Subject: Re: [stella] 2600 Memory Map & Question From: Eckhard Stolberg <Eckhard_Stolberg@xxxxxxxxxxxxxxxxxxxxx> Date: Wed, 21 Jun 2000 19:31:47 +0200 |
At 00:25 21.06.2000 -0700, you wrote: ><EXTERNAL MEMORY> >Atari 2600 ROM Memory Map > >E000-FFFF 8K Rom >(shouldn't this be EFFF-FFFF? this is an 8K range above) Actually it should be $F000-$FFFF as those are 4kb. >1000-1FFF 4K Rom (mirror) >3000-3FFF 4K Rom (mirror) ></EXTERNAL MEMORY> > > >I am curious about something here. The 6507 has a 13-bit address >bus. This comes out to 8192 bytes linear addressable. Don't these hex >values jump around too much to fit within that address space? The 6507 has only 13 address bits on the outside, but on the inside it uses 16 bits just like any other 6502. Since the top three address bits don't have any pins to connect to on the outside of the 6507, you can specify every address in eith different ways. Ciao, Eckhard Stolberg -- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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