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HMB-16/20

ACER AMERICA CORPORATION

HMB-16/20

Card Type

Memory

Chipset/Controller

N/A

I/O Options

None

Maximum DRAM

8MB (4MB on HPB supplemental memory card)

STARTING ADDRESS

Address

JP1

1.25MB (1MB system RAM)

Pins 1 & 2 closed

4.25MB (4MB system RAM)

Pins 2 & 3 closed

PARITY CHECK

Enabled

JP2

Enabled

Pins 2 & 3 closed

 

Disabled

Pins 1 & 2 closed

MEMORY SIZE

Size

SW1/1

SW1/2

SW1/3

2MB

On

On

On

4MB

Off

On

On

6MB

Off

Off

On

8MB

Off

Off

Off

MEMORY READ/WRITE TIMING

Card Model/System Speed

SW1/4

TP1

HMB-16/100-ns

On

Pins 4 & 9, 3 & 8 closed

HMB-20/85-ns

On

Pins 4 & 9, 1 & 6 closed

 

HMB-16/85-ns

Off

Pins 4 & 9, 3 & 9 closed

 

HMB-20/100-ns

On

Pins 4 & 9, 1 & 6 closed

Note: SW1/4 in the on position enables the zero wait state.

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

Parity Bits

2MB

(16) 514256

None

None

None

(8) 511000

4MB

(16) 514256

(16) 514256

None

None

(8) 511000

6MB

(16) 514256

(16) 514256

(16) 514256

None

(8) 511000

8MB

(16) 514256

(16) 514256

(16) 514256

(16) 514256

(8) 511000

Note:(1) Banks 2 & 3 are located on the HPB daughter card.

(2) The HMB-16 uses 100-ns 514256 RAM chips and 100-ns 511000 parity chips.

(3) The HMB-20 uses 85-ns 514256 RAM chips and 85-ns 511000 parity chips.

MISCELLANEOUS TECHNICAL NOTES

The HMB-16/20 is for use only in Acer interleaved-memory systems.