Re: ROMs replacement for narrow board

From: silverdr_at_wfmh.org.pl Date: Sat, 24 Nov 2012 23:10:15 +0100 Message-Id: <869AE06A-6233-40C5-8889-84B884CB3638@wfmh.org.pl>

On 2012-11-24, at 15:46, Gerrit Heitsch wrote:

> We really have to regenerate _KERNAL from  !(!A14 & !CS-ROM) which is
> 
> 
>                       |\
>         A14 ----------| \     |\
>               |\      |  )----| )O--  _KERNAL
>    _K/B ------| )O----| /     |/
>               |/      |/
> 
> Once we have that, the old circuit and ROM layout can be used again. Since you use a 74LS08, we have enough AND gates, the only thing missing is 2 Inverters:
> 
>                  +5V
>                  |
>                 | |  4.7K?
>                 | |
>                  |
>                  *----------------- out
>                  |
>  In    ___     |/
>   ----|___|----|
>                |\
>                  v
>                  |
>                  |
>                 ---
>                 GND

http://dl.dropbox.com/u/58002657/cbm/c64/rom_adapter_narrow2.png

Now, laying this out is going to be another challenge.. May force me to use SMDs as I guess I won't be able to keep the previous size with THDs.

-- 
SD!
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