NP> I get CRC errors occasionally when calling Paul.

RS> Presumably you mean you see those on the ZedZap status
RS> screen thats up during the actual transfer of the file.

NP> That's what I am talking about.  CRC error at 25198
NP>                                  CRC error at 47910....etc

NP> They chances of their appearance depends on Who I am calling.
NP> From Teddy (same exchange) 4 crc errors in 90k
NP> From Brisbane             no crc errors in 2.8 MEG

Thats interesting. Corse its possible that its just Teddys
system thats fucking up too, not yours. You would think that
it would be yours since you see the problem with others tho.

NP> It appears to be WHO I call

Which also supports the proposition that its them. Particularly when
Paul now says they appear to have gone from his callers now. Are you
still getting CRC errors with Paul now that he has upgraded Bink ?

RS> Are you saying you get them even with plain old single tasking DOS ?

NP> YEP !!!

NP> Using BNU locked at either 19200 or 38400 makes no difference.
NP> USR sportshoe 14400 aka BV
NP> LAPM V42bis

RS> If you are on the edge of an interrupt latency problem, you can get
RS> the illusion that the type of call is important, but its just because
RS> the time between bytes changes with the speed of the modem at the
RS> other end of the call and the LAPM block size etc stuff achieved.

NP> Block size goes up  1024 2048 4096 8192
NP> Then CRC error at xxxxx
NP> Block size the drops 512 for a wile and then slowly climbs up again.
NP> Next error repeat performance.

I was talking about the block size at the LAPM level, not the ZedZap level.
Its not that easy to see what you have achieved in a particular connect
on block sizes at the LAPM level, whats been negotiated between the modems.

NP> Down here, it appears to be more of a line problem
NP> than an operating system problem

RS> It shouldnt be if you achieving LAPM or MNP4 sessions. That error
RS> correction should be complete transparent between the modems and you
RS> shouldnt see any CRC errors at the file transfer protocol level at all.

NP> They show, and the worst one at the moment is Teddy  six houses away

Yes, but we dont know that thats due to LINE ERRORS. The should be being
transparently fixed between the modems by the LAPM error correction and
not visible as CRC errors on the ZedZap status screen at al.

RS> Corse I am assuming you have the 16550 already too.

NP> Doesn't the sportshoe internal have it own? or a virtual one oe sumfin?

Its got a real one, you can see it on the board.

NP> Anyway ... All 4 com ports have 16550's

Yeah, cant be that. There is a slight possibility that you have
an interrupt latency problem due to a cache particularly, but that
shouldnt normally give varying results depending on who you call.

Looks more likely it the system you are calling with the problem. And
pretty convincing evidence if you no longer get CRC errors with Paul.
@EOT:

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