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Message from discussion RFC: ULA Replacement for ZX Spectrum SE
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Matthew Westcott  
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 More options May 16 2000, 3:00 am
Newsgroups: comp.sys.sinclair
From: gas...@raww.org.RemoveThisBit.invalid (Matthew Westcott)
Date: 2000/05/16
Subject: Re: RFC: ULA Replacement for ZX Spectrum SE
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On 16 May 2000, Günter Woigk) wrote this message in comp.sys.sinclair. Which
was nice.

>i suggest to use only one master address in the lower address byte with
>fully decoded 8 bits for all screen related outputs and use the high
>byte of the address as sub address to select the function and the data
>byte to transfer data (hey, seems to be intended that way by the zilog
>engineers :-)

It still means hogging 256 addresses though - I propose a similar system to the
AY chip, namely to have one port to select a 'register' number and one port to
determine the value of that register.

I don't really agree with the idea of multiple screen modes - I think the aim
should be to give the Speccy a few bells and whistles, not to design something
that amounts to a whole new computer system. We've got the Sam Coupe for that
:-)

--
Matthew Westcott
http://www.demo.eu.org/ - the home of the Spectrum demo scene
-------------------------------------------------------------
| "Standing in my yard, where they tore down the garage     |
| to make room for the torn down garage"                    |


 
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