Re: [hatari-devel] TT hardware memory information

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The TT has a sync mode register at the same address as the ST (0xff820a).  
However, it's not set up the same way.  TOS3 initialises it to 0x01 very early 
in initialisation, and it is not updated elsewhere.  While getting EmuTOS 
working on my TT, I discovered that, if this is set to 0x00 or 0x02 (like it 
would be on an ST), there is NO output to the screen: my LCD monitor remains 
blank, although it does detect the correct screen size and refresh rate.

In the "Atari TT030 Hardware Reference Manual", June 1990, there is a note that 
bit 0 of this register is 'set to 1'.  There is no further explanation.


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