Types of  Expansion bus Architectures used within the PC computer
 

ISA - Industrial Standard Architecture
MCA - Micro channel Architecture (Created by IBM)
EISA - Enhanced Standard Architecture



About the ISA Bus

1.  Has a clock speed limit of  8 MHz
2.  Has a word length of 8 or 16 bits (8 or 16 data lines)
3.  Requires two clock ticks to transfer data (16 bit transfers)
4.  Very slow for high performance disk accesses and high performance video cards



About the EISA Bus

1.  Has a clock speed of  8.33 MHz
2.  Maximum of  a  32-bit wide word length(32 data lines)
3.  Can support lots of devices
4.  Supports older devices which have Slower or Smaller word lengths(ISA)
5.  Transfers data every clock tick.



About MCA

1.  Has a clock speed of  10 MHz
2.  Has a 32 bit word length (32 data lines)
3.  Transfers data every clock tick
 

See Types of  local bus Architectures

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