Newsgroups: comp.sys.transputer
From: emil@aplcenmp.apl.jhu.edu (Emil J. Hatfalvi)
Subject: Re: network booting problem with iserver
Organization: Johns Hopkins Continuing Professional Programs
Date: Tue, 25 Oct 1994 22:07:25 GMT
Message-ID: <Cy91GE.F7r@aplcenmp.apl.jhu.edu>

andyr@teal.csn.org (Andy Rabagliati) writes:

>[ reposted - newsfeed problems. My apologies ]

>Henno Tillema <tillema@cs.utwente.nl> wrote:
>>
>>We have a major problem with the iserver booting a network:
>>
>>Sometimes when we try to boot our transputer network the iserver
>>stops sending the bootfile into the network with the message:
>>       Error - iserver - unable to write byte # to the boot link


>>a post-mortem inspection with the debugger shows all transputers
>>still in an invalid state for the debugger:
>>-Iptr in Stack area or in Vectorspace, Wdesc is NotProcess

>What state are the links in ?

From our experience, the problem is NOT always the links....

The original iserver (which you probably have source for) had a
very STUPID for (i=0; i<1000000; i++), or some such "timing" loop.

If the transputer farm failed to download any chunk of the image when
that "timer" had expired, it would declare that it was unable to boot.
This worked with many older (read "slower") machines, but dies an
ugly death with anything faster than an 386/33.  Some solutions:
	1) see if this is really the problem by slowing down the host
	  (e.g. turn off turbo, etc, if PC)
	2) or, get the updated iserver from your vendor.

This timing loop was also used, if I remember correctly, to time
the holding down (or up) of RESET!   Again, a problem waiting to 
happen.

We fixed this in our version of the iserver, but it is only for DOS, and
I don't know what version you are running, so I hesitate to volunteer it.
However, this may put you on the right track..

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Emil J. Hatfalvi               |"No one is totally useless... They can always
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