Why would I have to configure the keyboard layout, if Brazilian (ABNT-2) works perfectly?
All the keys except //? are there (though PgUp, PgDn, Home, End, and \/| need the Fn key), and all keys send the correct codes for an ABNT-2 keyboard.
The keys just have been rearranged a bit to save space. In this case, '/" was pushed up to between Esc and F1, freeing space for the number row.
(To help better visualize the situation: on a full ABNT-2 keyboard, the first row starts with Esc, F1, F2, the second row starts with '/", 1/!/¹, 2/@/², and the third row starts with Tab, Q, W. On the EeePC 701, the first row starts with Esc, '/", F1, F2, the second row starts with 1/!/¹, 2/@/², and the third row starts with Tab, Q, W.)
Of course, now that I know the mnemonic is "the key which would be above Tab if it was a full-sized desktop keyboard", I can simply memorize that it is "Alt-' if on an ABNT-2 keyboard, Alt-` if on a US-International keyboard" (the two kinds of keyboard usually found on Brazil), and hope it works even when ` is a dead key (which it would be on a US-International keyboard layout).