Lines Matching +full:data +full:- +full:lines
1 .\" -*- nroff -*-
3 .\" Copyright (c) 1996 A.R.Gordon, andrew.gordon@net-tel.co.uk
24 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
51 point-to-point network interface between two similarly configured systems.
52 Data is transferred 4 bits at a time, using the printer status lines for
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
110 data plus one handshake).
114 The signal lines are used as follows:
115 .Bl -tag -width dataxxxx(Pinxx)
117 Data out, bit 0.
119 Data out, bit 1.
121 Data out, bit 2.
125 Data out, bit 3.
127 Data in, bit 0.
129 Data in, bit 1.
131 Data in, bit 2.
133 Data in, bit 3.
138 When idle, all data lines are at zero.
142 sender places the 4 least significant bits on the data lines and lowers
143 the handshake; receiver reads the data and lowers its handshake.
145 The packet format has a two-byte header, comprising the fixed values 0x08,
146 0x00, immediately followed by the IP header and data.
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.
161 The signal lines are used as follows:
162 .Bl -tag -width dataxxxx(Pinxx)
164 Data out, bit 0.
166 Data out, bit 1.
168 Data out, bit 2.
170 Data out, bit 3.
174 Data in, bit 0.
176 Data in, bit 1.
178 Data in, bit 2.
180 Data in, bit 3.
185 When idle, all data lines are at zero.
189 sender places the 4 most significant bits on the data lines and lowers
190 the handshake; receiver reads the data and lowers its handshake.
194 .Bd -literal
214 for handshake-in cannot be used to generate an interrupt.
215 The sender writes the value 0x08 to the data lines, and waits for the receiver
216 to respond by writing 0x01 to its data lines.
221 specially (although the data lines are restored to the zero, idle
228 Busy-waiting loops are used while handshaking bytes, (and worse still when
234 due to the choice of handshake lines; it could theoretically be improved