US Logic Omni III
                           System Memory              Faxback Doc. # 17550

You can increase memory on the main logic board to a total of 256 MB.  The
computer requires SIMMs rated at 70ns or faster.  This system will work 
with non-parity SIMMS.

┌──────────────────────────────┐
│System Memory Configurations: │
└──────────────────────────────┘

The following table shows the number and type of SIMMs required for each
memory configuration.

Note: 36 bit SIMM's storage capacity are four (4) times the capacity of
      a 9 bit SIMM. 

      Example: a single 1 MB X 36 SIMM will provide  4 MB of memory
               a single 2 MB X 36 SIMM will provide  8 MB of memory

                  SIMM TYPE TO FILL EACH BANK
┌───────────┬──────────────┬──────────────┬────────────┬──────┐
│SIMM1      │ SIMM2        │ SIMM3        │ SIMM4      │Total │
├───────────┼──────────────┼──────────────┼────────────┼──────┤
│256KBx36   │ ---------    │ ----------   │ ---------- │  1MB │
│256KBx36   ┤256KBx36      │ ----------   │ ---------- ┤  2MB │
│256KBx36   ┤ ---------    │ 256KBx36     │ ---------- ┤  2MB │
│256KBx36   │256KBx36      │ 256KBx36     │ ---------- │  3MB │
│256KBx36   │256KBx36      │ 256KBx36     │ 256KBx36   │  4MB │
├───────────┼──────────────┼──────────────┼────────────┼──────┤
│512KBx36*  │ ---------    │ --------     │ ---------  │  2MB │
│512KBx36*  │512KBx36*     │ ---------    │ ---------  │  4MB │
│512KBx36*  ┤----------    │ 512KBx36*    │ ---------- ┤  4MB │
│512KBx36*  │512KBx36*     │ 512KBx36*    │ ---------  │  6MB │
│512KBx36*  │512KBx36*     │ 512KBx36*    │ 512KBx36*  │  8MB │
├───────────┼──────────────┼──────────────┼────────────┼──────┤
│1MBx36     │----------    │ -----------  │ ---------  │  4MB │
│1MBx36     │1MBx36        │ -----------  │ ---------  │  8MB │
│1MBx36     ┤ ---------    │ 1MBx36----   ┼ ---------- ┤  8MB │
│1MBx36     │1MBx36        │ 1MBx36       │ ---------  │ 12MB │
│1MBx36     │1MBx36        │ 1MBx36       │ 1MBx36     │ 16MB │
├───────────┼──────────────┼──────────────┼────────────┼──────┤
│2MBx36*    │----------    │ ----------   │ --------   │  8MB │
│2MBx36*    │2MBx36*       │ ----------   │ --------─  │ 16MB │
│2MBx36*    │ ---------    │ 2MBx36*      │ ---------- │ 16MB │
│2MBx36*    │2MBx36*       │ 2MBx36*      │            │ 24MB │
│2MBx36*    │2MBx36*       │ 2MBx36*      │ 2MBx36*    │ 32MB │
├───────────┼──────────────┼──────────────┼────────────┼──────┤
│4MBx36     │----------    │ -----------  │ ---------  │ 16MB │
│4MBx36     │4MBx36        │------------  │ -------- ─ │ 32MB │
│4MBx36     │------        │ 4MBx36       │ ---------  │ 32MB │
│4MBx36     │4MBx36        │ 4MBx36       │            │ 48MB │
│4MBx36     │4MBx36        │ 4MBx36       │ 4MBx36     │ 64MB │
├───────────┼──────────────┼──────────────┼────────────┼──────┤
│8MBx36*    │-----------   │ --------     │ --------   │ 32MB │
│8MBx36*    │8MBx36*       │ --------     │ --------   │ 64MB │
│8MBx36*    │------------  │ 8MBx36*      │ --------   │ 64MB │
│8MBx36*    │8MBx36*       │ 8MBx36*      │ -----      │ 96MB │
│8MBx36*    │8MBx36*       │ 8MBx36*      │ 8MBx36*    │128MB │
├───────────┼──────────────┼──────────────┼────────────┼──────┤
│16MBx36    │ -----------  │ -----------  │ ---------  │ 64MB │
│16MBx36    │16MBx36       │ -----------  │ --------   │128MB │
│16MBx36    │ -----------  │ 16MBx36      │ --------   │128MB │
│16MBx36    │16MBx36       │ 16MBx36      │ --------   │192MB ┤
│16MBx36    │16MBx36       │ 16MBx36      │16MBx36     ├256MB │
├───────────┼──────────────┼──────────────┼────────────┼──────┤
│32MBx36*   │-----------   │ -----------  │ ---------  │128MB │
│32MBx36*   │32MBx36*      │ -----------  │ --------   │256MB │
│32MBx36*   │-----------   │ 32MBx36*     │ --------   │256MB │
└───────────┴──────────────┴──────────────┴────────────┴──────┘
* means dual-bank DRAM

┌─────────────────────────┐
│Main Logic Board Layout: │
└─────────────────────────┘
     ┌────────────────────────────────────────────────────────────────────┐
     │        ........DRAM............          ........SRAM..........    │
     │        . ┌───────────────────┐.        B .┌┬───────┐ ┌┬──────┐  B  │
     │        . ├────────────────SI1┤.        A .└┴─U19───┘ └┘U29─q─┘. A  │
     │        . ├────────────────SI2┤.        N .┌┬───────┐ ┌────── ┐. N  │
     │        . ├────────────────SI3┤.        K .└┴─U20───┘ └─U30── ┘  K  │
     │        . └────────────────SI4┘.        1 .┌┬───────┐ ┌────── ┐  0  │
  B  │        ........................        .  └┴─U21───┘ └─U31── ┘  .  │
  a  │                                        .  ┌┬───────┐ ┌────── ┐  .  │
  c  │                                        .  └┴─U22───┘ └─U32── ┘  .  │
  k  │                                        ..........................  │
     │                                                                    │
  o  │                                                                    │
  f  │      ┌──────────────┐                                              │
     │      └──────────────┘                                              │
  C  │                                     ┌────────────────┐             │
  o  │      ┌──────────────┐               │                │             │
  m  │      └──────────────┘               │                │             │
  p  │                                     │                │             │
  u  │      ┌──────────────┐               │                │             │
  t  │      └──────────────┘               │                │             │
  e  │                                     │                │             │
  r  │┌────────────┬────────┐              │                │             │
     │└────────────┴────────┘              └────────────────┘             │
     │                                     Tag RAM                        │
     │┌────────────┌────────┐             ┌┬──────────┐                   │
     │└────────────┴────────┘             └┴───U27────┘                   │
     │                                                                    │
     │┌────────────┬────────┐ ┌────────┐                                  │
     │└────────────┴────────┘ └────────┘                                  │
     │                                                                    │
     │┌────────────┬────────┐ ┌────────┐                                  │
     │└────────────┴────────┘ └────────┘                                  │
     └────────────────────────────────────────────────────────────────────┘

┌──────────────────┐
│Installing SIMMs: │
└──────────────────┘

Note the following before installing SIMMs:

° Install only one type of SIMM within a single bank.
° Retain the antistatic packaging the SIMMs are shipped in, in case you
  later remove SIMMs.

Before you begin, carefully read the following steps and the documentation
provided with the memory kit. To install SIMMs:

1. Turn off the computer, and disconnect all cables.
2. Discharge any accumulated static electricity from your body by touching
   a grounded metal object. Then, open the computer.
3. Install each SIMM in the appropriate socket.
   To install a SIMM in Bank A, align the notch in the center of the SIMM
   with the raised area in the center of the socket. Holding the SIMM by
   the edges, tilt it to a 45-degree angle from the main logic board. 
   Press the metal-edged connector into the socket, and firmly seat the
   SIMM. Then, press the top edge of the SIMM toward the retaining clips
   until the SIMM latches into place.

   To install SIMMs, begin with the socket nearest the back of the
   computer.  
4. Be sure the internal cables are securely connected and do not cause
   mechanical interference. Then, close the computer.
5. Reconnect all cables.
6. Run the setup* utility to store the new memory value.

* The setup utility is started by pressing DEL during the cpu startup.

┌────────────────┐
│Removing SIMMs: │
└────────────────┘

Before removing or rearranging SIMMs, be sure the new configuration is a
valid configuration. Begin with socket nearest the front of the computer.

To remove a SIMM, open the retaining clips and push the top edge of the
SIMM away from the clips until the SIMM is at a 45-degree angle from the 
main logic board. Then, pull the SIMM away from the board. Store the SIMM in 
an antistatic package.

Run the setup* utility to store the new memory value. 

* The setup utility is started by pressing DEL during the cpu startup.

(cc/tmc-12/04/95)