Re: ROM Dump of Amiga Keyboard controller

From: David Wood <jbevren_at_gmail.com>
Date: Wed, 2 Jul 2014 10:06:56 -0400
Message-ID: <CAAuJwiqiJBymZWYTjVAJHX3XK4ezte1Auf0C9XYd132tojdSbA@mail.gmail.com>
Considering the minimum clock rate, it's entirely possible to stall the
clock long enough to get from 0v to 10v on /reset before a clock cycle
completes.

By the way, these NOP loops are getting pretty long, would it make sense to
use a JMP at the end of the loop to avoid having the internal address bus
loop into onboard device or ram locations?

-David


On Wed, Jul 2, 2014 at 9:20 AM, Marko Mäkelä <msmakela@gmail.com> wrote:

> On Wed, Jul 02, 2014 at 02:07:37PM +0100, Kajtár Zsolt wrote:
>
>> The interrupt disable flag is set on any interrupts by default (including
>> reset). What's the reason to have SEI in there then?
>>
>
> Good point. Only if the internal firmware resets the flag with CLI or PLP
> very early, it could be needed. For example, if you first release RESET
> from 0V to 5V, and then to 10V.
>
> Anyway, I do not see why using 0x78 instead of 0xea for the padding bytes
> would cause any damage.
>
>         Marko
>
>
>       Message was sent through the cbm-hackers mailing list
>


       Message was sent through the cbm-hackers mailing list
Received on 2014-07-02 15:00:03

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