You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
82 lines
2.8 KiB
82 lines
2.8 KiB
20 years ago
|
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
|