Ithaca PcOS Series 80PLUS Programmer's Manual page 60

Control Codes
Printer Status
Function
ASCII
Hexadecimal
Decimal
Function
Response
Function
ASCII
Hexadecimal
Decimal
Function
Response
Function
ASCII
Hexadecimal
Decimal
Function
Response
Page 50
PcOS Series 80PLUS
Inquire receipt paper out
[ENQ] <4>
05H 04H
<5><4>
Is receipt paper out?
ACK <4> (06H 04H)
There is receipt paper.
NAK <4> (15H 04H)
The receipt paper is exhausted.
Inquire cover open status
[ENQ] <8>
05H 08H
<5><8>
Inquire whether the cover is closed.
ACK <8> (06H 08H)
The cover is closed.
NAK <8> (15H 08H)
The cover is open.
Is the buffer empty? Clear IEEE 1284 buffer.
[ENQ] <9>
05H 09H
<5><9>
This command allows the host to know when the print buffer is empty.
If IEEE 1284 is active, this command also clears the response buffer.
ACK <9> (06H 09H)
The buffer is empty.
NAK <9> (15H 09H)
The buffer is not empty.
Rev B 4/13/99
Programmer's Guide