Re: Hardware emulation of 6509 using 6502?

On Wed, Nov 08, 2017 at 11:01:29PM +0000, smf wrote:
>On 08/11/2017 18:06, David Holz wrote:
>
>>On writing to 00/01, the 6510 enables a Write on the bus but doesn't 
>>assert the data pins. In the C64, the net effect is that the lingering 
>>prior data value from the VIC-II's bus phase will get written to those 
>>RAM locations.
>
>Does it have the same reliability issues to running code in de00/df00 
>from vic fetches, which vary by motherboard capacitance and 
>temperature.

I expect so. BTW, this question was asked here only a few weeks ago, and 
if I remember correctly, in reply to my reply, Groepaz posted a link to 
his test program that writes and reads the memory locations 0 and 1.

Also, on the C128 (not B128 aka 600/700 series) it is trivial to read 
and write these locations via the addresses $100 and $101 after 
redirecting the stack page with the MMU.

	Marko

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