Re: 264/TED/Plus4 Story

From: Gerrit Heitsch <gerrit_at_laosinh.s.bawue.de>
Date: Sun, 30 Oct 2011 18:18:51 +0100
Message-ID: <4EAD86FB.9010507@laosinh.s.bawue.de>
On 10/30/2011 12:46 AM, crock wrote:
>>
> Here's a selection of pics of the Commodore 232.
>
> http://inchocks.co.uk/c64/Commodore232/

Thank you for the pictures.

The whole system looks production ready to me, but the kernel ROM with a 
-01 rev is a bit old. It should run with a -05 just as well. Did you 
ever try that?

The interesting part about it is the RAM setup using 4 x 4416. Since TED 
only generates _RAS and _CAS for a single RAM bank this will have to be 
split up externally, probably using A13 to select the proper bank by 
somehow gating _CAS (_RAS needs to be on all RAMs to allow proper 
Refresh). The only difference in TTLs I can find compared to a Plus/4 or 
C16 are 2 TTLs, a 74LS74 (U17) and a 74LS32 (U13, datecode 7932?) which 
is not quite what I expected. The circuit I had in mind doesn't use a 
flipflop. Very odd...

  Gerrit


       Message was sent through the cbm-hackers mailing list
Received on 2011-10-30 18:00:18

Archive generated by hypermail 2.2.0.