Connect a [print] object to the output of one of the [==] objects to see what it is doing, or read the help file.

If your number is equal to 1, then it outputs 1, otherwise it outputs 0. You also need to familiarise yourself with execution order - look at the [trigger] helpfile.

However, you might be better off using [select] as follows:

[0 \
|
[sel 1 2 ]
| |
[12 ( [0 (
| |
| /
| /
| /
[0 \

You can also set autoscale to output the range in the direction you want, eg:

[autoscale 1500 0]

You could try using [folder_list] from hcs to compile a list of the files that exist, then read them from that list.

Here's another solution using [tabdump] from zexy

http://www.pdpatchrepo.info/hurleur/reading_array.pd

You could try using the /dev/urandom output via the [shell] object. I had trouble getting it to reliably report a number each time so I forced it with some [spigot] logic. See attached patch.

http://www.pdpatchrepo.info/hurleur/alternative_random_number.pd

A table or array is filled with a number of values, each of which can be addressed by it's 'index'. Look at the help file for [tabwrite]

Put them in all in one directory, then select them randomly with [playlist], or use [folder_list] to load them to [textfile] or [msgfile]. In either case, you can then output the filename to [readsf~].

Use [random] for shuffle play.

[echo 'hola mundo';( is a message, not an object.

[shell] can be found in the ggee library.

Maybe try adding a delay to the loadbang?

[loadbang]
|
[del 1000]
|
[open 1(
|
[comport]

Send a message to pd like:

[; pd midi-dialog 1 0 0 0 0 0 0 0 1 1(

to select the relevant midi device.

You can check the exact message required by receiving pd messages like so:

[r pd]
|
[print]

and then change the midi-settings in the menu.