lotus



previous page: 2.42  Is there any point in putting more than 16M in an ISA machine?
  
page up: PC Hardware FAQ
  
next page: 2.45  Why is my PC's clock so inaccurate?

2.43 What disadvantages are there to the HiNT EISA chip set?




Description

This item is from the PC Hardware FAQ, by Willie Lim and Ralph Valentino with numerous contributions by others. (v1.25).

2.43 What disadvantages are there to the HiNT EISA chip set?

[From: ralf@alum.wpi.edu (Ralph Valentino)]

The HiNT Caesar Chip Set (CS8001 & CS8002) can come in three different configurations. All three of these configurations have EISA style connectors and are (sometimes incorrectly) sold as EISA motherboards. The differences should be carefully noted, though.

The rarest of these configuration uses a combination of the first HiNT chip (CS8001) and the Intel chip set. This configuration can support the full EISA functionality: 32 address bits, 32 data bits, level sensitive (sharable) interrupts, full EISA DMA, watch dog (sanity) timer, and so forth.

The second configuration is called Super-ISA, which uses both of the HiNT chips. This configuration is very common in low-end models. It supports a very limited functionality: 24 address bits, 32 data bits, edge triggered (non-sharable) interrupts, ISA (16 data, 24 address) DMA, and no watch dog timer. Some EISA boards, such as the Adaptec 1742A EISA Fast SCSI-2 host adapter, can be configured to work in this mode by hacking their EISA configuration file (.CFG) to turn off these features. Other EISA cards require these features and are therefore unusable in these systems.

The final configuration is called Pragmatic EISA, or P-EISA. Like Super-ISA, both HiNT chips are used but external support logic (buffers and such) are added to provide a somewhat increased functionality: 32 address bits, 32 data bits, edge triggered (non-sharable) interrupts, ISA (16 data, 24 address) DMA, and no watch dog timer. The full 32 bits for address and data allow bus mastering devices access to the complete range of main memory. As with Super-ISA, there may be incompatibilities with some EISA cards.

 

Continue to:













TOP
previous page: 2.42  Is there any point in putting more than 16M in an ISA machine?
  
page up: PC Hardware FAQ
  
next page: 2.45  Why is my PC's clock so inaccurate?