Dartmouth BASIC escape codes

Every escape that can be typed in GE-235 or GE-635 source, and the code it stores. Escapes are recognised in string literals, REM text and DATA bodies. These two machines share a BASIC and not a character set, so every row below says which one it belongs to. The GE-235's characters are six bits — 64 codes in all, only seven of which print nothing — and are written {0oNN} in octal, because the machine's own listings are octal throughout. The GE-635's are ASCII: 128 codes, with characters given to 32 through 95 and everything else written {0xNN} in hexadecimal. Neither machine has a named escape — no colour, no cursor controls and no graphics — because a Teletype printing on paper has nothing to address. The braces cost nothing to reserve as notation, since neither { nor } is a character on either machine. Filters can be prefilled with ?q= and ?cat= query parameters.

See also the Dartmouth BASIC reference and file formats.

		Description
{0x04}	0x04	End of transmission, which section 2.7 says "turns off the teletype". It is the code a timesharing line hung up on, and it prints nothing on the way past.
{0x07}	0x07	Bell: the gong on the Teletype Model 33, struck to tell a typist a long run had finished. There is no audio path on this machine either, so nothing is heard here and the paper is unmarked.
{0oNN}	any	Any remaining GE-235 code with no character to strike, written as its six-bit value in octal — octal because the machine’s own listings are octal throughout. There is exactly one: 0o12, which reaches the compiler as a code its character table marks unusable in a program. The braces cost nothing to reserve as notation, since neither { nor } is a GE-235 character. Recognised in string literals, REM text and DATA bodies.
{0x0A}	0x0A	Line feed: the paper advances one line and the carriage stays where it is. PRINT sends a carriage return and then this, and the pair together start a new line.
{0x0D}	0x0D	Carriage return: back to column 0 of the same line, without advancing the paper. The return and the paper feed are separate mechanisms on a teletype, so a line that sends only this one overprints what is already there.
{0o32}	0o32	Bell. On a Teletype Model 33 this struck a physical gong, which is how the machine got the typist’s attention at the end of a long run. Nothing is audible here — the GE-235 has no audio path of any kind — but the paper counts it as a control code rather than printing a glyph.
{0xNN}	any	Any GE-635 code with no character to strike, written as its seven-bit value in hexadecimal. Section 2.7 gives characters to 32 through 95 and nothing else, so this covers every code below the space and everything from 96 up — the lower-case half of ASCII among them, which a Model 33 has no keys or type bars for. Recognised in string literals, REM text and DATA bodies.
{0o37}	0o37	Carriage return: back to column 0 of the same line, without advancing the paper. On a teletype the return and the paper feed are separate mechanisms, so a line that sends only this one overprints what is already there.
{0o52}	0o52	Tab. No tab stops are set on this machine and nothing moves for it: PRINT reaches its fifteen-column zones by padding with blanks rather than by tabbing to them, which is why there is no TAB keyword to write it with.
{0o55}	0o55	End of message: the code that closes a paper tape, and the only thing the reader treats as the end of the input. It frames the tape rather than printing on the paper, so nothing is struck for it.
{0o72}	0o72	Line feed: the paper advances one line and the carriage stays where it is. PRINT sends a carriage return and then this, and the pair together start a new line.
{0o77}	0o77	Fill. A punch wrote these into the tape to give the carriage time to finish a return before the next character arrived, and the reader discards them. Nothing is printed for one.
{0x7F}	0x7F	Rub-out, which section 2.7 marks "(tape use only)". A punch overstruck a mistake with every hole in the column, and the reader threw the character away; nothing is printed for one.

Showing 13 of 13 escape codes