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Does the warm-up change the behaviour of anyone else's Dragon in the same way? I haven't had time to test your programs, but my D32 dislikes the double speed poke. It will run for a short while before crashing but I never timed it, nor did I work out if the crashing is time or temperature related. ...

Thanks!

Perhaps when someone with a little more (read: some) elec-eng knowledge gets back from holidaying you can get a real answer to that one

I look forward to that time. Do any of your D64's behave in the same way when running my BASIC test program?

Does the warm-up change the behaviour of anyone else's Dragon in the same way?

I guess so - for however long the RAM can go without refresh. Interesting thought though - you should definitely be alright for some short time into the vertical refresh - I think some experimentation is in order On my D32 the following BASIC program works perfectly for about 15 minutes. No crashes...

Graham Kinns' reckons here that it reduces interference with the colour subcarrier, but it also happens that the ratio is nearly spot on that of NTSC to PAL line rate - very very close, but not exactly the same. Possibly some televisions benefited from the line rate being closer to PAL spec? I'm ho...

According to the SAM data sheet, yes. Think of it in terms of the SAM having only two "slots" for RAM accesses - usually one goes to the CPU and one to the VDG. RAM refresh occurs during horizontal blanking when the VDG isn't using its slot. In fast mode, the CPU takes both slots, with no convenien...

Some questions... (1) Is it true that RAM refresh is disabled on Dragon/CoCo machines when running &HFFD9 mode? (2) Can anyone please explain exactly why Dragon Data fitted 14.218 MHz crystals in some Dragon 32/64s resulting in a slower clock speed? (3) Does anyone actually have a Dragon that will r...

Thanks Ciaran!

Merry Christmas to you and your family.

Thanks for sharing!