EISA Bus Masters and Master-Specific Slots (98556)

SUMMARY

Most EISA computers support up to a maximum of six EISA bus master slots. If the computer has more than six slots, the others will not support EISA bus master cards. Consult the manufacturer's documentation to find out which slots support EISA bus master cards.

MORE INFORMATION

The original Intel EISA chip set allows only six Master Request (MREQ) and six corresponding Master Acknowledge (MAK) signals, so you can use six EISA slots for EISA bus masters. This limitation is not normally a problem, because it is unusual to have more than six EISA bus masters in a system, but you must make sure that the slot your EISA bus master is in supports EISA bus mastering.

Here is a list of some popular systems and their slots that do NOT support EISA bus masters:

Machine Name          Slots w/o EISA Bus Master Support
-------------------------------------------------------

Compaq SYSTEMPRO      6
AST Premium Tower     7-10
HP Vectra             3 and 5
Gateway 486/33E       7 and 8

The Compaq SYSTEMPRO XL and the Compaq Prosignia use a proprietary Compaq chip set that allows for more than six bus master slots. On these systems, all of the slots support EISA bus master cards.