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PB286 And IS/VT286 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
There are two versions of this motherboard. The old motherboard is known as the ISVT286.
New Motherboard (PB286)

Note
1. Upgradeable to 1MB by adding (4)256Kx4 and (2)256Kx1
2. If you want to install Memory Card(s), in your 1 MB RAM system, be sure to select SW1-1 ON, SW1-2 OFF. 

        ษอออออัออออออัอออออออออัอออออออออออออออออป
        บSW1-1ณ SW1-2ณ RAM Sizeณ MEMORY SETTINGS บ
        บ     ณ      ณ         รฤฤฤฤฤฤยฤฤฤฤฤฤฤฤฤฤถ
        บ     ณ      ณ SELECTEDณ BASE ณ EXTENDED บ
        ฬอออออุออออออุอออออออออุออออออุออออออออออน
        บOFF  ณ OFF  ณ 256KB   ณ 256  ณ 0        บ
        บOFF  ณ ON   ณ 512KB   ณ 512  ณ 0        บ
        บON   ณ OFF  ณ 640KB   ณ 640  ณ 0        บ
        บON   ณ ON   ณ 1 MB    ณ 640  ณ 384      บ
        ศอออออฯออออออฯอออออออออฯออออออฯออออออออออ1/4

Old Motherboard (ISVT286)
Note
1. Replace 64K DRAM's with 256K DRAM's to upgrade to 1 MB.

2. 1MB RAM must be split 512 Base/512 Extended.

3. If 640k base is required with extended memory, add a memory card. 

        ษออออออออออออออออออออออัอออออออออออออออออป
        บJ2 (RAM Select Jumper)ณ MEMORY SETTINGS บ
        ฬอออออัออออออออออออออออุออออออัออออออออออน
        บPINS ณMODE (RAM Size) ณ BASE ณ EXTENDED บ
        วฤฤฤฤฤลฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤลฤฤฤฤฤฤลฤฤฤฤฤฤฤฤฤฤถ
        บ1-2  ณ1 MB Mode       ณ 512  ณ 512      บ
        วฤฤฤฤฤลฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤลฤฤฤฤฤฤลฤฤฤฤฤฤฤฤฤฤถ
        บ2-3  ณ640 Mode        ณ 512  ณ 0  OR    บ
        บ     ณ                ณ 640  ณ 0        บ
        ศอออออฯออออออออออออออออฯออออออฯออออออออออ1/4

Math CO-Processor
A math co-processor can be installed in U99, no jumpers need to be changed. Use a: 80287-6 for 6-8-10 MHz systems 80287-8 for 12 MHz systems, 

ฺฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤาฤฤฤาฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฤฟ
ณ                                           J1 ำฤฤฤ1/2  ฺฤฤฤฤฟ              ณ
ณ                                                 ฺฤฤฟภฤฤฤฤู     ฺฤฟ      ณ
ณ ฺฤฟ  ฺฤฟ  ฺฤฟ  ฺฤฟ  ฺฤฟ  ฺฤฟ  ฺฤฟ  ฺฤฟ ฺฤฟฺฤฟ   ณS ณ    ฺฤฟ    ณ ณ      ณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ณ ณณ ณJฑ ณW ณ    ณ ณ    ณ ณ      ณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ณ ณณ ณ2ฑ ณ1 ณ    ณ ณ    ภฤู      ณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ภฤูภฤู   ณ  ณ    ภฤู บฒ       ฺฤฟณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ          ภฤฤฺูฤฟ ฺฤฟ บฒ       ณ ณณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ฺฤฟ  ฺฤฟ ฺฤฟ ณ ณ ณ ณ บฒ ฺฤฟฺฤฟณ ณณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ณ ณ  ณ ณ ณ ณ ณ ณ ณ ณ บฒ ณ ณณ ณภฤูณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ณ ณ  ณ ณ ณ ณ ภฤู ภฤู บฒ ณ ณณ ณฺฤฟณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ภฤู  ภฤู ภฤู         บฒ ภฤูภฤูณ ณณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ                      บฒ       ณ ณณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ฺฤฟ ษอออปฺฤฟ ฺฤฤฤฟ            ภฤูณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ณ ณ บ   บณ ณ ณ   ณ      ฺฤฟฺฤฟฺฤฟณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ณ ณ บ   บณ ณ ณ   ณ ฺฤฤฤฟณ ณณ ณณ ณณ
ณ ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ  ณฒณ ภฤู บ U บภฤู ณ U ณ ณ   ณณ ณณ ณณ ณณ
ณ ภฤู  รฤด  รฤด  รฤด  ภฤู  ภฤู  รฤด  รฤด     บ 9 บ    ณ 8 ณ ณ U ณภฤูภฤูภฤูณ
ณ      ณฒณ  ณฒณ  ณฒณ            ณฒณ  ณฒณ ฺฤฟ บ 9 บฺฤฟ ณ 1 ณ ณ 6 ณฺฤฟฺฤฟฺฤฟณ
ณ      ณฒณ  ณฒณ  ณฒณ            ณฒณ  ณฒณ ณ ณ บ   บณ ณ ณ   ณ ณ 8 ณณ ณณ ณณ ณณ
ณ      ณฒณ  ณฒณ  ณฒณ            ณฒณ  ณฒณ ณ ณ บ   บณ ณ ณ   ณ ณ   ณณ ณณ ณณ ณณ
ณ      ณฒณ  ณฒณ  ณฒณ            ณฒณ  ณฒณ ภฤู ศอออ1/4ภฤู ภฤฤฤู ภฤฤฤูภฤูภฤูภฤูณ
ณ      ณฒณ  ณฒณ  ณฒณ            ณฒณ  ณฒณ          ฺฤฟ ฺฤฟ ฺฤฟ    ฺฤฟฺฤฟฺฤฟณ
ณ      ณฒณ  ณฒณ  ณฒณ ฺฤฟ        ณฒณ  ณฒณ          ณOณ ณOณ ณ ณ    ณ ณณ ณณ ณณ
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Cache Memory
This system does not support cache memory.

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