Both TURMON and TURMONH Turnkey monitor ROMs have a typo/bug in them.
; THIS SUBROUTINE BUILDS 3/6 OCTAL DIGITS IN H&L
;
; SPECIAL RETURN PROVIDED BY A "SPACE", CARRY BIT SET.
; ONLY VALID OCTAL OR "SPACE" ACCEPTED. ALL OTHERS FLAGGED AND
; CONTROL RETURNS TO MONITOR.
...
FDB7 37 STC ; SET THE CARRY
FDB8 C8 RZ ; RETURN IF "SPACE"
FDB9 E6B8 ANI 0B8H ; TEST FOR VALID OCTAL
^^ This should be ANI 0F8H unless you wanted p-w to be interpreted as valid octal. :)
The TURMON PROM Manual has the program listing with the correct value.
.M000
000000 201 123
000001 272 pqr
000002 126 012
000003 254 3?
.M0
000000 123
000001 012
000002 012
?00003 254
.