Looks pretty nice and interesting. Also off-topic: Is GrammerOS an actual OS or is it a shell like MirageOS or DCS?

Command prompt O.o
Nicely done!

I won't be releasing an update since I got caught up with other issues (and I didn't have computer access most of the day). I modified the AFA() command (Add File Association) so that it would check if the file association has been made (basically, it won't make the same association twice, that is redundant and takes up memory). I also added RFA() (Remove File Association) and I have started work on the OPEN() function, which opens files based on file associations. I am currently coding in all of the default stuff, so ION programs will open with either DoorsCS7, MirageOS, ION, or Noshell, for example. You can also do something like AFA( Game,'BATB') and then when you do OPEN( Game), FileSyst will install the BatLib hook before running the game. The filetypes I plan to add as defaults:

ION
MOS (MirageOS)
DCS7 (anything DoorsCS7 can run)
DCS6
C3 (Celtic3)
OMNI (Omicalc)
XLIB (xLIB)
BATB (BatLib Basic)
BAT (BatLib assembly)
GRAM (Grammer programs)

I will probably add more later, but those are my main concerns I am testing DCS7 first.

Yeah, I am trying to make it a fixed width-font, but since I am using BASIC, it is slow. I will probably add back in the text display commands in FileSyst to make it much faster and smoother.

The program in the screenshot uses FileSyst (which is an app) to access the folders and files, otherwise, the program is coded in BASIC.

Hehe, thanks I want FileSyst to be completely accessible to BASIC programs and programmers.

As a side note, about 9 hours ago, before I went to bed, I had made progress on the OPEN() command. I need to fix a few minor issues, but basically, if you have DoorsCS7 on your calculator and it can open a file type, OPEN() will work. I still need to program in all of the other apps and programs, though, such as for BatLib, Grammer, Omnicalc, and Axe Fusion programs.

To think of File Associatons, it is basically like adding a ".txt" or ".exe" or ".py" to the end of a file name. FileSyst does not actually check the header or contents of the program to see what it needs to be run with. Instead, if you want to assign a program the BatLib file type, for example:
dim(0
CD(Zeda:Games)
VPTR(prgmRPG, RPG)   ;creates a file that links to the program "RPG"
AFA( RPG,'BATB')        ;Add the file association  for BatLib BASIC
Return            ;Exist the FileSyst parser and return to BASIC
Then, whenever you do OPEN( RPG), FileSyst will try to install BatLib, then run the program.

I know, but FileSyst doesn't use DoorsCS7 except for when the user wants to run a DoorsCS7 program (or some program that DoorsCS7 can run). For example, if the user doesn't have MirageOS on their calculator, but they have DoorsCS7, and they are trying to run a MirageOS program, FileSyst will open up DoorsCS7 and use its RunProg call.

Using the File Association feature, you can open files with certain apps or programs. I even plan to make it so that even BASIC programs can be used to open files o.o (For example, if you try to open up game data, you can make it auto-launch the actual BASIC game, simply by telling FileSyst that the BASIC program is what opens that file type)
EDIT:
To expand a little more, FileSyst stores files with the following format:

1 byte 1 byte n bytes 1 byte 33 bytes 1 byte 2 bytes n 2 bytes n

Type (1Fh indicates it is a folder, all other types are open) Name Size Name Icon (If this is -1, it is a custom icon, 0 is default, anything else is a preset) IconData (If the Icon is not a custom Icon, this is omitted Info (this is for info about Hidden,Locked, Shortcut, or OS var, among other things) Fields Size Fields Data Data Size File Data

Fields have a header byte so there are up to 256 different fields. Field 0 contains information about file associations, Field 1 contains a file description. If the field doesn't have any data, it is removed. If there is no field data, then Field Data is removed and Field Size is set to zero.

Field 0 is where FileSyst figures out which program  or app to open to handle the file.

Also, as an update, here is a screenie where I run the BASIC program MORPION40  (Tic-Tac-Toe) from DCS7 and DK5ION (DonkeyKong) as an ION program from DCS7.

Looking nice, but can you also use it in basic programs?

Sorunome, that screenshot is of it being used in a BASIC program.

And if yes, is it compatible with BatLib as it uses dim( too?

The answer is yes and no. The two cannot work at the same time, but in this update I will introduce a new command OPEN() that is able to open BatLib programs (among other things). Also, a bunch of BatLib commands are provided at the moment with FileSyst, though some may be removed later.

So as to the update, I have OPEN() working for a handful of file types! These include BASIC, Assembly, xLIB, Omnicalc, BatLib, Celtic 3, Grammer, DoorsCS7 BASIC, DoorsCS7 Assembly, MirageOS, ION, DoorsCS6 Assembly. I will probably be making more adjustments, but it is pretty well functioning at the moment. On top of that it allows you to run programs that are archived and I spent a good portion of today making it so that it would return to the calling program properly. I updated prgmCMD to include the OPEN command and you can see as it opens DK5ION that this should be very useful!
EDIT: Also, I started work on a tutorial.