Re: ROM Dump of Amiga Keyboard controller

From: Kajtár Zsolt <>
Date: Sun, 06 Jul 2014 17:51:36 +0100
Message-ID: <>
Hash: SHA1

>> I've made sources for both versions for easy comparison what was
>> changed: 
> The font layout in the old listing seemed better to me, as it showed how
> the numbers were calculated.
>> There were some IEC bugs (timing and responding to channels >=8), pen
>> didn't move far enough on change request and the steppers were not that
>> fast as expected. Rest seems to be optimizations.
> I did a diff, but more context would be of interest.
> Also, it looks like line 968  (#65) and 990 (#35) are constants that can
> be put at the top of the file, as are 889/903 time delay amounts (in the
> -03 ROM).

I've replaced magic numbers with constants and calculations now.

> line 835/837 is interesting.  Wonder what is going on there.

In theory it tries to avoid drawing outside of the canvas by lifting up the pen.

> lin 427 says unused, but the same line is in the -01 ROM.  Is it unused
> in both?

It's not used in -03, as the same function is done elsewhere. They've left
it in by mistake.

> Was the lack of storing cmd_x to >512 just an optimization?  How do they
> know it is 0 already?

It's an optimization. It does not have to be exact, just big enough to move
the head to the change position.

> Line 283 (#67) looks like another constant.

There are plenty of constants now for adjusting various things.

The normal asm/dasm files are on the place as before. But not for too long
as the temp directory is cleaned up periodically... Any chance to get this
to zimmers ftp?

- -- 
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