Orange Micro 4GS APPENDIX D: SPECIFICATIONS OF, RAM EXPANSION CHIPS, APPENDIX E: GLOSSARY, DRAM:, H I T :, D R A M S, B A N K :, B L O C K :, C A C H E :, B U F F E R :

APPENDIX D: SPECIFICATIONS OF

RAM EXPANSION CHIPS

The technical specifications of the RAM chips used to expand the memory of the RamPak are as follows:

2 5 6 K x 4 , o n e m e g a b i t , 1 5 0 n a n o s e c o n d ( o r f a s t e r ) , “ C A S b e f o r e R A S ” r e f r e s h m o d e

D R A M S .

APPENDIX E: GLOSSARY

B A N K : 64K Bytes of memory.

B L O C K : A portion of data 512 bytes in length, as viewed from ProDos.

B U F F E R : A designated area in RAM where a single ProDos block is stored if caching is active.

B U F F E R P O O L : A collection of contiguous buffers used by the cache program to store ProDos blocks.

C A C H E : A storage area in RAM to eliminate disk access time for data.

C E L L I N T E G R I T Y : The ability of a RAM cell to accept and retain data, regardless of the data pattern or cell location. Also see DATA RETENTION.

DATA RETENTION: The ability of a RAM cell to retain data, without errors, when no memory accesses occur over a period of time.

DRAM: Dynamic Random Access Memory.

D Y N A M I C C A C H E A L L O C A T I O N : Allows the program to allocate buffers from the buffer pool as required by the system. Additional buffers are automaticallyallocated

to more frequently used drives.

H I T : An attempt to read a block from disk that has already been cached, thus finding the data in cache memory.

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