[Coco] Radio Shack's Audio Spectrum Analyzer for the CoCo 3

[Robert Gault]

Curtis,

I've been playing with a disassembly of the disk version of the Analyzer program and have added a
  LDA #%1010
  STA $FF9C
just before the program does a
  STA $FFC0  set up S-12
  STA $FFC2
  STA $FFC5
Now with S-24 and the $FF9C poke on a Coco3 you get S-24 without any text letters but it does not 
help the Analyzer program to get S-12 or S-8 mode.
Strangely enough the SN74LS783 specs indicate that while S-8 and S-24 can produce letters as well as 
block graphics, S-12 should just produce block graphics so maybe the disk version of Analyzer is 
incorrect.

Whatever, there are two places in the program where $FFC0-$FFC5 gets changed and I've tried lots of 
combinations with and without the $FF9C change. Nothing gives the desired result on a Coco3.
In S-24 mode there is no text and the screen is half the required vertical size. In what I assume is 
S-4 mode with many changes to the program to reduce the screen size on the vertical axis, there is 
not enough vertical space for the needed details.

I'd be happy to send you my disassembly and my initial mods to play with if you want. Maybe you can 
get Steve's program to work on a Coco3.

Robert

L. Curtis Boyle wrote:
> Robert, are you sure? I could have sworn that I have “fixed” both SG-12 and SG-24 graphics using that poke (with a different LPR value bit mask for each, of course).
>
> L. Curtis Boyle
> curtisboyle at sasktel.net
>
> TRS-80 Color Computer Games website
> http://www.lcurtisboyle.com/nitros9/coco_game_list.html
>
>
>
>> On Jan 10, 2019, at 9:13 AM, Robert Gault <robert.gault at att.net> wrote:
>>
>> A quick look at the Analyzer code seems to indicate that it uses the Semigraphics-12 screen format which is not available on a Coco3.
>>
>> Strangely enough the program at least looks correct with the VCC 1.02b emulator. The program almost looks correct with the MESS 1.34 version.
>>
>> Unfortunately you can't get a Coco3 to display S-12 graphics as you can S-24 graphics with a POKE to $FF9C.
>>
>> Robert
>>
>> Allen Huffman wrote:
>>>> On Jan 9, 2019, at 12:38 PM, Kevin Becker <kevin at kevinbecker.org> wrote:
>>>>
>>>> Did they ever make a CoCo 3 version?  As far as I know it only works on the CoCo 1/2.
>>>
>>> A CoCo 3 update was done, but was never released. I expect the code was lost with a bunch of other stuff that got stolen years ago.
>>>
>>
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>
>