Re: DMA successes with Verilog

From: André Fachat <afachat_at_gmx.de>
Date: Fri, 15 Jun 2018 10:09:37 +0200
Message-ID: <164027e1a00.27e0.b4d1f2b66006003a6acd9b1a7b71c3b1@gmx.de>
Am 15. Juni 2018 09:56:45 schrieb smf <smf@null.net>:

> On 15/06/2018 04:52, Jim Brain wrote:
>> If I am reading the datasheet correctly, it can supply 100mA of power
>> to the !NMI line to pull it high, so I assume this circuit just
>> overwhelms the NMOS driver to ground.  If I am correct, that does not
>> sound healthy to a CIA.
>
> It's obviously out of spec, but the question is whether the output FET
> will suffer damage. The spirit of commodore 8 bits is to ignore the
> assumed rules and do what works.
>
> The ESM button works & I've never seen a warning about it. Although I
> accept that pressing the button is a relatively rare event.

I guessif it's only to trigger an NMI on demand, you could time the 
override correctly and keep it as short as possible to try not to cause 
(too much) damage.

At least that's why I probably would have done for that IFF I would have 
decided to go out of spec...

André
Received on 2018-06-15 11:00:04

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