johnf@stew.ssl.berkeley.edu (John Flanagan) (02/23/90)
In article <3313@pikes.Colorado.EDU> bscott@pikes.Colorado.EDU (Ben M Scott) writes: >[...] >...I can't figure out >how it works on the 1084 without twiddling knobs! It actually seems to be >scanning at a different speed... >[...] >How can the 1084 scan PAL with a 60 hz power supply? Don't ask me, I'm no monitor jock. I guess the monitor is able to sync up with the PAL refresh rate by luck. It must fall within the tolerances. I don't think the power supply frequency is used for anything to do with the video syncing, though, since I've heard that it is not precise enough for that. >Another interesting note: ECSTest >reports the Agnus is still in NTSC mode. Of course, this was the same program >that spelled it "NTCS", so what do you want to believe? I've never tried ECSTest, but I've never heard any good things about it either. Now for a question to the net (or Commodore, if they read this message): Is there a right way to do this? I tried to redo this program last night without needing to jump to ROM code, as Udi had done, but ran into the problem he mentions about there being no RAM available after reset. What I had wanted to do was jump to some code in RAM after the reset. Does chip RAM get pulled off the bus somehow after 68000 reset? Also, the 68000 reset instruction seems to cause Agnus to reset itself. Changing Agnus's video mode is easy, but RESETting seems to cause Agnus to re-read J102 and reassert NTSC mode. Is there some other way to restart the system without actually using the 68000 reset instruction, or which would not cause Agnus to reset itself? I realize that there is no absolutely right, supported way to do this kind of thing (BEAMCON0 is not even defined in the standard headers), but I had hoped to do something moderately portable across different Kickstart versions. Of course if this is a Preferences option in 1.4 or something, then I guess the question is kind of moot. I realize that there is a hardware jumper which could be cut to make a PAL/NTSC switch, but then I'd have to power down to change video modes, which would lose the contents of my ram disks. >Another question: How did you fit a Frances into a 500? I thought the Lucas >required extreme enough measures... and is it really as buggy as I hear? If the latest issue of AmigoTimes ever does make it to the newsstands there is supposed to be a picture of my setup in it, so you can see for yourself :-). The answer is that I didn't -- I remounted everything in another case. As far as the bugginess goes: mileage varies, but most people seem to be able to get it working just fine. Takes some tweaking and patience, though. John Flanagan Space Sciences Laboratory johnf@ssl.berkeley.edu University of California (...!ucbvax!soc1.ssl!johnf) Berkeley, CA 94720 Manners Maketh Man. (415) 643-6308