Citizen Systems CBM-290 - Manual (Page 27)

CITIZEN 27
6.4 Timing chart
(1) Data Input and Printing Timing
ACK is not outputted.
T1, T2, T3 : 0.5 micro sec. MIN
T4 : 270 ns MAX
T5 : 2.3 micro sec. TYP
T6 : 500 ms MIN (On supplying power)
6.5 Data receiving control
When BUSY signal is "LOW", data from the host can be received. When it being "HIGH",
data can not be received.
6.6 Buffering
4 K bytes input buffer is incorporated. Due to this large buffer, host side is released immediately.