Re: Something else... 8501 GATE-IN

From: Gerrit Heitsch <gerrit_at_laosinh.s.bawue.de>
Date: Wed, 14 Mar 2018 19:58:14 +0100
Message-ID: <24b246a7-b3be-7ab9-f575-58d6e627ad75@laosinh.s.bawue.de>
On 03/14/2018 07:01 PM, smf wrote:
> On 14/03/2018 17:39, Gerrit Heitsch wrote:
> 
>> You can't leave AEC high all the time even if you run the RAM at 
>> double speed compared to now. The 8501 will not take its address lines 
>> offline, so when TED does an access, you will have to take AEC LOW to 
>> prevent bus drivers in CPU und TED fighting each other.
>>
> I was assuming you'd buffer them as part of the multiplexing and make 
> them think they were the only things connected to the RAM.
> 
> If you keep the CPU and TED clocked together then they will both start 
> their accesses at the same time, you'd then satisfy them both in the 
> same time the original dram would satisfy one.

That will produce problems with CPU access to TED registers.

  Gerrit
Received on 2018-03-14 22:36:51

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