Lines Matching +full:four +full:- +full:byte

1 .\" -*- nroff -*-
3 .\" Copyright (c) 1996 A.R.Gordon, andrew.gordon@net-tel.co.uk
51 point-to-point network interface between two similarly configured systems.
54 and any standard AT-compatible printer port with working interrupts may be used.
73 .Bl -tag -width Fl
91 .Bd -literal
93 	2	15	Data0 -> ERROR*
94 	3	13	Data1 -> SLCT
95 	4	12	Data2 -> PE
96 	5	10	Data3 -> ACK*
97 	6	11	Data4 -> BUSY
98 	15	2	ERROR* -> Data0
99 	13	3	SLCT   -> Data1
100 	12	4	PE     -> Data2
101 	10	5	ACK*   -> Data3
102 	11	6	BUSY   -> Data4
103 	18-25	18-25	Ground
109 The connections are symmetric, and provide 5 lines in each direction (four
115 .Bl -tag -width dataxxxx(Pinxx)
139 Each byte is signalled in four steps:
145 The packet format has a two-byte header, comprising the fixed values 0x08,
148 The start of a packet is indicated by simply signalling the first byte
151 the data lines (i.e., writing the ones-complement of the previous nibble
154 Note that the end-of-packet marker assumes that the handshake signal and
155 the data-out bits can be written in a single instruction - otherwise
156 certain byte values in the packet data would falsely be interpreted
157 as end-of-packet.
162 .Bl -tag -width dataxxxx(Pinxx)
186 Each byte is signalled in four steps:
194 .Bd -literal
195 Length (least significant byte)
196 Length (most significant byte)
198 Fixed byte 0x08
199 Fixed byte 0x00
201 Checksum byte.
205 nor the checksum byte.
214 for handshake-in cannot be used to generate an interrupt.
218 signalling the first byte of the packet (the length byte).
228 Busy-waiting loops are used while handshaking bytes, (and worse still when