alo@kampi.hut.fi (Antti Louko) (05/17/91)
Digital PrintServer 20 Saga: My original intention was to post following article at March 1991. After discussing with local DEC support, I decided to wait and see what happens. I have added comments [] about the current sitation. Most of the problems has been acknowledged. But DEC has not been able to ship any newer version. ---------------------------------------------------------------------- We have had problems with out DEC Printserver 20 since we got it in April 1990. We use it with TCP/IP software and don't want to use Ultrix supporting host. This means that we cannot use the latest version of supporting host software because it needs Ultrix 4.x. [The new software version refers to unofficial test release of the LPS software] Here is the list of problems I have reported to DEC: - LPS20 doesn't show if it is asking with bootp, getting image with tftp. It is impossible to know if something went wrong or what it was. [This seems to been fixed. DEC installed a newer controller board and LPS20 seems to boot well now.] - LPS20 sends numerous bootp requests during a few seconds. If the server machine fails to answer, LPS20 apparently never sends further requests. It is necessary to reboot LPS20. - Sometimes LPS20 fails to receive image with tftp. It doesn't however tell what went wrong. Neither it tries again itself. Again, it is necessary to reboot with POWER OFF/ON sequence. [ Previous two problem were resolved in September 1990 after a local DEC engineer told us that LPS20 needs SQE test (aka Heartbeat) from its tranceiver. This fact is not documented anywhere in manuals (4 of them)] - PostScript "print" operator doesn't function properly. If PS program doesn't "flush" the output queue, LPS20 loses about 380 out of each 512 characters it sends back. Apparently LPS20 uses 512-byte automatic buffering. It however sends only the first 120 characters of each buffer. [ Doing this continously hangs the printer eventually. This bug means that any user can crash the LPS20 by sending a suitable PostScript job to the printer. ] - Sometimes, when aborting jobs from lprc program, LPS20 crashes. It says: "Please reboot or power cycle". Sometimes it just says "Ready" but refuses any TCP connections. - Sometimes, after booting, LPS20 says "Ready", but doesn't answer pings or accept TCP connections. TCP connections stay in SUN_SENT state. Apparently LPS20's IP and TCP are not up. [ This is caused by the feature that LPS20 doesn't respond to pings and bootpd supplied with source kit puts arp info without permanent flag. We put a hourly script in /usr/lib/crontab which puts lps address in the arp cache. ] - Is it possible to open files in UNIX machine's file system (given with -F flag to lpad) from PostScript program? If it is, how? [ According to a person who was designing LPS40 TCP/IP software this worked in LPS40 and he wondered why it doesn't work in LPS20. This feature is needed if we want to store demand-loadable fonts in the disk of the supporting host. ] [ I have received information that this feature is not supported in the new version either. In my opinion, this is bad. It is silly if a printer connected to fast network has to keep all resources in its RAM. ] In May 1990 my questions were forwarded to the head of software engineering had agreed to answer them. After this I got involved in other projects and LPS20 crawled several months. In September I started again asking if these problems could get fixed. This time I tried with Finnish Digital. Several persons at DEC got involved and the previously mentioned engineer fixed some problems. He took some network dumps and sent them to the engineering group (I guess). He also said that they would probably be rather busy and it would take some time to process all the data. In November I heard that there would be a new release coming soon. Last week [ In the end of February 1990] I started again pinging Finnish DEC with this problem. I asked them to send queries again to the engineering and that I would like the answers to my original questions. (Otherwise, how would I know if DEC considers them bugs or features.) Last Monday March 4. this DEC engineer called me and told that we could try the new not yet released version. Unfortunately this kit doesn't have sources for supporting host programs (lpsad, lpsrc etc.) and we are therefore out of luck because the management protocol has been changed and the old programs don't work. I have also reported about the untrue specifications of LPS20. User maintenance should be needed after about 20000 pages. Our LPS20 has needed user maintenance after 10000 pages. Because of numerous paper jams, drum has damaged and we have gad to replace it twice. First time, however, DEC changed it for free. Estimated maintenance costs are not at all what we calculated from the data given by the sales representative. [ DEC has admitted that their original estimation about maintenance interval is incorrect. Our sales person has agreed to compensate this at a time suitable for us. ] I have now waited too long. DEC hasn't kept their promise to answer my questions. [ After DEC Finland put this thing into high priority, the ansers started to drop. Before that, LPS20 engineering group was a black hole. ] What should I do to get working software for out printer? I hope this posting helps us to get everything working well. But it is not a good business practise to let customer wait this long without letting know what is getting fixed and when. [ I should have probably sent this two months ago. ] I don't have any trust to DEC anymore and as far as I can affect, we don't buy anything from them before they have explained why this whole thing failed. [ This was my feeling then. I still want a good explanation why a product which has serious bugs has update interval of over one YEAR. Besides, it would give a good impression to aknowledge bug reports without putting the whole thing to the top priority. ] Antti Louko (alo@hut.fi) Helsinki University of Technology Computing Centre Otakaari 1 SF-02150, Espoo FINLAND tel. work +358 0 4514314 telefax +358 0 464788