In teleprinter-era character encoding, how many bits per symbol does the Baudot code (ITA2) use for representing characters?

Introduction:
Historical codes help explain the evolution from telegraphy and teletype systems to modern 8-bit and Unicode encodings. Baudot code (more precisely ITA2) was widely used for teleprinters and early data communications.

Given Data / Assumptions:

• The question refers to the classic Baudot/ITA2 code used in teletype systems.
• We are counting the number of bits per transmitted character symbol.
• No parity or start/stop framing bits are included in the requested count—only the symbol itself.

Concept / Approach:
Baudot (ITA2) represents characters using 5 bits per symbol. Because 5 bits alone cannot encode the full alphabet, digits, and punctuation, Baudot employs shift characters to toggle between “letters” and “figures” modes, effectively multiplexing two symbol tables. This economical bit width matched the bandwidth constraints of early telecommunication channels.

Step-by-Step Solution:
Recall that ITA2 defines 5-bit codes plus special shift/ltr/figs codes.Differentiate symbol bits from line framing (start/stop) added by asynchronous links.Confirm the canonical figure: 5 bits per Baudot/ITA2 symbol.Select the option “5.”

Verification / Alternative check:
Teleprinter documentation (e.g., Teletype Model 33/35) lists 5-bit code points and the letters/figures shifts used to extend the character set.

Why Other Options Are Wrong:

• 1 bit: insufficient to encode a useful set of symbols.
• 8 or 9 bits: correspond to later encodings (ASCII uses 7 bits; extended ASCII/bytes are 8 bits).
• None of the above: invalid because 5 is correct.

Common Pitfalls:
Confusing line framing (start/stop/parity) with symbol width; Baudot codewords are 5 bits, even if the serial frame carries additional bits.

Final Answer:
5