laser-lovers@uw-beaver (02/08/85)
From: Scott Jones <saj@MIT-PREP.ARPA> [[Editor's note. This message is in response to a request, not forwarded to the list as a whole, for information on the LN01 and LN01S. --Rick]] In response to your request for an evaluation of the LN01/LN01S, I can only evaluate the LN01S. I will compare it with a similar but superior printer, the QMS 1200/2400. We have one of the first LN01S models. We never had an LN01. The difference between the two is that the LN01S can support INCREMENTAL downloading of fonts (which means you can *append* a new font description to the printer's font table). The LN01 wants all the fonts downloaded at once. If you need a new font, you have to throw away all existing fonts in the LN01 memory and do another download. With the LN01S you don't have to throw out existing fonts until font memory fills up (which usually turns out to be around the 15th to 25th font). This is still not the "right way" to do things. One should be able to dynamically swap fonts in/out of the printer's memory so that a reasonable allocation algorithm can be used from the driver (an LRU algorithm probably). I think the only other difference between the LN01 and the LN01S is that the LN01S can hold up to 96 soft fonts (22 for LN01) in addition to its 12 fonts in ROM (2 for LN01). Unfortunately, the typical font is about 20k so you run out of font memory with about 20 fonts since there is ~400k of font RAM in the LN01S. The quality of the fonts in ROM is okay. They are generic fixed width fonts... adequate for program printouts. We use Tex, Scribe, or R to get fancier fonts, but that is not a printer dependent issue. The laser engine prints at 300 dpi so the print quality is reasonable. It's still not typesetter quality, but I don't know of any laser printer that is better (not even our DOVER at ~400 dpi). The contrast of the image is excellent even when there are large solid black areas. When adjusted correctly (which isn't hard), this printer gives very nice clean, crisp, clear black-on-white print every time. Fine detail (5pt fonts, thin lines in graphics) as well as large splotches of dark are impressive. Halftones look good too. I should remind you that the print quality comes from the quality of the laser engine and not the controller. Other companies use the same laser engine with different controllers. It turns out that QMS uses the same laser engine by no mere coincidence. The DEC LN01S *is* a QMS 1200 with new firmware (less functional, still more bugs) in the controller. The controller boards in the LN01S are labelled "QMS", but the firmware and font ROMs are labeled "DEC". So why did we buy the DEC LN01S as opposed to the QMS 1200? Ignorance. We are planning to buy at least 3 QMS 2400's this spring, and we would like to convert our LN01S back into a QMS 1200. One of the features that was missing from the LN01S which is mandatory for our lab is the ability to do full bit-map downloads. Since the LN01S couldn't do it directly, I put together a filter which does the right thing by using a simple 7x1 bit font and uses some smarts to shorten the transmission time. The QMS printers support full bit-map downloads with data compaction. You asked about UNIX support. Unfortunately, DEC still pretends not to know that UNIX exists. There is absolutely NO UNIX support from DEC for the LN01S. It turns out that everything you need is in the public domain... but still, it's a little discomforting to know that DEC won't provide this support. Luckily, Sam Bent (Wisconsin) had done a TeX driver for the LN01 which got us started. I also had to make some modifications to the standard 4.2BSD lp driver in the kernel so that characters were not interpreted in the driver. DEC also does not support TeX, Scribe, or R. As far as I know, they don't sell extra fonts either. QMS does provide UNIX 4.2 support, TeX support, Scribe support, etc... (call them for more info). A gripe that I have with both the DEC LN01S and the QMS 1200 is that the paper trays are so small. They must be constantly (it seems) refilled. There are two trays which each hold 250 pages. At 10-12 pages/minute, it only takes about an hour for both trays to empty. The QMS 2400 appears to be wonderful (I saw the one at BBN), not only because it prints twice as fast, but also because it has a side mounted paper feeder which is easy to load and holds 2000 sheets (in addition to the 500 page capacity paper trays on the front). Kudos to QMS. Our LN01S cannot be considered "reliable" because it frequently shuts itself off and never wakes up again. Also, there are font download situations which cause the LN01S to lose completely. I think all of the remaining problems can be attributed to the DEC firmware in the controller because the LN01S IS reliable in the sense that it hardly ever paper jams and it usually prints a good image when it's printing. My understanding is that the QMS printers at BBN are running constantly with very few reliability problems. As for service/repairs, DEC service engineers know very little about the LN01S. Service is sometimes hard to get because they have to send out someone who is "specially trained to work on laser printers". We've had at least 3 of these specially-trained persons, each of whom has said they'd "never seen one of these before"! So I showed them how it worked and how to hook up a diagnostics terminal (which was of no use to them). About the best that they could do was board swapping which didn't solve the firmware problems so I got in touch with the division in DEC which put together the LN01S firmware. They were very nice/helpful. They provided the necessary documentation over the phone to get our LN01S up & running (see next paragraph). I even pointed out a few bugs which they went off to fix. We have yet to get new firmware though and so in its existing condition, I cannot favorably recommend the LN01S to anyone. The quality and quantity of documentation for any laser printer on the market today should be a key purchasing factor. If you compare the DEC and QMS documentation, you will find that QMS wins hands down. The LN01S doc is simply a few addendum pages to the LN01 doc (which was not very high quality in the first place). I could not find LN01S documentation for things like DIP switch settings on the controller board (which were set incorrectly for our configuration) nor could I find complete specifications of the error/status codes. DEC also does not tell you the font format or what sixel encoding is all about (even though they refer to it in a non-existent appendix). Flame flame. QMS sent me a copy of their manual which is much more comprehensive and of much higher quality. Unfortunately, I have not had to program for the QMS printer so I haven't had to put their manual to the acid test (yet). As for pricing, the list price for the QMS 1200 and the DEC LN01S are comparable. In my opinion, you get much more for your money with the QMS though because of the additional functionality, etc. The list price of the QMS 2400 is about $10k more. There is also a QMS 800 for low-volume applications which sells for about $10k I think. Because we are an educational institution, we don't have to pay list price for either the DEC or the QMS, but I'd rather quote you the exact figures over the phone... or you can just call DEC or QMS yourself and work out a deal. Hope this helps... --Scott Jones
laser-lovers@uw-beaver (02/09/85)
From: MBartulis.ES@XEROX.ARPA Scott, The DEC sales literature leads one to believe that one can do full bit-map downloads to a LN01S. Your message stated that the LN01S could not. Are you saying that the featue is not implemented or dosen't work or that the sales literature is wrong and it dosen't do it. Thanks Mike Bartulis Xerox - Printing Systems Division
laser-lovers@uw-beaver (02/09/85)
From: Scott Jones <saj@MIT-PREP.ARPA> The LN01S most definitely does not support full bit-map downloads. The sales literature is completely bogus. The QMS 1200 does support bit-map downloads. DEC removed this functionality when they rewrote the firmware. I asked if the functionality would be present in the future and they seemed to think it would (although not immediately). --Scott Jones PS: BTW, my kludge to provide full bit-map downloads seems to be at least as fast as what QMS provides. My method could probably be implemented on any laser printer that supports downloading of fonts.
laser-lovers@uw-beaver (02/10/85)
From: Robert Morris <ram%vax2.uucp%umass-boston.csnet@csnet-relay.arpa> The claim that DEC still pretends UNIX doesn't exist is a strange one, since they sell ULTRIX, a supported(?) Unix for VAX's and I believe for PDP-11's. Perhaps someone who has ULTRIX could comment on whether troff with LN-xx support is part of it and how it works.
laser-lovers@uw-beaver (02/10/85)
From: dave@wisc-rsch.arpa (Dave Cohrs) Mike Bartulis writes: > The DEC sales literature leads one to believe that one can do full > bit-map downloads to a LN01S. Your message stated that the LN01S could > not. Are you saying that the featue is not implemented or dosen't work > or that the sales literature is wrong and it dosen't do it. We have an LN01S. It does NOT download bitmaps. The liturature is wrong. This feature is not part of the LN01S (how I wish it were!). Does anyone know if DEC plans on adding this feature to the LN01S (an upgrade, possibly?). Scott's evaluation seems very valid to me. What's really sad is knowing the capabilities of the LN01S, and seeing wonderful things being printed on our 2700s (connected to Xerox workstations only). The same print-engine, but oh, how the DEC firmware is lacking! ---- Dave Cohrs ...!{allegra,harvard,ihnp4,seismo}!uwvax!dave dave@wisc-rsch.arpa (Bug? What bug? That's a feature!)