Re: 6502/6510 ROM selection daughterboard

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Mon, 04 Jun 2012 16:28:26 +0200 Message-ID: <4FCCC60A.2020005@laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 06/03/2012 11:35 PM, silverdr@wfmh.org.pl wrote:
>
>>> I am not sure that the CHAROM could be replaced in this way. I don't
>>> think it can be replaced with a 6510 daughterboard either, at least not
>>> without redirecting some PLA lines.
>>
>> No, any of these methods cannot replace character ROM.
>
>
> For CPU it should work, right? But for VIC it remains tricky. VIC lines
> come into picture /me thinks..

The Char-ROM is parallel to the other ROMs when it comes it address and 
data lines. The only special signal it needs is its _CS signal which is 
generated by the PLA. Since this is only one signal, the easiest way 
would be to grab it from the PLA pin 15.

Regenerating it from scratch needs a lot more signals.

  Gerrit

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