[sebhc] list archive and a specific question

[Dwight K. Elvey]

Hi Dave
 If you are seeing errors, you have some type of
issue that needs to be fixed. Are you using the
checksum directly from the sectors on the disk
( may be a CRC ) or are you generating it from
a RAM buffer? Like I said, I've never seen a problem
without a cause. I have designed embedded systems
that do CRC checking on packets of data that
run continuously, 24/7. Any logged errors required
repairs. I've, also, done over a 100 disks on my Poly8813 without
a single missmatch.
 In any case, you should try using a CRC rather than
a check sum. These can be used to find the error location
for small burst of bit errors. I would suspect your RAM
if the errors were always in the same location of your
buffer. As a sanity check, you might try turning on
the parity as well.
 Of course, if you are using Windows, such errors are normal.
Dwight

>From: "Dave Dunfield" <dave04a at dunfield.com>
>
>
>> I thought I'd mention, I don't do checksum. My experience with
>>serial is that it is either working or it is not working.
>
>I've been slowly "mining" a box of about 1000 NorthStar disks...
>So the Vector is often sitting here sucking on a diskette and
>sending it up to the PC. My PC software tells me when it gets a
>soft communications error (checksum failure), and I do see them
>occuring from time to time - often enough that I would not want
>to ignore the possibility.
>
>Regards,
>Dave
>-- 
>dave04a (at)    Dave Dunfield
>dunfield (dot)  Firmware development services & tools: www.dunfield.com
>com             Collector of vintage computing equipment:
>                http://www.parse.com/~ddunfield/museum/index.html
>
>
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