|
| |
| | PC bus systems |
 | | One of the most important points to note regarding the MCA bus was that it was not backwards compatible with the ISA bus (as the ISA bus had been with the XT bus). | | | An enhanced version of the XT bus was designed for use in the IBM-AT ('Advanced Technology') which was introduced in 1984. | | | The bus mastering was not a complete or perfect implementation due to certain limitations such as a request by a Bus master for 'Bus hand-off' requiring several cycles for completion and the master having to relinquish the bus periodically to allow memory refresh (or do the refresh itself). |
|
http://www.csn.ul.ie/~stephen/buses.html
|
|
| |
| | IBM PC |
| | The processor was still a 4.77 MHz Intel 8088 and the expansion bus still 8-bit ISA with XT bus architecture. | | | The "IBM Personal Computer XT" was an enhanced machine designed for business use. | | | The lower-cost and more general PCI bus was introduced in 1994 and has now become ubiquitous. |
|
http://www.worldhistory.com/wiki/I/IBM-PC.htm
|
|
| |
| | Extended Industry Standard Architecture : EISA |
| | The Extended Industry Standard Architecture (in practice almost always shortened to EISA) is a bus standard for IBM compatibles that extends the ISA bus architecture to 32 bits and allows more than one CPU to share the bus. | | | Unlike MCA, EISA can accept older XT bus architecture and ISA boards. | | | The bus mastering support is also enhanced to provide access to 4 GB of memory. |
|
http://www.fastload.org/ei/EISA.html
|
|
|
