On zimmers.net under PET firmware there 3 separate images for the 901474-04 50Hz screen editor ROM. I have compared them and found only a few differences. The affected region is listed below. The three columns below are the three different ROMs in the same order they are listed on zimmers.net. $E787 is the ROM checksum. The other data almost looks like random garbage, but it has a pattern. It took me a while to remember where I had seen that pattern. They are the register values for the CRTC. According to my CRTC notes, the last column is values for an external PAL monitor. The middle column is values for a 50 Hz internal monitor. I don't recognize the values in the first column. They are almost like the 60 Hz internal monitor, but the vertical spacing is different. E72A: 31 32 3F E72B: 28 28 28 E72C: 29 28 32 E72D: 0F 08 08 E72E: 27 26 20 E72F: 00 02 10 E730: 19 19 19 E731: 20 20 1D E732: 00 00 00 E733: 09 09 08 E734: 00 00 00 E735: 00 00 00 E736: 10 10 10 E737: 00 00 00 E738: 00 00 00 E739: 00 00 00 E73A: 00 00 00 E73B: 00 00 00 E73C: 31 32 3F E73D: 28 28 28 E73E: 29 28 32 E73F: 0F 08 08 E740: 31 30 24 E741: 00 00 11 E742: 19 19 19 E743: 25 25 20 E744: 00 00 00 E745: 07 07 07 E746: 00 00 00 E747: 00 00 00 E748: 10 10 10 E749: 00 00 00 E74A: 00 00 00 E74B: 00 00 00 E74C: 00 00 00 E74D: 00 00 00 E787: BF CD BF wlevak@sdf.lonestar.org SDF Public Access UNIX System - http://sdf.lonestar.org Message was sent through the cbm-hackers mailing listReceived on 2014-04-26 06:00:02
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