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This register controls the direction of I/O bits 1 - 8. A 1 written to a bit will set that
bit to an output, a 0 will set the bit to an input. At reset all bits are set to inputs.
JP2 can be used to add either a 10K Ohm pullup or pulldown to the I/O pins.
GPS BA + 407h Direction
(Write/Read, 8-bit)
This register controls the direction of I/O bits 9 - 16. A 1 written to a bit will set
that bit to an output, a 0 will set the bit to an input. At reset all bits are set to
inputs. JP1 can be used to add either a 10K Ohm pullup or pulldown to the I/O
pins.
GPS6185 RTD ID
GPS BA + 400h - BA + 401h RTD ID (Read only, 8-bit or 16-bit)
RTD ID is a method to identify a board on the ISA bus. There are two 8-bit
registers mapped at 400h and 401h above the board base address. The
registers can be read as two 8-bit or one 16-bit. An internal pointer is auto-
incremented with every read to either address so the data read will step through
the table below. The pointer is set to zero at reset.
GPS BA + 402h RTD ID Reset Pointer (Read only, 8-bit only)
A read to BA + 402 will set a pointer that determines what data will be read when
you read BA + 400h and BA + 401h. The pointer is set to zero at reset.
Index
Data
8-bit read
16-bit read
0 85h
1
Device ID
61h
6185h
2 35h
3
RTD Vendor ID
14h
1435h
4 Revision
LSD
5
EPLD Revision
Revision MSD
Revision
6 - 9
Reserved
Ignore
Ignore
10 G
11 P
GP
12 S
13 6
S6
14 1
15 8
18
16
Board name string
5 5<nul>
