Subject: Re: [stella] What is at $029c and $029d? From: emooney@xxxxxxxxxxxxxxxx (Erik Mooney) Date: Thu, 21 Jan 1999 15:55:04 GMT |
>Dan was nice enough to send me a partly commented copy of the disassembled >SC-BIOS. Currently I'm trying to find out what the rest of the code does, >but there is something I don't understand. In the SC-BIOS there are read >accesses to $029c and read and write accesses to $029d. $029c seems to >work similar to INTIM, but I have no idea what $029d is for. Are they >undocumented RIOT ports or would it be possible, that the SC maps some >of its ports there? Does anyone have an idea? Going by the way we understand the 2600's memory architecture, those addresses would seem to simply get you RAM locations $9c and $9d (but they'd take an extar cycle to address because they're not zero page.) The RIOT does not decode address lines 8 through 11. I think. :) -- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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