[Coco] CoCo OS-9 CRC32, Was: Ambiguous code

[Stephen H. Fischer]

I was addressing the point that the checksum calculation was unsafe for many
uses. Use of checksums anywhere bothers me.

But possibly it is adequate for its intended use here.

Should it not be, that the CoCo (OS-9 at least In my experience), can check
the validity Of files transferred from other Computers and that the source
code for the CRC32 calculation is available for OS-9.

And that you can look at the CRC32 value generated by standard programs like
the various ZIP programs and compare it with a value calculated by an OS-9
program and feel safe that the files are identical.

I was investigating the possibility of locating identical files with
differing file names so they could be deleted.

SHF

----- Original Message ----- 
From: "Chuck Youse" <cyouse at serialtechnologies.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Thursday, September 25, 2008 2:42 PM
Subject: Re: [Coco] Ambiguous code


> On Thu, 2008-09-25 at 13:50 -0700, Stephen H. Fischer wrote:
>> Years ago I did some comparisons between the CRC32 values generated by
>> OS-9
>> and MSDOS for the same files.
>>
>> The code I had generated the same values. And matched other software
>> generated values from various MSDOS programs.
>>
>> This of course takes a lot more computing to generate than the checksum
>> calculation.
>>
>> Stephen H. Fischer
>
> Assuming you're using the same size CRC and same CRC polynomial, that's
> exactly what you would expect.  That doesn't have any bearing on the
> present conversation, though, unless I'm missing your point.
>
> C.