NCR CORPORATION

PC916/PC920

Processor

80386DX

Speed

16/20MHz

Chip Set

Unidentified

Max. Onboard DRAM

None

BIOS

Unidentified

Cache

None

Dimensions

290mm x 106mm

I/O Options

Proprietary external memory bus

NPU Options

80287/80387

CONNECTIONS

Purpose

Location

Purpose

Location

External Battery

J2

Keyboard plug

J5

Power LEDs & keylock

J3

Proprietary external memory bus

S1

Speaker & volume control

J4

EPROM expansion ROMs

U10 & U28

USER CONFIGURABLE SETTINGS

Function

Jumper/Switch

Position

»

Factory configured - do not alter.

J1

N/A

»

Power good signal detect from power supply

JP1

Off

 

Power good signal detect from board

JP1

On

 

DMA speed select 4MHz

JP2

Off

 

DMA speed select 8MHz

JP2

On

»

Monitor type select color

SW1

pins 1 & 2 closed

 

Monitor type select monochrome

SW1

pins 2 & 3 closed

»

NPU 80387 disabled

SW2/1

Off

 

NPU 80387 enabled

SW2/1

On

»

NPU 80287 disabled (Version A)

SW2/2

Off

 

NPU 80287 enabled (Version A)

SW2/2

On

»

Factory configured - do not alter (Version B)

SW2/2

Off

»

DMA page register mode select extended (Version A)

SW2/3

Off

 

DMA page register mode select PC8-standard (Version A)

SW2/3

On

»

Video ROM caching enabled (Version B)

SW2/3

Off

 

Video ROM caching disabled (Version B)

SW2/3

On

»

Fail-safe timer non-maskable interrupt disabled

SW2/4

Off

 

Fail-safe timer non-maskable interrupt enabled

SW2/4

On

»

IRQ 10 disabled

SW2/5

Off

 

IRQ 10 enabled

SW2/5

On

»

IRQ 11 disabled

SW2/6

Off

 

IRQ 11 enabled

SW2/6

On

»

IRQ 12 disabled

SW2/7

Off

 

IRQ 12 enabled

SW2/7

On

»

CPU speed when accessing floppy disk select 16Mhz

SW2/8

On

 

CPU speed when accessing floppy disk select 8Mhz

SW2/8

Off

»

Factory configured - do not alter (Version A)

VC1

N/A

»

Factory configured - do not alter (Version A)

VC2

N/A

 

Notes:If JP2 is not present on main board, JP2 is factory set to open, if JP2 is present then JP2 is

factory set to closed and should not be altered.

Version B, main boards with part numbers of 150-0006935 and later, do not support the 80287.

Location of 80287 NPU is unverified.

On Version A main boards with part numbers of 150-0004426 or later, SW2/switch 3 controls

video ROM caching and DMA is always in extended mode.

If using a third-party video card, video ROM caching should be disabled.

Variable capacitors VC1 and VC2 are present only on Version A main boards.

EXTERNAL MEMORY CARD CONFIGURATION

Size

Bank 0

Bank 1

1MB

(36) 41256

NONE

2MB

(36) 41256

(36) 41256

Note:Location of banks 0 & 1 unidentified. Memory chips are unidentified.

EXTERNAL MEMORY CARD JUMPER CONFIGURATION

Size

J2

1MB

pins 2 & 3, 5 & 6, and 8 & 9 closed

2MB

pins 1 & 2, 4 & 5, and 7 & 8 closed

EXTERNAL MEMORY CARD SWITCH CONFIGURATION

Size

SW1/1

SW1/2

SW1/3

SW1/4

SW1/5

SW1/6

SW1/7

SW1/8

1MB

On

On

On

On

On

On

On

On

2MB

On

On

On

On

On

On

On

On

EXTERNAL MEMORY CARD SWITCH CONFIGURATION (CON’T)

Size

SW2/1

SW2/2

SW2/3

SW2/4

SW2/5

SW2/6

SW2/7

SW2/8

1MB

Off

On

On

On

On

On

On

On

2MB

On

Off

On

On

On

On

On

On