jsgn3@tnofel.fel.tno.nl (Jos Groot) (01/25/91)
I recently bought a Taxan Multivision 795 (multi-scanning) monitor. The specifications are very good, i.e., it can adjust itself to horizontal scan frequencies in the range of 30-57 kHz, and to vertical scan frequencies between 50 and 100 Hz. However, this is too good for my BBC model B (sniff !), that produces a vertical sync pulse with a frequency of 15.625 kHz. Now the video signal of the BBC is controlled by two IC's, the 6845 CRTC and the video ULA. I think it should be possible to alter the (timing) registers of these two IC's in such a way that the Taxan can be used with the BBC B. I tried this yesterday, and it looked promising (and, as a bonus, demonstrated that the Taxan can produce some musical whistles). My experience with the CRTC and ULA is too limited to figure it out in detail. So my questions are: 1. is it possible to use the Taxan with my BBC B, in all 8 screen modes ? 2. what are the values I have to put in the various registers of the CRTC and ULA to produce an image, for all screen modes ? Thanks in advance. -- Jos Groot Physics and Electronics Laboratory FEL-TNO P.O.box 96864 2509 JG the Hague