>From dl.c (Desklink for Unix):
if(st.st_size>65535)
{
normal_return (0x6E); // file too long error
break;
}
So the 64K-1 limit is no surprise.
On Sat, Feb 25, 2017 at 4:55 PM, Brian White <[email protected]> wrote:
> Random model 600 discoveries while trying to test the new ram boards more
> rigorously.
>
> Idea was to:
>
> Populate both slots, which makes a little over 220k available.
>
> Generate about 256k of random binary data on a modern machine. I just copied
> 256k of random stuff and used gpg on it a few times randomize it thoroughly.
>
> Xmodem the blob to the 600 until it aborts.
>
> Xmodem the blob back to the pc.
>
> Use dd to copy out a truncated excerpt from the original blob of exactly the
> same size as the blob that came back from the 600.
>
> Binary compare the two truncated blobs.
>
>
> I encountered 2 things:
>
> You can't xmodem more than 64k in one file.
>
> So I split the 256k blob into 4 64k blobs and discovered the next thing.
>
> You can't *actually* xmodem more than 64k *minus one byte*, in a single
> file.
>
> If you try to send a file over 64k and allow telcom to truncate it at 64k,
> or if you try to send a file that is exactly 65536 bytes, you will transfer
> 65536 bytes both ways, and neither side of the connection will issue any
> warnings or errors. Both TELCOM and the xmodem util on the modern machine
> will say everything went fine. But if you transfer a 65536 byte file from a
> pc, to the 600, and back, the final byte will be changed from whatever it
> was to a 0x20 space. All other bytes are preserved.
>
> If you transfer a file 65535 bytes or less, the file makes it both ways 100%
> accurate.
>
> I don't yet know when the change takes place. Is it when telcom receives the
> file from the pc, or when telcom sends the file to the pc? Both? There are a
> few ways to test the individual parts, just it's soooo sloooow. It takes
> about 10 minutes to transfer 64k.
>
> I think this mostly proves out the ram boards, as well as can be without an
> actual ram test program. To really be sure, I should swap the 2 boards
> between slots 1 & 2, and repeat the whole process. Ugh.
>
> --
> bkw
--
Ron Lauzon - rlauzon at acm dot org
Homepage: http://webpages.charter.net/rlauzon/
Weblog: http://ronsapartment.blogspot.com/
DNRC: Lord of All Things That Are Fattening
"To be sure, conservative radio talk show hosts have a built-in
audience unavailable to liberals: People driving cars to some
sort of job." - Ann Coulter
Microsoft Free since July 06, 2001
Running Ubuntu 16.04
