The DevPPN system organizes disk space into physical devices, logical units, and a pair of octal numbers referred to as the "PPN". Within this structure are the files, which consist of a one-to-six character name and a one-to-three character extension. The characters used in filenames are from the "RAD50" set, which consists of 0-9, A-Z, and $. No part of the filespec is case sensitive. For example, the following are equivalent:
DSK0:COPY.LIT[1,4]
dsk0:copy.lit[1,4]
Dsk0:Copy.Lit[1,4]
In these examples, the physical device is DSK, the logical unit is 0, and the PPN is [1,4]. The file name is COPY and the extension is LIT.
Under DevPPN, a logical unit was essentially a partition within a physical disk device, more or less equivalent to a drive letter under Windows. Within each logical unit, there were individual directories identified by a pair of octal numbers (each ranging from 0-377) referred to as a "PPN" (Project, Program Number). Individual directories (i.e. a PPN within a logical unit within a physical unit) could also be assigned aliases, called ERSATZ devices, which have the syntax of device names. This is similar to the situation under Windows where a drive letter can be mapped to another directory. These ERSATZ devices are defined in a text file DSK0:ERSATZ.INI[1,4]. You can add your own (each one consisting of up to six "RAD50" characters starting with an alphabetic character). In addition, the standard ERSATZ.INI defines ERSATZ device names for a collection of PPNs on DSK0: which are considered the "system accounts" and which are listed in the following table. See the ERSATZ system parameter for additional information on ersztz devices and usage.
|
Device:[P,PN] |
ERSATZ |
System Account Purpose |
|
DSK0:[1,2] |
OPR: |
System operator account. This account has special privileges and is usually password protected. Logging into this account might be considered analogous to logging in as Administrator under Windows or as the superuser under UNIX. Certain commands, for example, will only run, or have greater powers, when executed from this account. |
|
DSK0:[1,4] |
SYS: |
"The" system account. This is the default location for all of the system commands (those with LIT extensions) plus certain configuration files, such as the language files and ersatz.ini. |
|
DSK0:[1,6] |
DVR: |
Terminal driver and language definition file account. Under A-Shell, terminal drivers are embedded in the executable, so the only files you will normally have in this account of the language definition files (e.g. englsh.ldf). |
|
DSK0:[1,7] |
ASHCFG: |
A-Shell configuration files, in particular, printer init (PQI) files. |
|
DSK0:[2,2] |
CMD: |
Command files (i.e. those with CMD or DO extensions). These are the AMOS and A-Shell equivalents of BAT files under DOS or shell scripts under UNIX. |
|
DSK0:[7,0] |
LIB: |
Library files. Function key translation tables, color configuration files, ini.vue (VUE initialization file). |
|
DSK0:[7,1] |
HLP: |
Help files. A-Shell tends to embed help which is associated with system commands in the commands themselves, or use external PDF (Acrobat) or CHM (Windows Compiled Help) files, leaving this directory only for the help files that are displayed from within the VUE command mode with the HELP command. |
|
DSK0:[7,6] |
BAS: |
RUN files placed in this directory can be run from any other location. |
|
DSK0:[7,376] |
|
A-Shell sample program directory |