Memory Expansion Board   (250-4030)      Settings       Faxback Doc. # 2027

Note: Refer to Faxback Doc. # 2029 for Board Layout.

Use two 250-3062 Ram Kits per .5meg; the chip kit contains nine 256K X 1 
DRAMS at 150 nanoseconds.

This Board comes configured with 1 Meg of memory:

Bank    S1-5    S1-6                   (+) normal configuration
0        On      On  (512k)            (ON is towards the switch number) 
1        Off     On  (1 Meg) (+)
2        On      Off (1.5 Meg)
3        Off     Off (2 Meg)

Board   S1-1    S1-2    S1-3    S1-4

1st      Off     On      On      On  (+)
2nd      Off     Off     On      On
3rd      Off     On      Off     On
4th      Off     Off     Off     On
5th      Off     On      On      Off
6th      Off     Off     On      Off
7th      Off     On      Off     Off

         Start     Start     Start     Start
        Address   Address   Address   Address
Board    Bank0     Bank1     Bank2     Bank3

1st     100000    180000    200000    280000  (+)
2nd     300000    380000    400000    480000
3rd     500000    580000    600000    680000
4th     700000    780000    800000    880000
5th     900000    980000    A00000    A80000
6th     B00000    B80000    C00000    C80000
7th     D00000    D80000    E00000    E80000

S1-7 and S1-8 Off    (+)

*Note: Dip switch number 8 is used to disable the first board installed
(Address 1.0MB thru 1.5MB) for other options which use this address space.
To select this option configure dip switch 8 to the "On" position, on the
first memory board installed only.

Set dip switches 5, 6 and 8 On (0) or Off (1) as follows:

5   6   8

ON  ON  OFF   If only bank 0 contains memory chips.
OFF ON  OFF   If banks 0 and 1 contain memory chips.
ON  OFF OFF   If banks 0,1, and 2 contain memory chips.
OFF OFF OFF   If banks 0,1,2, and 3 contain memory chips.

*NOTE: Dip switch 7 is not used. Dip switch 8 is used to disable the first
512K memory on the first board installed (address 1.0 MB through 1.5 MB) 
for other options which use this address space. To select this option 
configure dip switch 8 to the ON position on the first memory board 
installed only.

5. Set the start address of memory bank 0 by setting dip switches 1-4 ON (0)
   or Off (1). The dip switches are to be set on 1 megabyte boundaries
   depending upon whether the Memory Expansion Board is the 1st, 2nd, 3rd...
   or last (7th), Memory Expansion Board in the computer.

              DIP           START     START     START      START
            SWITCHES       ADDRESS   ADDRESS   ADDRESS    ADDRESS
          1   2   3   4    BANK 0    BANK 1    BANK 2     BANK 3

1st Brd.  Off On  On  On   100000    180000    200000     280000
2nd Brd.  Off Off On  On   300000    380000    400000     480000
3rd Brd.  Off On  Off On   500000    580000    600000     680000
4th Brd.  Off Off Off On   700000    780000    800000     880000
5th Brd.  Off On  On  Off  900000    980000    A00000     A80000
6th Brd.  Off Off On  Off  B00000    B80000    C00000     C80000
7th Brd.  Off On  Off Off  D00000    D80000    E00000     E80000

(RJS/jej-12/10/94)