It is absent in principle on the stock firmware, but there is Telnet, which does not allow transferring files to the server directly, which leads to problems with automatic firmware ... Telnet login and password:
Login:nexxadmin
Password:y1n2inc.com0755
However, the latest version of Prometheus supports firmware on the drain.

How to flash Asus portgoldenhandles

1. Throw on the flash firmvare.trx
2. We stick the flash drive into the router
3. We go to the router by telnet, you can through putty , address 192.168.8.1
Login: nexxadmin
Password: y1n2inc.com0755
4. We enter

5. Just in case, we make a backup

6. We sew


User instruction providedFreize , for which he thanks a lot!

0 and 19
Available gpio on Nexx WT3020

2 and 18

bit²(bit) - amount of information ¹ (usually used to denote the connection speed and the amount of information transmitted);
byte^2,3 - amount of information ¹ equal to8bit (usually used to denote the amount of data on the media).

1) The term “amount of information” is used in devices for digital processing and transmission of information, for example in digital computing (computers), to record the amount of storage devices, the amount of memory used by a computer program.
2) In accordance with the international standard IEC 60027-2, the “bit” and “byte” units are used with SI prefixes.
3) Historically, there is such a situation that the name “byte” is incorrect (instead of 1000 = 10³accepted 1024 = 2¹⁰) used (and use) SI prefixes: 1 Kbyte = 1024 bytes, 1 MB = 1024 Kbytes, 1 Gbytes = 1024 Mbytes, etc. At the same time, the designation Kbytes start with a capital letter unlike the lowercase letter “k” to designate a multiplier ten³.

A = 4 MB flash - no USB

AD, H, F are absolutely identical devices, the only difference is in the firmware that comes from the factory with the Chinese and English interface
The base of modems for support is increased in the H version compared to F
AD didn’t feel, but I suspect that they added some dLNA / UPNP thread, and I didn’t see it on sale, and I don’t see any reason to overpay for something that can be implemented with alternative firmware (I still make backups with the stock programmer and sew everything my heart desires)

What does the F model show that at some point in time (during the merging of Lede with OpenWRT, in version 17.01.2-17.01.3) the firmware stopped loading, I suspect that they changed something in the hardware, and specifically something was namut in the core with support for the SPI interface on which the entire firmware sits
But in recent versions of OpenWRT this problem is not noticed.

I checked it very simply, two devices purchased with a difference of 1 year on native Flash-ah, the same firmware was launched on one, and not on the other.
after updating OpenWRT to version 17.01.4, the firmware compiled with the same configuration worked on both devices