★ APPLICATIONS ★ DIVERS ★ SCREEN DUMP (YOUR COMPUTER) ★ |
| Screen Dump (Your Computer) | Applications Divers |
Eyemouth, Berwickshire Since I obtained a Brother M-10009 printer I have, of course, been plugging-in various routines to try and fully utilise its capabilities. However, because for some reason beyond my comprehension the Amstrad CPC-464 does not send bit 7 to the printer, some 50 per cent of the excellent printer characters are unavailable to me. In fact, I can't even get the printer's £-sign! I therefore quickly became interested in the idea of a screen-dump, and have been plugging in every such program that I have been able to find. However, I was unable to find one that satisfied my needs, so I decided to knuckle down and write my own. This screen dump is different from most in that it is designed for A4 size paper, somewhat wider than usual. Also, rather that dumping the whole screen, it dumps one line only, which is selected by sending a parameter — the line-number — to the machine-code. The whole screen can therebye be dumped from Basic, if required, or any line or set of lines that you may happen to require. The parameter can be either a constant or a variable. In order to make up the additional width, I have arranged for the four horizontal bits that must be interpreted from the display to be translated into six bits to be set to the printer. In order to retain squareness, I matched this vertically, so that each printed character is in fact twelve bits high rather than the usual eight. This has resulted in a "chunky" look which I find rather nice. Line-drawings, such as circles and squares, are therefore true in shape. The Basic Loader enables the machine code to be placed anywhere in Ram above Hi men — space is reserved if necessary. The complete code and variables occupies 253 bytes. Provision is also made for printers with a minimum line-feed unit of 1/36", instead of the 1/72" that is available to me — in fact, the M-10009 has a minimum line-feed capability of 1/216", but I do not use that in this routine. Because the printer has to make two passes for each line of print, the net printing speed is reduced accordingly, but this is more than compensated for by the additional graphics capability. In fact, anything that can be displayed on the screen can be copied to the printer. Note, however, that the graphics origin must be 0,0 before the machine code is called. The machine code does not assume ink 0 to be the paper ink, but tests to see what ink the paper is set to. That is the only colour not printed — all other inks are dumped.
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