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-
- Contents:
- =========
-
- * General purpose printer definitions.
- * Using "Top_Left" to calibrate your printer
- paper offsets.
- * Print density variation from RISC OS 2.
-
-
- General purpose printer definitions
- ---------------------------------------------------------
- The "Text" printer definition file is a very basic
- raw text printer definition file. It assumes
- virtually nothing - it uses form-feed (12)
- carriage-return (13) and line-feed (10) and the
- normal ASCII printable characters from 32 to 127.
- There are text highlights. ISO Latin 1
- international character mappings are supplied, but
- every character is simply mapped to the closest
- available normal ASCII character.
-
- You would only use this file when attaching an
- unusual printer for the purposes of doing text
- printing only eg. daisy wheel printers, golf ball
- printers, line printers etc.
-
- The graphics resolution in this file is a dummy as
- all DP printers must have at least one graphics
- resolution. (It is in fact an MX-80 Type II
- resolution).
-
- The "PostScript" printer definition file should be
- used if you cannot find a definition file for your
- PostScript printer.
-
- It defines a colour PostScript printer with a
- resolution of 300 by 300 dpi, with the standard 35
- fonts that Adobe provides.
-
- The "PstScrptFP" printer definition file should be
- used if you have a PostScript printer with a fast
- parallel interface and your computer has suitable
- hardware. In all other respects, it is identical
- to the "PostScript" printer defintion file.
-
-
- Using "Top_Left" to calibrate your printer paper
- offsets.
- ---------------------------------------------------------
- The "Printers.Top_Left" printout file can be used
- to calibrate the position of output on Epson and
- IBM compatible dot matrix printers. To do this,
- you should first ensure your printer is in its
- default state eg. switch it off and switch it back
- on again, and feed paper into it if necessary.
- Then send the Top_Left file directly to the
- printer. The easiest way to do this is to set
- !Printers up for printing to your printer, and
- then drag the "Top_Left" file icon onto the icon
- for your printer on the icon bar. Alternatively,
- you can use the command line; the command "*Copy
- Top_Left Printer:" will send the file to the
- printer, assuming you are in the Printers
- directory and the print destination has already
- been set up correctly (eg. by !Printers).
-
- On the paper there should be a small vertical and
- horizontal line (like an inverted "L") close to
- the top left corner of the paper. Start !PrintEdit
- (in App1) and drag the printer definition file you
- wish to use into the !PrintEdit window. Measure
- the distance from the left hand edge of the paper
- to the left hand edge of the inverted "L" mark (do
- not measure to the middle of the mark). The
- distance you have just measured is the "Paper X
- offset" for your printer, so you should enter it
- into the "Paper X offset:" field in the !PrintEdit
- window. Now measure the distance from the top of
- the paper to the top edge of the inverted "L" mark
- (again do not measure to the middle of the mark).
- This distance is the "Paper Y offset" for your
- printer, and should also be entered in the
- !PrintEdit window. Now click the MENU button in
- the !PrintEdit window (avoiding the "Graphics
- modes:" icons or you will get the wrong menu), and
- use the "Save" option to save your customised
- printer definition file. It is recommended that
- you do not overwrite your master printer
- definition file. Either make sure you have
- backups, or save your new file somewhere else.
-
- Now quit !Printers, restart it, and load in your
- new printer definition file using the "Printer
- control" window. Printed output on your printer
- should now appear in the correct position.
-
-
- Print density variation from RISC OS 2.
- ---------------------------------------
-
- You may find that printouts are lighter or darker
- under RISC OS 3 than they were in RISC OS 2. This
- is usually due to a change in the amount of
- interlacing being performed ie. the number of
- passes the print head makes over the same section
- of the paper.
-
- For example a Canon BJ-300 printer under RISC OS 2
- with !PrinterDM set to "EPSON LQ-850 compatible
- (360 by 360 dpi)" and the printer set to Epson LQ
- emulation mode will make two passes over the paper
- due to using vertical interlacing. The same
- printer under RISC OS 3 with !Printers using the
- Canon.BubbleJet file set to 360 by 360 DPI and the
- printer set to IBM emulation mode will only make
- one pass over the paper. So the printout will be
- lighter, but on the other hand it will take less
- time to print and the quality will be higher since
- no interlacing is being used. Also the ink
- cartridge will last longer. In this example
- running the printer in Epson LQ emulation mode
- with the Epson.LQ-860 file set to 180 by 360 DPI
- will give results which are almost identical to
- the RISC OS 2 configuration.
-
- In the general case, if you use 360 by 360 DPI in
- any printer definition file which gives true 360
- DPI vertical resolution (non-interlaced), then
- this will give lighter print than any of the 360
- by 360 DPI standard Acorn !PrinterDM settings,
- which are all interlaced. The files which use true
- 360 DPI vertical resolution are Canon.BJ-130e,
- Canon.BJC-800 (usable with Star SJ-48) and
- Canon.BJ-130e. Switch to a 180 by 360 DPI
- resolution in a more standard file (eg.
- Epson.LQ-860) if you need the interlacing to get
- darker print.
-
- Conversely take an Epson LQ-850 printer under RISC
- OS 2 with !PrinterDM set to "EPSON LQ-850
- compatible (360 by 360 dpi)". This again will make
- two passes over the paper. The same printer under
- RISC OS 3 with !Printers using the Epson.LQ-860
- file set to 360 by 360 DPI will make four passes
- over the paper since it is now horizontally
- interlaced as well as vertically interlaced. (In
- fact RISC OS 2 never really achieved 360 DPI
- horizontal resolution since it didn't interlace it
- and the printer will not print adjacent dots. The
- only benefit this gave was 360 DPI positional
- accuracy of left hand edges.) So the printout will
- be darker and the resolution will be better, but
- on the other hand it will take longer to print and
- will wear the ribbon out faster. In this
- particular example using 180 by 360 DPI in
- !Printers will give results which are almost
- identical to the RISC OS 2 configuration.
-
- In the general case, if you use any resolution in
- any printer definition file which is horizontally
- interlaced, this will give darker print than the
- same resolution under !PrinterDM. In practice this
- is 240 DPI horizontal for 9 pin printers (240 by
- 72, 240 by 144 and 240 by 216) and 360 DPI
- horizontal for 24 pin printers (360 by 180 and 360
- by 360) although not all of these resolutions are
- available as standard in !PrinterDM. If you need
- to get the same print density as you did on RISC
- OS 2, halve the horizontal resolution you are
- using to 120 DPI or 180 DPI. If the extra
- positional accuracy of left hand edges that RISC
- OS 2 gave you turns out to be important, then edit
- the horizontally interlaced graphics resolution
- you are using (eg. 240 by 216) with !PrintEdit and
- change the "X interlace:" field from 1 to 0 which
- will disable the horizontal interlacing. (Note
- that you cannot simply disable vertical
- interlacing in a similar manner. Other changes
- would be required.)
-