PB286B Upgrade Information

Caution

Only authorized service personnel should upgrade the system. Anyone who wants to upgrade the system themselves should know about the dangers of ESD (Electro-Static Discharge) and the necessary precautions. Unknowingly zapping the components of the computer will void the warranty.

Memory

1.	Find the memory area at the front left side of the motherboard.

2.	Insert the memory chips (64KBit RAM or 256KBit RAM, 120ns) into empty memory sockets of BANK 2. Be careful not to bend the prongs.

3.	BANK 2 has two rows, next to the square chips, of 9 sockets each. These rows may either be empty, have 128K (18 pcs. of 64Kx1 DRAMs), or 512K (18 pcs. of 256x1 DRAMs).

4.	A maximum of 1 Meg may be installed on the motherboard.

5.	Run the SETUP.COM program and change the configuration according to the following table:

Note
The PB286B cannot have a 640k base and 384 extended memory configuration. If 1 MB or more is required, suggest a memory board and leave 640K on the motherboard).

        ╔═════════╤═════════════════╤════════════╤═══════════╤═══════╗
        ║ DRAM    │ Second RAM bank │ Below 1 MB │ Above 1MB │ Total ║
        ╠═════════╪═════════════════╪════════════╪═══════════╪═══════╣
        ║ 0       │     EMPTY       │    512k    │     0     │  512k ║
        ║ 64k     │     128k        │    640k    │     0     │  640k ║
        ║ 256k    │     128k        │    640k    │     0     │  640k ║
        ║ 256k    │     512k        │    512k    │    512k   │ 1024k ║
        ╚═════════╧═════════════════╧════════════╧═══════════╧═══════╝

Math CO-Processor
An 80287-8 co-processor can be installed in socket U33, no jumpers need to be changed.

     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    │     │▓│  │▓│  │▓│  │▓│  │▓│       │▓│        │ │ │ │ │ │ │ │ │ │    │
    │     │▓│  │▓│  │▓│  │▓│  │▓│       │▓│      ▒ └─┘ └─┘ └─┘ └─┘ └─┘    │
    │     └─┘  └─┘  └─┘  └─┘  └─┘       └─┘     JP1┌─┐ ┌─┐ ┌─┐ ┌─┐ ┌─┐    │
    │ ┌─┐ ┌────┐ ┌──────┐  ┌──────┐                │ │ │ │ │ │ │ │ │ │    │
    │ │U│ │    │ │      │  │      │ ╔════╗         │ │ │ │ │ │ │ │ │ │    │
    │ │3│ │    │ │ U35  │  │ U34  │ ║    ║         └─┘ └─┘ └─┘ └─┘ └─┘    │
    │ │7│ │    │ │      │  │      │ ║    ║ ┌─────────┐ ┌────┐┌────┐┌────┐ │
    │ └─┘ │ U  │ │      │  │      │ ║ U  ║ │         │ │    ││    ││    │ │
    │     │ 3  │ └──────┘  └──────┘ ║ 3  ║ │         │ │ U  ││ U  ││ U  │ │
    │ ┌─┐ │ 6  │                    ║ 3  ║ │   U32   │ │ 3  ││ 3  ││ 2  │ │
    │ │ │ │    │ ┌──────┐  ┌──────┐ ║    ║ │         │ │ 1  ││ 0  ││ 9  │ │
    │ │ │ │    │ │      │  │      │ ║    ║ │         │ │    ││    ││    │ │
    │ │ │ │    │ │ U39  │  │ U38  │ ║    ║ │         │ │    ││    ││    │ │
    │ │ │ └────┘ │      │  │      │ ╚════╝ └─────────┘ │    ││    │└────┘ │
    │ └─┘        │      │  │      │                ┌─┐ └────┘└────┘       │
    │            └──────┘  └──────┘                │ │ ┌────┐┌────┐┌────┐ │
    │ ┌─┐                                          │ │ │    ││    ││    │ │
    │ │ │ ╔═╗╔═╗╔═╗╔═╗╔═╗╔═╗╔═╗╔═╗╔═╗  ┌─┐ ┌─┐     └─┘ │ U  ││ U  ││ U  │ │
     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Cache Memory
This system does not support cache memory.

Video Memory
This system has a video card, upgrade depends on card.