That was standard behaviour for most Microsoft-derived BASIC implementations, since it ensured the end of program text was always marked. On the C64, I entered

That was standard behaviour for most Microsoft-derived BASIC implementations, since it ensured the end of program text was always marked. On the C64, I entered 6502 opcodes directly using the FastLoad monitor, which lacked an assembler like most other monitor programs including the +4's. To this day I can still do things like a9 00 8d 20 d0 60 from memory (lda #0 sta $d020 rts). When we got a KIM-1 from our high school math teacher, we already knew how to program it.