AT&T 6300+ add-in disk problem!

[John A. Frieman]

> I have found that I can only go as low as a 5:1 interleave with my 6300.
> That's horrible!  I only get about 85KB/sec xfer rate which is pathetic.
> I'm using a WD XT-GEN controller, but the default DTC controller was no
> better.  I guess the I/O on a 6300 is WORSE than an IBM XT...
> 
> I used the SPINTEST demo program available on SIMTEL-20 and the HDTEST program
> to determine the above.  You might try the same.
> 
> Rich Gopstein

I have a 6300+ at home and another here at the Lab, both run with an
interleave of 3:1.  Both have WD controllers and 20 Meg. drives (1 ST-225
and 1 Olivetti both rated at 65 MS seek times).  It's been a while since I 
ran any disk benchmarks but a transfer rate in the 300-400 kb/sec seems about 
right.  The 6300+ has a DMA accelerator for hard disk access.  The design for 
this is published by INTEL with the DMA chip spec., but I haven't seen it used 
by anyone else.

Once you sort out the interleave you might find a copy of QFRESH on a local
BBS.  This little (15 bytes) gem reduces the number of DRAM refreshs to a
workable level.  My system picked up 8% on a memory intensive program with
QFRESH in the autoexec.bat.

Enjoy,
John A. Frieman, AGS Info Srv, @AT&T Bell Labs, Denver
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