Hi Eric, it is not confusing; I got the idea. Thanks! :-)
I just read a PDF file "Epson ESC/P Reference Manual". It explains that 24-pin printers can "receive" definitions on 241 characters into its RAM but those 9-pin LX printers cannot. They can only receive 6 characters. It seems that uploading a codepage into a printer's RAM is out of the question. :-( Perhaps the idea (which is what I did once with a 9-pin Epson LX-800 that I had) is to manipulate the printer head directly. That would leave CPI files and hardcoded printer codepages out of the equation. That would force me to manually provide the data (through a TXT file) which would be sent to a printer through some program which would pose as a "printer driver". I would like to elaborate more on this but it seems this is the wrong freedos-list to do that. I have some ideas and perhaps we could work together on a "printer driver" for FreeDOS. We could start e-mailing each other directly to discuss that. What do you say? Regards, Henrique Em 5/5/2011 04:57, Eric Auer escreveu: > Hi Henrique, > >> If I understood you correctly, by using FreeDOS GRAPHICS, I could send >> a codepage directly to the printer's RAM (naturally, one which wasn't >> already hardcoded into it). Am I right? It would be great. > No. You could print a screenshot of DOS showing text in some > (possibly user-defined, with some codepage) as a picture, as > graphics. That only works if you switched to a GRAPHICS mode > first and if our DISPLAY driver makes sure that your custom > font is used there (as opposed to only in text modes where > the VGA hardware does the font handling). However, it shows > the general idea. > > I believe Aitor also wrote some tool long ago which works > similar but for hardware TEXT modes: The tool reads the VGA > hardware font and uses that when printing the text that you > see on the screen in text mode, printing a picture of that. > If you use DISPLAY to load a custom codepage, the VGA font > in hardware will be the font loaded from your codepage then. > > A third tool would be one which reads a text FILE or poses > as a DOS printer device (like PRN or LPT1 etc) but then does > not print the text as text. Instead, it would read the font > of a codepage of your choice and send a picture of the text > in that codepage font to your printer. > > While I am not aware of a nice implementation of this idea, > I once wrote a similar driver which hooked LPTn+1 (where n > is the number of real printer ports that you have) and made > graphical printouts of all text sent there using the VGA 8x8 > BIOS font to print huge amounts of text on one sheet of paper > but at the expense that printing happens only every 3 lines, > as I had a 24 "pin" printer at that time ;-) Of course this > meant that only plain text could be printed to LPTn+1, and > that you had to be careful printing to LPT1 while the tool > was active because LPT1 was where the actual printer was. > >> 5) Somehow "send" those codepages to the printers' RAM. (I'm aware >> that unfortunately not all printers might provide such a feature.) > I know that the 24 "pin" printer had that feature. You could > overload few, many or all character shapes depending on how > much of the RAM in the printer you wanted to spend: The more > characters you overloaded, the shorter the built-in FIFO RAM > buffer for printing would go, in the said 3 possible steps. > >> (At least in my mind,) this particular step would require some >> software to somehow analyze the codepages encoded into the FreeDOS >> codepage libraries (CPX files) and send the necessary info to the >> printers' RAM. > That would be a relatively easy transform as far as I remember, > the font encoding for sending custom characters was relatively > straightforward. I think Nx8, Nx16 and Nx24 font sizes could be > loaded, with some 8 to 9 and 16 to 24 upscaling done by the ROM > software of the printer to work on 9 / 24 pin hardware modes. > > Also, N could be different for each character if you selected > sending a proportional spacing font. As DOS codepages are made > for VGA, which has fixed character sizes, you could only check > whether characters have extra empty space at the sides and then > condense that to say one empty pixel after each character, to > automatically calculate a proportional spacing. Of course this > has to be user-selectable if you implement it at all, otherwise > ASCII arts and text screenshots would break. Those only work in > fixed spacing fonts, obviously :-) > >> Such step would naturally not be necessary to deal with >> regular codepages, like 858 or 808... > You assume that printers have codepage 858 in hardware. The > set of implemented codepages varies wildly and 858 which is > 850 plus Euro sign will probably NOT be implemented in older > printers but then it is a good example how loading only ONE > character (Euro) in the printer RAM can efficiently implement > some codepage by starting from another codepage, e.g. 850 :-) > > Some printers would for example support ASCII, 437, 850 and > something Asian (Katakana?) or Russian, but not necessarily > anything which is equal to any particular DOS codepage. You > would probably want to have a look-up table to work around > some differences. On the other hand, switching DIP switches > to select a codepage cannot be done in software, and sending > an escape sequence to select a codepage has to be done only > once (until a reset code arrives) so you could make a tool > which works on the COMMAND LINE and lets the user send such > escape sequences, as opposed to a driver which would do it > in more fancy ways (e.g. uploading fonts to printer RAM or > doing mapping with a look-up table or printing text using > images etc). > > I hope this mail explains more than it is confusing :-) > > Eric > > > ------------------------------------------------------------------------------ > WhatsUp Gold - Download Free Network Management Software > The most intuitive, comprehensive, and cost-effective network > management toolset available today. Delivers lowest initial > acquisition cost and overall TCO of any competing solution. > http://p.sf.net/sfu/whatsupgold-sd > _______________________________________________ > Freedos-user mailing list > Freedos-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freedos-user ------------------------------------------------------------------------------ WhatsUp Gold - Download Free Network Management Software The most intuitive, comprehensive, and cost-effective network management toolset available today. Delivers lowest initial acquisition cost and overall TCO of any competing solution. http://p.sf.net/sfu/whatsupgold-sd _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
