On 2/23/2018 5:11 PM, Mia Magnusson wrote: > Den Fri, 23 Feb 2018 22:52:06 +0000 skrev smf <smf@null.net>: >> On 23/02/2018 20:08, Michał Pleban wrote: >>> Sure, but the board for 6510 would have to be much more >>> complicated, and I am still not sure if tapping some signals from >>> the motherboard wouldn't be necessary. I am not sure if this would >>> be worth the effort. >> Probably not. How about >> http://westerndesigncenter.com/wdc/w65c816s-chip.cfm ? > I assume that everyone have had 65816 in their minds while discussing a > 6509 replacement. > > An interesting question though is how to handle that both 6509 and > 65816 provide more than 16 adress lines. Some kind of mux to select > 6509- or 65816-mode of addressing more than 64k? Seems like a quick job for a CPLD. The 65816 stows the bank on the data lines during the low clock period, as I recall. Just wire the data lines through the CPLD, and some of the address lines. Create a sequence of reads that the CPLD can watch to flip configs ($5555,$aaaa,$5555,$e000,$0001) to select which behavior you want, and use $0000 and $0001 as the 6509 have them. When in 6509 mode, ignore the DATA lines on low clock and replace with internal bank value. If 65816 mode, ignore banks and pass data lines through. Or, did I misunderstand the request? > -- Jim Brain brain@jbrain.com www.jbrain.com Message was sent through the cbm-hackers mailing listReceived on 2018-02-24 00:00:33
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