Also, while some central Asians could read and write (they had courrier relay to deliver letters), their administrative/taxing/military system, the decimal system, worked without any writing for two thousand years, only by making a mark on a wooden branch for each person in an Arban, a mark on another for each Arban, again for each Ja'un, again for each minggan. That's how they counted and this was taught without text for at least 1500 years (Mongols wrote something about it in the 13th century, but this system is at least from 300BCE and the Xiongnus)
I'd strongly suggest not getting bogged down in the details of what various forms of notional recording are --- ink on paper, etching on stone, holes punched in paper, magnetic field alignments in rust (spinning, sequential, or otherwise), bitfields in memory arrays, holographic images ...
Records are created by varying matter in space to transmit messages over time.
Signals are created by varying energy in time to transmit messages over space.
Signals transmit encoded symbolic messages from a transmitter across_ space_ through a channel by variations in energy over time to a receiver potentially creating a new record.
Records transmit encoded symbolic messages from a writer through a substrate across time by variations in matter over space to a reader potentially creating a new signal.
The symmetric equivalence between records and signals is one that I seem to have come up with myself (I'm unaware of it being noted elsewhere, though bits of it have been observed, e.g., speech is conversation in space, writing is conversation in time). How significant it is I really don't know, though something tells me it should be important.