HP50g ram and working dir.

[Joe Horn]

(08-18-2017 10:49 PM)Claudio L. Wrote:  

(08-18-2017 08:11 PM)pier4r Wrote:  Even if Claudio told me that directories cannot be saved in port 1 (nor port 2 as far as I know) I remember that the second 50g that I bought for the newRPL had directories in port2.

Just semantics... I said you cannot create a directory structure, not that you can't store directories. As Andreas mentioned, directories are objects and can be stored, but it's a "blob" and cannot be traversed, you can't access individual variables within them.
The filer does some visual stunts for you... it detects that the blob is a directory object, and scans into it "manually", giving the illusion that you can traverse it, but for all other commands it's still a big blob of data.

Yes and no. YES, new variables cannot be created (saved) into directories in ports 1 or 2, and YES, already-existing variables in directories in ports 1 or 2 cannot be purged individually, but NO, it IS possible to RECALL (or evaluate) already-existing variables individually from directories in ports 1 or 2, by specifying them with "port tagged paths". For example, if VAR2 is a variable in a directory called VAR1 which is saved in Port 2, then :2:{VAR2 VAR1} RCL will recall it from that directory. Instead of RCL you can also use EVAL, which is helpful if VAR2 is a program and you want to run it without recalling that entire directory to main memory.

It might also need to be pointed out that directories in ports 1 and 2 are very different from directories in Port 3 in the 50g. Directories in ports 1 and 2 are merely backups of main-memory directories, and are shown as "DIR" objects in the browser. But "DIR" objects in Port 3 are NOT backed up directories from main memory (those are shown as "HPDIR" objects), but are rather DOS directories (AKA folders) which can be accessed by any computer with an SD card reader. *Those* kinds of directories CAN be fully accessed directly by the HP 50g (not only by the filer). You can purge, store, overwrite, recall, and execute any object stored in any Port 3 "DIR" directly, individually, without recalling the entire directory to main memory. The paths are specified as port-tagged DOS paths in string form, e.g. :3:"VAR2/VAR1".

Due to a bug in the HP 50g, port-tagged paths don't work with HPDIR objects in port 3. So if you want to access directories in port 3 the way they can be accessed in ports 1 and 2, you should use DOS directories instead, and use port-tagged string paths as shown in the previous paragraph.

Sorry if the above is already well-known, but I see references to this so seldom that I thought it might be a good time to review it.