Need help with Jumpering Imsai SIO board

From: Don Caprio <caprio_at_dcms.com>
Date: Sun Apr 7 01:24:57 2002

I have an Imsai SIO Rev 3 serial card. I have the docs but the last section
of the manual may be missing. I've read the section on how to set the
two jumpers for the baord address but I'm having trouble translating.
Could someone who knows this subject please help me to figure out the
address of this SIO card?


Jumps on the baord are set like this:

               C7 (port Select 1)

           1 16
           2 ---- 15
           3 14
           4 ---- 13
           5 12
           6 ---- 11
           7 ---- 10
           8 9

               D6 (port Select 0)

           1 16
           2 15
           3 16
           4 13
           5 ---- 12
           6 11
           7 10
           8 ---- 9

Here is the s-ction out of the manual:

                          C7

     A7 --+---------- 1 16 ------+---------|
          |___|>o--- 2 15 ______| |
     A6 --+---------- 3 14 ------+---------|
          |___|>o--- 4 13 ______| |
     A5 --+---------- 5 12 ------+---------|
          |___|>o--- 6 11 ______| |
     A4 --+---------- 7 10 ------+---------|
          |___|>o--- 8 9 ______| |---)
                                                | )o-------
                 --- 1 16 ------+---------|---)
                 --- 2 15 ______| |
                 --- 3 14 ------+---------|
                 --- 4 13 ______| |
           I/O --- 5 12 ------+---------|
           MM --- 6 11 ______| |
           MM --- 7 10 ------+---------|
           I/O --- 8 9 ______| |

                         D6

OK, so I know that A7=0, A6=0, A5=0 and A4=1, It's not Memmory mapped IO so
jumpers go on pins 5 and 6. So where are A3-A0, on D6?. I think the address is:
   
  A7 0
  A6 0
  A5 0
  A4 1
  A3? 0
  A2? 0
  A1? 1
  A0? 1

  and the answer is 013H ????

 
"The board address is selected by jumpers or a DIP switch in locattion C7 and
 D6. There are two cases for which this board may be jumpered: 1) to respond
 to Input/output instructions and 2) to respond to memory access instructions.
 The case of input/output instructions will be treated first.

 In selection location D6 pins 8 and 9 must be jumpered together and pins 5 and
 12 must be jumbered together. The user must jumper socket C7 so when the
 desired I/O Port address appeas on the address lines, the inputs to the NAND
 gate from bits A4 through a7 are high. If, for instance, address bit 6 is
 desired to be a 0 when the board responds, then pins 4 and and 13 would be
 jumpered together. If address bit A6 was desired to be 1, then either pins
 3 and 14 may be jumpered together or 3 and 13 may be jumpered together,
 since 13 and 14 are tied to the common address selection input.

 It is suggested, however, that when jumpers are being used,
 pins 3 and 13 be connected together to provide a easy visual indication of
 whether the address bit is a 1 or 0 since that will correspond to whether
 jumpers are slanted or straight across the jumper socket."
...

Thanks for the help.
Received on Sun Apr 07 2002 - 01:24:57 BST