012B Board I/O; Ddress Select Jumpers - Intel SYSTEM 310 Configuration Manual

System 310
012B Board Jumpers
Preconfigured 012B boards have all 512K bytes available, so they
have jumpers 77 and 78 connected. Replacing that connection with
one between 78 and 79 disables the bottom two rows of memory chips
(the rows closest to the card edge connector), leaving half of the
memory available.
I/O ADDRESS SELEC JUMPERS
The jumpers in the I/O address select area, shown in Figure 3-1 and
listed in Table 3-6, determine the address of the 8-bit status/error
register. The status/error register logs parity error information that
you can read with an I/O command in software. The 012B boards
have this address preset to 00000H. If you add another 012B board,
or an 056 board that also has this register set at 00000H, you must
relocate one of the boards or the information in the register may not
be valid.
Table 3-6 lists the jumper connections found in preconfigured System
310's. It also lists the significant address lines for the status/error
register that are not determined by jumpers. The first column lists
the address of the status register, from least to most significant bit,
when the corresponding jumper pair in the second column is
connected. The third column lists the names of the signal lines.
Table 3-6. 012B Board I/O ddress Select Jumpers
Status/Error
Register ddress
Connection
Signal Name
0
(low)
42-43
>7'.
D00
0
(low)
44-45
D01
0
(low)
46-47
u?
DO 2
0 (low) 48-49
DO 3
0 (always low)
No jumper D04
0 (always low)
No jumper DO 5
0
(low)
75-76
DO 6 *
0
(always low)
No jumper
D07
0 (low)
51-52
v/
D08
0
( low)
54-55
DO 9
0
( low)
57-58
DO
0 (low)
60-61
Uh
DOB
0
(low)
63-64
oA
DOC
0
(low)
66-67
VJ
DOD
0 (low)
69-70
wg
DOE
0
(low)
72-73
DOF
* D06 can be changed to high by changing the connection shown to
74-75.
3-7