HP 13255 Technical Information page 13

13255
General Purpose Asynchronous Data
ro~m
Module
13255-910SQ/tl
Rev AUG-Ol-76
Tahle 6.2 Module Bus Pin Assiqnments
-====;:======================:===================================================
, ,
I
t
I
,
I
I
I
I
I
I
Function
I I
Bus
pertorme~:
Input Module status Byte
I
Value
I
Siqnal
-------
...
-----------
-----
...
~ ----~---
...
---
X
ADDR
15
Poll Bit: Not Applicable
X
AOOR
14
X
AODR 13
Module Address: (AODR 11,10,9,4) = (Atl,AtO,A9,A4)
X
AonR
12
Switch Selectabl~ (OOOl)=Data Comm
("101)=Prlnter
Function 50eclfier: ADOPS = 1
ADDR6
=
0
AO =
0
Read Standard status
AO
=
1
Read Alternate 5tatus
nata Bus Bit
Interpr~tation:
Alternate status Is the same as the
standard status unless noted otherwise
~7
Not Used
Bib 0
=
58
On
1
=
SR Off
RS 0
=
C,",
On
1
=
C8 nff
B''l
S.)
s:l
Ai
810
0
= CF On
1
= CF
Off
0 = NO
parity Error
1 =
P~rltv
Error
0
= NO Overrun Error
1
= Overrun Error
o
= Transmit
Hold~nq
Reqister Full
1 = Transmit Holdino
Reaist~r
Empty
o
= Receiver
Req~ster
Empty
1 = Receiver Reqister Full
At 1
AOOR 11
AtO ADnR
10
A9 ADOR 9
X ADDR
8
X
ADOR
1
0
AOOR
6
1
ADOR
5
A4
AOOR
4
X
ADOR
3
X
ADOR
2
X
ADDR
1
AO ADOR
0
---
..
---
-------
... ---~
------- ----
..
-
...
-----
87
BUS
7
86
BUS
6
85
AUS
5
84
AU~ 4
83
BUS
3
B2
AUS
2
B1 PUS
1
BO
8US 0
~----~-~-~----~-~---
-------~--------~---
l=Loqical l=Bus LOw
O=Loqical O=Bus High
X=Don't Care
------~---~----~~----
---~--~-~~-~---------
(Alternate)
o
= Transmission in
Proqress
1 = Transmission Complete
=====:================================================::::=:::=:=::::==:=:=::=::=