> I still wonder how it will scan a character, do you set the "X-Y" > voltages for the character and then perform a scan of the character, > or do you scan a series of characters slice by slice?
You can do it either way. For VDU service, the CRT would be scanned as a normal raster (normally using magnetic deflection, which is much easier when doing a fixed raster), and the monoscope beam would cut a slice through each character on the line as it went. So the monoscope beam would be jumping around like mad (no problem, as it's electrostatic deflection) to get the pieces of patterns it needed. For succeeding scan lines, the monoscope beam would repeat the same pattern down a notch, and keep doing so repeatedly until the CRT had finished painting that line of characters. Then for the next line, the monoscope would have a different crazy pattern and iterate down the various character boxes. Alternatively, you could scan the characters one at a time, and for each one, set the position on the CRT (to where you wanted the glyph) and on the monoscope (to the glyph you wanted), and then scan mini-rasters with both of them in synchrony. This was done for adding small amounts of text to (say) a radar display. Occasionally, it would be a combination approach, for drawing short sections of text on a radar display (aircraft altitude, for instance). Then the CRT would get a mini-raster encompassing a small group of characters, and the monoscope would jump around, grabbing slices of those characters. Then the CRT beam would go paint another mini-raster for the next aircraft, and so on. In short, the monoscope simply doesn't care. You can deflect its beam any old way, and it'll give you an output telling you whether the current beam position is over a cutout area or not, instant by instant. That's all it does. How you use this depends on the stencil in the monoscope and your own creativity. - John -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
