[GTALUG] Following on Stewart's talk... Epson receipt printer

[William Park]

During Stewart's talk last night, someone mentioned that Epson receipt
printer had too small buffer and had to time print jobs to avoid losing
data.

There are 2 ways to get printer BUSY status:

1.  You can query the printer for "online/offline" status by sending
	DLE EOT 1
    (0x10 0x04 0x01) and it will return 1 byte.  If bit 3 (0x08) is
	- 1 -- it is "offline"
	- 0 -- it is "online"

2.  You can turn on ASB (automatic status back), where printer will send
    4 bytes status back to you whenever status changes, such as pressing
    FEED button, buffer full, paper out, etc.
    
    To turn on "online/offline" status reporting, send
	GS a 2
    (0x1d 0x61 0x02).  To turn off "online/offline" status reporting,
    send
	GS a 0
    (0x1d 0x61 0x00).  From the 4 bytes returned, if bit 3 (0x08) of
    first byte is
	- 1 -- it is "offline"
	- 0 -- it is "online"
-- 
William