Re: PET 50Hz editor ROMS

From: William Levak <wlevak_at_SDF.ORG>
Date: Sun, 27 Apr 2014 15:00:01 +0000 (UTC)
Message-ID: <Pine.NEB.4.64.1404271459180.20840@faeroes.freeshell.org>
I can't read xls.  Can you print it to a text file?


On Sat, 26 Apr 2014, Rob Clarke wrote:

> Hi William,
>
> I collected all the CRTC values from known ROM's into a spreadsheet, you can 
> find it here.
>
> http://inchocks.co.uk/commodore/PET/PET_CRTC.xls
>
> The one in the first column is row 8 on the sheet, which also gives you a 
> 50hz display but as you say, with slightly adjusted geometry.
>
> Rob
>
> On 26/04/2014 07:13, William Levak wrote:
>> 
>> On zimmers.net under PET firmware there 3 separate images for the 901474-04 
>> 50Hz screen editor ROM. I have compared them and found only a few 
>> differences.  The affected region is listed below.  The three columns below 
>> are the three different ROMs in the same order they are listed on 
>> zimmers.net.
>> 
>> $E787 is the ROM checksum.
>> 
>> The other data almost looks like random garbage, but it has a pattern.  It 
>> took me a while to remember where I had seen that pattern.  They are the 
>> register values for the CRTC.
>> 
>> According to my CRTC notes, the last column is values for an external PAL 
>> monitor.  The middle column is values for a 50 Hz internal monitor.
>> I don't recognize the values in the first column.  They are almost like the 
>> 60 Hz internal monitor, but the vertical spacing is different.
>> 
>> 
>> E72A:  31  32  3F
>> E72B:  28  28  28
>> E72C:  29  28  32
>> E72D:  0F  08  08
>> E72E:  27  26  20
>> E72F:  00  02  10
>> E730:  19  19  19
>> E731:  20  20  1D
>> E732:  00  00  00
>> E733:  09  09  08
>> E734:  00  00  00
>> E735:  00  00  00
>> E736:  10  10  10
>> E737:  00  00  00
>> E738:  00  00  00
>> E739:  00  00  00
>> E73A:  00  00  00
>> E73B:  00  00  00
>> 
>> E73C:  31  32  3F
>> E73D:  28  28  28
>> E73E:  29  28  32
>> E73F:  0F  08  08
>> E740:  31  30  24
>> E741:  00  00  11
>> E742:  19  19  19
>> E743:  25  25  20
>> E744:  00  00  00
>> E745:  07  07  07
>> E746:  00  00  00
>> E747:  00  00  00
>> E748:  10  10  10
>> E749:  00  00  00
>> E74A:  00  00  00
>> E74B:  00  00  00
>> E74C:  00  00  00
>> E74D:  00  00  00
>> 
>> E787:  BF  CD  BF
>> 
>> 
>> 
>> wlevak@sdf.lonestar.org
>> SDF Public Access UNIX System - http://sdf.lonestar.org
>>
>>       Message was sent through the cbm-hackers mailing list
>
>
>      Message was sent through the cbm-hackers mailing list
>

wlevak@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org

       Message was sent through the cbm-hackers mailing list
Received on 2014-04-27 16:00:03

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