If you can't see anything post output from od -xc /etc/apt/sources.list here (it will be a bit lengthy).

Chris

cat -v /etc/apt/sources.list

^ That should show any non-printable characters.

Or:

sed -n 'l' /etc/apt/sources.list

^ That should display most non-printable characters as the octal values.

For example the new lines will be marked with a $ symbol.

La riga 1 nel file /etc/apt/sources.list non è corretta (type)
Impossibile leggere l'elenco dei sorgenti.

translates to:

Check

• what is the file's first line. Any funny character?

• the permissions of the file /etc/apt/sources.list

As usual return me:

E: La riga 1 nel file /etc/apt/sources.list non è corretta (type)
E: Impossibile leggere l'elenco dei sorgenti.

Please post the output of

sudo LC_ALL=C apt update

^ That will make the command speak English.

Perhaps you have a weird character in the file that's not showing up when you paste it here, try copy&pasting chris2be8's list into a fresh sources.list file.

My sources.list also contains contrib and non-free, and also includes backports and proposed updates, here is the first line:

deb http://deb.devuan.org/merged ascii main contrib non-free

Found 35 updates.

I can't see a mistake in your sources.list. Try again apt update, apt list --upgradable, apt upgrade.

rolfie

## package repositories
deb http://deb.devuan.org/merged/ ascii main contrib non-free 
deb http://deb.devuan.org/merged/ ascii-updates main contrib non-free 
deb http://deb.devuan.org/merged/ ascii-security main contrib non-free 
# deb http://deb.devuan.org/merged/ ascii-backports main 

## source repositories
# deb-src http://deb.devuan.org/merged/ ascii main 
# deb-src http://deb.devuan.org/merged/ ascii-updates main 
# deb-src http://deb.devuan.org/merged/ ascii-security main 
# deb-src http://deb.devuan.org/merged/ ascii-backports main 

Note there is a / after merged which you do not have. Try adding that.

Chris

apt update

after editing your sources.list file and before trying to update?

I mention this as I have overlooked simple things myself, and will again.

# Devuan repositories
deb http://deb.devuan.org/merged ascii          main
deb http://deb.devuan.org/merged ascii-updates  main
deb http://deb.devuan.org/merged ascii-security main
# Devuan sources
deb-src http://deb.devuan.org/merged ascii main
deb-src http://deb.devuan.org/merged ascii-security main
deb-src http://deb.devuan.org/merged ascii-updates main

As usual return me:

E: La riga 1 nel file /etc/apt/sources.list non è corretta (type)
E: Impossibile leggere l'elenco dei sorgenti.

To use https, select a mirror that supports https and use that in your sources.list

Here's a list of package mirrors. Each entry shows which protocols are supported:
http://pkgmaster.devuan.org/mirror_list.txt

For my mistake, have broken "sources.list"......now i have this:

# Devuan repositories
deb https://deb.devuan.org/merged ascii main
deb https://deb.devuan.org/merged ascii-security main
deb https://deb.devuan.org/merged ascii-updates main
#deb https://deb.devuan.org/merged ascii-backports main

# Devuan sources
deb-src https://deb.devuan.org/merged ascii main
deb-src https://deb.devuan.org/merged ascii-security main
deb-src https://deb.devuan.org/merged ascii-updates main
#deb-src https://deb.devuan.org/merged ascii-backports main

When write "sudo apt update" return me :

"E: La riga 1 nel file /etc/apt/sources.list non è corretta (type)
E: Impossibile leggere l'elenco dei sorgenti."

P.S. Sorry for my bad english