Re: Apple //e's RGB Card To Apple IIgs' RGB Monitor

[Mark McDougall <markm@vl.com.au>]

Bryan Parkoff wrote:

>     I believe RGBI port from Apple //e's RGB card has 14MHz signal.  It 
> should work with any ROM chip as clock cycle signal.  How do you say that it 
> is out of rate?  I can't imagine that ROM chip might be too fast for 14MHz 
> to handle.

No, the problem is that most ROMs are too *SLOW*, not too fast!
A 14MHz clock has a 71ns period, which is already at the high end of
EPROM access times. When you factor in setup, hold and OE requirements,
it gets tricky at those speeds...

Regards,

-- 
Mark McDougall, Engineer
Virtual Logic Pty Ltd, <http://www.vl.com.au>
21-25 King St, Rockdale, 2216
Ph: +612-9599-3255 Fax: +612-9599-3266