Manic Miner music keyboard error

[ceptimus]

I guess this has been discussed before, but I couldn't find it. I just noticed this as I'm currently coding a conversion of MM to the Colour Maximite.

 

On the Spectrum version, the piano keyboard on the title screen is wrong - the groups of black notes should alternate in twos and threes, but they don't - there are two adjacent groups of two black notes under the word 'ENTER'. I don't know if this error is also present in the Commodore 64 or other versions.

 

The code that highlights which notes are being played in Red and Cyan DOES have the locations of the black notes in the correct 2-3-2-3 sequence though - so all the black note locations on the right two-thirds of the screen are wrong.

 

The code works by flipping the attribute squares that contain the notes - but because the black notes straddle two attribute squares this wouldn't work properly for the black notes anyway.

 

As far as I can see, the black notes aren't used in the title tune.  I guess Matthew Smith was aware of the bug and just altered the music to avoid the black notes! Maybe that is part of the reason why the music is so annoyingly screechy!

Edited August 9, 2019 by ceptimus

[Norman Sword]

 

 

Halfway through typing this it posted, with an error message. Hence the retype on post #4

 

Edited August 9, 2019 by Norman Sword

[ceptimus]

Thanks.  I also realize now that I was wrong about the black note key mapping.  I was looking at Jim Bagley's code in his conversion of MM to the Parallax Propeller - which does attempt to map the black key positions (though wrongly).  The original Spectrum code only ever maps notes to the white keys.

 

Thanks for telling me that the played notes are different to the highlighted ones - I would probably have wasted hours trying to figure out why they were wrong.  Do you have any good references for what tones and durations the numbers in the tune table actually produce?

Edited August 9, 2019 by ceptimus

[Norman Sword]

1)

I guess this has been discussed before, but I couldn't find it. I just noticed this as I'm currently coding a conversion of MM to the Colour Maximite.

 

2)

On the Spectrum version, the piano keyboard on the title screen is wrong - the groups of black notes should alternate in twos and threes, but they don't - there are two adjacent groups of two black notes under the word 'ENTER'. I don't know if this error is also present in the Commodore 64 or other versions.

 

3)

The code that highlights which notes are being played in Red and Cyan DOES have the locations of the black notes in the correct 2-3-2-3 sequence though - so all the black note locations on the right two-thirds of the screen are wrong.

 

4)

The code works by flipping the attribute squares that contain the notes - but because the black notes straddle two attribute squares this wouldn't work properly for the black notes anyway.

 

5)

As far as I can see, the black notes aren't used in the title tune.  I guess Matthew Smith was aware of the bug and just altered the music to avoid the black notes! Maybe that is part of the reason why the music is so annoyingly screechy!

1) The topic is well known about and has been discussed by various forums.

 

2) The graphic layout of the piano keyboard although wrong has been copied onto various other machines. It is what Matthew drew, so even though it is wrong, it has been copied with the incorrect layout.

 

3) The locations of the notes being played and displayed on the graphic keyboard, have no relationship to the music playing. The offsets to each note that is played is based purely on its arithmetic value and this creates a linear offset to each note. The offsets should be logarithmic.

 

4) The note that is highlighted never encroaches onto the upper portion of the keyboard. The parts illuminated are all identical. 

 

5) The music played is a simple Pulse wave (square wave). Which because Matthew decided to use two waves generates a pulse wave difference. The sound you hear is the characteristic sound produced by the shifts in the values of each pulse. Similar to hearing Doppler shifts and harmony beats. The values used by the music have no bearing on how the music notes are seemingly played on the keyboard. So the values chosen were not influenced by the graphic depiction, With the consequence that no attempt was being made to avoid any part of the keyboard. The light up routine could play play a piano slide and thus light up each note in sequence if it was needed.

 

Edited August 10, 2019 by Norman Sword

[IRF]

In the post linked to below (and the files attached to that post), I experimented with the Manic Miner theme tune.

 

The 'pulse wave difference' which Norman refers to is caused by Mathew selecting pitch values for pairs of notes (the second and third byte in each group of three bytes which define the tune) that differ by a value of 1 (on the original game). Giving a disharmony quality to those notes that differ by 1.

 

In the attached experimental files (see link), I changed those notes so that they differed by a value of 2/4/8/16. The resultant 'magnitude of disharmony'* increases accordingly.

 

(*A good Manic Miner room name, perhaps?)

 

http://jswmm.co.uk/topic/458-free-space-and-code-optimisation-in-manic-miner/page-2?do=findComment&comment=10459

Edited September 16, 2019 by IRF

[IRF]

In the attached experimental files (see link), I changed those notes so that they suffered by a value of 2, or 4, etc

Obviously there was a typo there (in my previous post; now corrected).

 

Although the notes do sound as though they are suffering!