Relay-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site murdu.OZ Path: murdu!munnari!moncskermit!basser!elecvax!stephenf From: stephenf@elecvax.eecs.unsw.oz (Stephen Frede) Newsgroups: aus.sources Subject: PostScript printers in Australia Message-ID: <2802@elecvax.eecs.unsw.oz> Date: 16 Dec 86 09:37:21 GMT Date-Received: 16 Dec 86 14:01:54 GMT Organization: EE and CS, Uni of NSW, Sydney, Australia Lines: 534 Here is an article I have written regarding PostScript printers and laser printers in general. The only one I know of that is not in the article is DEC's printserver 40, which retails for $91 000, and for which I am getting more information. Apart from this I'd like any comments you have, or any extra information you have. In a while I will post a revised version of this to net.text, or whatever it is now. Oh yes, I have seen the articles on DDL and C-Pscript in "Desktop Publishing" and plan to incorporate that information, along with netnews gossip. ------------------------------------------------------------------------ PostScript printers - the state of the nation 1. Introduction Outlined here are the main features of the various PostScript printers available in Australia, along with miscellaneous comments. I believe everything here to be accurate and up to date as at November 1986, but take no responsibility for errors. 2. Marking engines All the printers here are laser printers, utilising basically the same technology, except for the Linotronics and Agfa-Gaevert, which are described later. Most laser printers are built around a "marking engine" of some sort, which is already available. Often there are photocopiers built around the same engines. It is these engines that determine the physical characteristics of the printer. All of the laser-printer marking engines described here provide a 300 dpi (dots per inch) resolution. The major difference between engines is their printing speed, measured in ppm (pages per minute). Basically, a laser scans a photosensitive drum, altering the charge on the drum. The drum then passes across toner, and picks it up, or doesn't, depending on the charge at that point on the drum. The toner is then deposited on paper, which goes under a fusing roller, so that the toner is melted onto the paper. The details of what charges go where are supremely unimportant, (in the canon engine, the drum and powder are both positively charged, with the laser discharging the areas where it strikes), however one aspect of the mechanism is relevant. Some engines are "write-black", which means that the toner is picked up wherever the laser has scanned the drum, whilst others are "write-white" which means that toner is picked up everywhere except where the laser has scanned the drum. There are two main results of this: 1. Because of charge leakage problems, a write-black engine does not produce very good large areas of black - they tend to be washed out. Write-white engines produce much better large black areas. The effect is not noticeable for normal text. 2. For engines of the same basic resolution, a write- white engine produces smaller dots, and thus finer lines than a write-black engine. This is because for - 1 - a given number of laser scans/cm, on a write-white engine, the black is appearing between the scans, which distance is less than the size of the beam-spot. At 300 dpi resolution, a line only 1 dot wide should ideally be 1/300 inch wide, but on a write-white machine it will be about 0.8 of this width, while on a write-black machine it will be about 1.2 times this width. This is not normally noticeable, but can produce problems with some fonts. For example, some metafont definitions need to know whether their output will be on a write-white or write-black printer. The circumference of the drum is in all cases less than the typical page length. Page width is limited by the engine, but page length is typically limited only by the controller (esp. memory capacity). 2.1 Canon 8ppm engine (Canon LBP-CX laser-xerographic engine) Probably the engine in the most widespread use. o Write-black o Resolution: 300 dpi o Max page width: ~215 mm (A4) o Duty cycle has been quoted between 1K and 5K pages/month, depending on who you ask. Apple recommend about 4K pages/month. o Engine life estimated at 100K pages. o Uses a replaceable cartridge which contains both toner and print drum, which means it's expensive (over A$100 for about 4K pages), but quality remains consistently high throughout the lifespan of the printer. o used in: LaserWriter, LaserWriter plus, QMS-PS800 and many non-PostScript printers, such as the Impact, Canon, etc. o input tray capacity: 100 sheets o output tray capacity: 20 sheets Many accessory devices are available for Canon engine based printers, including page-turners (so your output arrives page- down, in the correct order); large paper bins and - 2 - stackers, collaters, etc. UNSW Elec. Eng. have been running their Apple fairly hard for quite a while, and must be pretty close to the estimated engine life, but I believe that they are still going strong and havn't had any serious problems with their printer. Perhaps they'd like to comment. In the US, various organisations will refill your toner cartridge for a small fee. Apparently this can be done up to two times before quality becomes totally unacceptable. Discussion with various hackers leads me to believe that it can be done yourself if you know how, and are VERY careful. Also, it is essential to get the right type of plastic toner, or you may clag your printer forever. (Remember the imagen saga). 2.2 Toshiba_26ppm_engine o Write-white. o Replace drum every 100K pages. o Used in: Dataproducts LZR 2660/5 o Resolution: 300 dpi o Max page width: ~300mm (A3) o Input tray capacity: upper - 500 sheets; lower - 250 sheets Accessories available include face down output trays, 10-bin sorter/collaters and 1500-sheet feeders. 2.3 Ricoh_8ppm_engine o Resolution: 300 dpi o Duty Cycle: 10K pages/month o Rated engine life: 600K pages o Stacks face down (so your job comes out correctly ordered) o Input tray capacity: 250 sheets o Max page width: ~215mm (A4) - 3 - o Uses toner cartridges similar (identical?) to the canon engines. o Used in TI Omnilaser 2108 2.4 Ricoh_15ppm_engine As for the 8ppm, except: o Rumoured to be a "second generation" engine. o Duty Cycle: 25K pages/month o Rated engine life: 1.5M pages o Input tray capacity: two, each holding 250 sheets o Used in TI Omnilaser 2115 2.5 Xerox_12,_24ppm_engines o Resolution: 300 dpi o Used in QMS-PS1200/2400 3. Printers The marking engine is driven by a controller board, in these cases developed by Adobe, which provides the PostScript interface and does all the necessary image processing. Adobe have made substantial improvements to both their controllers and their firmware since the early ones. The most significant change to the firmware is evidenced between the Apple Revision 1 (PostScript version 23.0) and Revision 2 (PostScript version 38.0). The later version of PostScript includes additional features, allows handshake interpretation of DSR/DTR signals, as an alternative to XON/XOFF, allows transmission rates higher than 9600 baud, allows overlapping of page imaging with execution of the next page and is substantially faster overall. A document describing the changes was distributed over the net from Adobe and is available from Softway. Most printers come "standard" with the following Adobe fonts: Times, Helvetica and Courier (constant width) each in Roman, Italic (or at least oblique), Bold and Bold- Italic, as well as a symbol font. All the printers described here have both an RS-232 serial interface and an Appletalk (RS-422) interface, and provide a Diablo 630 emulation capability. Other interfaces - 4 - and emulations are noted below where they occur. 3.1 Apple_LaserWriter Certainly the most widespread of postscript devices. Uses the Canon 8ppm engine. Originally, used PostScript version 23.0, which had some (mostly documented) bugs and limitations. If you use this, make sure you have a copy of the software patch that fixes many of the bugs, and also a copy of the a4 page definition routine. Both of these were distributed over the net, and both are available from Softway. The LaserWriter includes the standard set of Adobe fonts. There are many satisfied LaserWriter customers, with very few complaints. However, if at all possible, you should try to get a Revision 2 LaserWriter, which is just a PROM upgrade to PostScript version 38.0. An Apple LaserWriter costs about A$8000 (inc. tax). Shopping around is advised. 3.2 Apple_LaserWriter_Plus This is solely a PROM upgrade to an ordinary LaserWriter. It gives you a Revision 2 LaserWriter (ie PostScript version 38.0) and a lot of extra fonts: Palatino, New Century Schoolbook, Avant Garde, Bookman, Helvetica Narrow and New Century Schoolbook, all in Roman (or Book, or Light), Bold (or Demi), Italic (or Oblique) and Bold-Italic (or whatever), as well as Zapf Chancery Medium Italic, and Zapf Dingbats. The upgrade to an ordinary Apple LaserWriter costs about A$1000 (inc. tax). If you have a Revision 1, it may be good value to go for the upgrade, because you will then have a Revision 2 printer. If you already have a Revision 2 printer, decide if you want to pay that much just for the extra fonts. Also note that it is very advisable to have this upgrade installed by a technician. The proms are VERY sensitive to static, and it is very important to allow a burn-in period before using the printer. If a technician installs the upgrade, you don't have as many hassles if things go wrong. 3.3 Sun_LaserWriter This is just an Apple LaserWriter, but it costs somewhat more because it comes bundled with some UNIX software. I havn't seen the software, but ours (Softway's) is almost certainly better. 3.4 QMS_PS-800 Very similar to the Apple LaserWriter Revision 2. Uses PostScript version 38.0. - 5 - 3.5 QMS_PS-1200,_2400 Use the xerox 12ppm and 24ppm engines respectively. I don't know any more about these printers. 3.6 Dataproducts_LZR2660/65 Uses the Toshiba 26ppm engine (a write-white engine) and PostScript version 39.0. The 2660 handles pages up to legal size, while the 2665 handles A3. Cost is ~$A40000. When we tested this printer, we found a PostScript bug which shows up under certain conditions. Adobe have been notified and are working on it. It uses the fastest engine on the market, but remember that it will not actually run at this speed unless you are doing multiple copies. The real win is in the A3 paper capability. It is the only PostScript laser printer I have heard of that will handle paper this size. We printed some very nice larger-than-life digitised images on this printer. 3.7 Apollo_Computer_Domain/Laser-26 This is just the Dataproducts printer descibed above. 3.8 TI_Omnilaser_2108 Uses the Ricoh 8ppm engine; has a page jogger (job separator); includes two font cartridge slots. Includes additional emulations: HP LaserJet/+, TI 855 DP/WP, HPGL (Hewlett Packard Graphics Language, used by most HP plotters). Includes additional centronics-type parallel interface. The cost is A$9990. Given the higher duty duty cycle and longer life, this printer sounds like it could very well give the Apple and other canon-engine based printers a run for their money. The face-down stacking and larger paper bins that come as standard are also useful, although these can be had as accessories on most other printers. 3.9 TI_Omnilaser_2115 This is the same as the 2108, but uses the Ricoh 15ppm engine, and has 3Mb RAM. The cost is $14500. Again, this sounds like good value for money for a faster printer. 3.10 Agfa-Gaevert_P400-PS This printer uses LED array electro-photographic imaging, rather than the more conventional laser scan, and has a resolution of 406 dpi. The controller is a 68020 based 'Atlas' controller, which includes a 1Mb font cache (by far the slowest part of printing on PostScript printers is cacheing characters), two 2Mb memory (whatever that - 6 - means), and a 20 Mb hard disk. The engine speed is 16ppm and apparently the controller usually manages to drive it that fast. Comes with two paper bins, one of which holds 2000 sheets, and a face-down output stacker. Interfaces additionally include a centronics-type parallel connection. Sounds like a really nice machine, but unfortunately Agfa-Gaevert in Australia say they don't even have pre- release information on it, and that it will probably arrive in Australia the middle of 1987. The cost is ~180K Francs (US$28K). Note that the P400-PS, although using the same marking technology as the earlier P400, has a completely different controller. Apparently the previous command language was horrible and full of bugs. They won't even upgrade a P400 to a P400-PS because there are too many differences. Also, the P400-PS is cheaper then the P400. Delairco_Linotype_Linotronic_series The Linotronic machines are not so much laser printers as phototypesetters. Linotype advertise them as "laser- setters", which is an apt name, because a scanning laser beam images directly onto photographic film, or light- sensitive paper. They feed from continuous rolls rather than cut-sheet. Available as options are hard disks for font storage (the entire Mergenthaler font library is available on an 86 Mb winchester), and high-speed options. I forget exactly which version of PostScript they use, but it is a recent one, around 39.0. Bureau services are available which will print stuff on these machines from PostScript (that you have presumably generated from a Mac or software from Softway). 3.11 Linotype_Linotronic_100 Resolution of up to 1270 dpi; additional centronics interface; standard PostScript fonts; 17Mb (formatted) hard disk. Print speed is up to 240 lines/minute. Cost is A$69250. 3.12 Linotype_Linotronic_300 Resolution up to 2400 dpi; paper width up to 305 mm wide (A3); print speed up to 585 mm/minute. Cost is ~A$96K. 3.13 Linotype_Linotronic_500 Resolution up to ~1500 dpi; paper width up to 457 mm wide (newspaper size); print speed up to 1040 mm/minute. Cost is > A$100K. - 7 - Random_notes_and_rumours I have heard that an upgrade for canon engines is under development, whereby the photodiode that produces the laser is replaced, to increase the possible resolution to 400 or even 600 dpi. However, apparently the main problem is that the fine grade of toner that is required for such resolution leaks out of existing seals. Group IV Fax is defined as having a resolution of 400 dpi. If anyone has any extra information about any sort of laser printers, especially those with high-level input languages, or has any comments on the information in this document, I would appreciate hearing about it. Stephen Frede Softway Pty Ltd P.O. Box 305 Strawberry Hills NSW 2012 AUSTRALIA Phone: (02) 698 2322 ACSnet: stephenf@gris.oz - 8 -