On Wed, 30 Apr 2014, Clockmeister wrote: > > On 30/04/2014 11:06 PM, William Levak wrote: >> On Wed, 30 Apr 2014, William Levak wrote: >> >> The formula for the resolution is the resolution of the signal from the >> CRTC. 80 column machines double the horizontal resolution by logic on the >> system board. >> >> On examining the data closer, I see that there are both 40 and 80 column 50 >> Hz machines using the same CRTC data. The row in the table labeled >> "40 col. 50 Hz" should read "40/80 col. 50 Hz". These are probably the >> standard values. That leaves two ROMs using different values. One is >> clearly PAL. I don't recognize the other. It isn't NTSC. >> > > > SECAM? Original SECAM was 819 lines. The ROM requires 783 lines, probably close enough for SECAM. No other broadcast standard has enough vertical lines to handle it. According to Wikipedia, Paris and Monaco were the last ones to use this standard, ending in 1984 and 1985. Was there a BASIC 4 PET in 1984-1985 that required an external monitor? On the other hand, it is also close enough to Commodore's internal monitor that it would also probably work with it. The only way to tell for sure is to find someone with this ROM. If you have a 50 Hz PET with BASIC 4, PEEK(59178). If the result is 50, tell us what monitor you have. wlevak@sdf.lonestar.org SDF Public Access UNIX System - http://sdf.lonestar.org Message was sent through the cbm-hackers mailing listReceived on 2014-05-23 10:00:08
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