The characters for backspace and enter are actually "hard coded" in the EXPECT routine.
Code:
L1729 .BYTE $86,'EXPEC',$D4
.WORD L1701 ; link to ."
EXPEC .WORD DOCOL
.WORD OVER
.WORD PLUS
.WORD OVER
.WORD PDO
L1736 .WORD KEY
.WORD DUP
.WORD CLIT
.BYTE $E
.WORD PORIG
.WORD AT
.WORD EQUAL
.WORD ZBRAN
L1744 .WORD $1F ; L1760-L1744
.WORD DROP
.WORD CLIT
.BYTE 08 ;; <<-- Backspace character
.WORD OVER
.WORD I
.WORD EQUAL
.WORD DUP
.WORD RFROM
.WORD TWO
.WORD SUB
.WORD PLUS
.WORD TOR
.WORD SUB
.WORD BRAN
L1759 .WORD $27 ; L1779-L1759
L1760 .WORD DUP
.WORD CLIT
.BYTE $0A ;; <<--- Newline character to end a line.
.WORD EQUAL
.WORD ZBRAN
L1765 .WORD $0E ; L1772-L1765
.WORD LEAVE
.WORD DROP
.WORD BL
.WORD ZERO
.WORD BRAN
L1771 .WORD 04 ; L1773-L1771
L1772 .WORD DUP
L1773 .WORD I
.WORD CSTOR
.WORD ZERO
.WORD I
.WORD ONEP
.WORD STORE
L1779 .WORD EMIT
.WORD PLOOP
L1781 .WORD $FFA9
.WORD DROP ; L1736-L1781
.WORD SEMIS