Hi,
Would it be okay to write to a DOS drive real-time?
Are there any issues with using the Fatfsys driver for writing data
real-time? In another words, does the use of the Fatfsys driver cause any
problems with interrupt latency, etc…
We would be writing variable block sizes (1k - 32k) at a maximum of say
100-150 Kb/s using IDE hard drive.
TIA
Augie
“Augie Henriques” <augiehenriques@hotmail.com> wrote in message
news:9ks5qv$4os$1@inn.qnx.com…
Hi,
Would it be okay to write to a DOS drive real-time?
Are there any issues with using the Fatfsys driver for writing data
real-time? In another words, does the use of the Fatfsys driver cause any
problems with interrupt latency, etc…
From experience no.
However FAT is far less robust then QNX4 fsys.
We would be writing variable block sizes (1k - 32k) at a maximum of say
100-150 Kb/s using IDE hard drive.TIA
Augie
Augie Henriques <augiehenriques@hotmail.com> wrote:
Hi,
Would it be okay to write to a DOS drive real-time?
It is not intended for such use.
Are there any issues with using the Fatfsys driver for writing data
real-time? In another words, does the use of the Fatfsys driver cause any
problems with interrupt latency, etc…
It goes through the regular Fsys drivers for hardware access – it
essentially does block_read/block_write to deal with the raw partition.
So, you’ll get any issues you’d get from any other Fsys driver. Don’t
talk to a floppy.
We would be writing variable block sizes (1k - 32k) at a maximum of say
100-150 Kb/s using IDE hard drive.
You should be ok with this, the main issue is resiliency. You won’t
get the same resiliency and repairability that you get from the QNX4
file system, so will have to be extra careful to avoid unexpected loss
of power, especially as QNX does not have a file system integrity
checker/repair software for DOS file systems.
QNX Training Services
dagibbs@qnx.com