them. The first
part can be up to 8 characters long, and the second up to 3 characters long. Thus for
example: "R 0 I N T I ME. DE M" , " D I S C KIT 3 • CO M" ,and" D I S C • BA S" are all
legal filenames.
The second part of the filename is called the filetype. Filenames and filetypes can be
composed of a mixture of letters and numbers, but cannot have embedded spaces or
punctuation marks. Some common conventional filetypes are:
• <space>
.BAS
.BIN
.BAK
• COM
• SUB
J
Unspecified type. May be a data file created by an 0 PEN 0 U T
"<filename>" or BASIC program saved by AMSDOS using S A V E
" <filename>" , A style.
BASIC program saved by AMSDOS using S A V E "<filename>" or
S A V E "<filename>" , P or S A V E "<·filename> • BA S " , A styles.
Program or area of memory saved by AMSDOS using S AV E
"<filename>" , B , <binary parameters> style.
Old version of a file, where AMSDOS or a utility program has saved a
newer version of a file using an existing name. This allows the user to
back-track to the previous (BAcK-up) version ifrequired.
Command file.
CP/M
utility programs are all of this filetype .
Instruction file for the
CP/M
SUB M I T program .
AMSDOS headers
AMSDOS automatically S A V Es files with a suitable type identifier, so it is not
normally necessary to specify one unless you wish to override the defaults described
previously. BASIC program files, protected BASIC program files and binary files are
saved to the disc with a header record, so that the AMSDOS command:
LOAD
11
<filename,"
.... can recognise them and take the appropriate action.
If
the AMSDOS command
LOA D cannot find a header, it assumes that the file is a program in ASCII, i.e. plain
text.
AMSDOS
and CPIM Chapter 5 Page 3