| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081 |
- Some notes for ftape users with PCI motherboards:
- =================================================
- The problem:
- ------------
- There have been some problem reports from people using PCI-bus based
- systems getting overrun errors.
- I wasn't able to reproduce these until I ran ftape on a Intel Plato
- (Premiere PCI II) motherboard with bios version 1.00.08AX1.
- It turned out that if GAT (Guaranteed Access Timing) is enabled (?)
- ftape gets a lot of overrun errors.
- The problem disappears when disabling GAT in the bios.
- Note that Intel removed this setting (permanently disabled) from the
- 1.00.10AX1 bios !
- It looks like that if GAT is enabled there are often large periods
- (greater than 120 us !??) on the ISA bus that the DMA controller cannot
- service the floppy disk controller.
- I cannot imagine this being acceptable in a decent PCI implementation.
- Maybe this is a `feature' of the chipset. I can only speculate why
- Intel choose to remove the option from the latest Bios...
- The lesson of this all is that there may be other motherboard
- implementations having the same of similar problems.
- If you experience a lot of overrun errors during a backup to tape,
- see if there is some setting in the Bios that may influence the
- bus timing.
- I judge this a hardware problem and not a limitation of ftape ;-)
- My DOS backup software seems to be suffering from the same problems
- and even refuses to run at 1 Mbps !
- Ftape will reduce the data-rate from 1 Mbps to 500 Kbps if the number
- of overrun errors on a track exceeds a threshold.
- Possible solutions:
- -------------------
- Some of the problems were solved by upgrading the (flash) bios.
- Other suggest that it has to do with the FDC being on the PCI
- bus, but that is not the case with the Intel Premiere II boards.
- [If upgrading the bios doesn't solve the problem you could try
- a floppy disk controller on the isa-bus].
- Here is a list of systems and recommended BIOS settings:
- Intel Premiere PCI (Revenge):
- Bios version 1.00.09.AF2 is reported to work.
- Intel Premiere PCI II (Plato):
- Bios version 1.00.10.AX1 and version 11 beta are ok.
- If using version 1.00.08.AX1, GAT must be disabled !
- ASUS PCI/I-SP3G:
- Preferred settings: ISA-GAT-mode : disabled
- DMA-linebuffer-mode : standard
- ISA-masterbuffer-mode : standard
- DELL Dimension XPS P90
- Bios version A2 is reported to be broken, while bios version A5 works.
- You can get a flash bios upgrade from http://www.dell.com
- To see if you're having the GAT problem, try making a backup
- under DOS. If it's very slow and often repositions you're
- probably having this problem.
- --//--
- LocalWords: ftape PCI bios GAT ISA DMA chipset Mbps Kbps FDC isa AF ok ASUS
- LocalWords: SP linebuffer masterbuffer XPS http www com
|
