MSX-EQ - PSG equalizer viewer

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Par Pyhesty

Expert (81)

Portrait de Pyhesty

27-03-2022, 16:46

Hello MSX! =)

now i'm release MSX-EQ - PSG equalizer viewer
in two version: "discrete" and "bars"

video:
demos with MSX-EQ
https://youtu.be/Vhv5bKJgaLk?t=324

games with MSX-EQ
https://youtu.be/E50GIDputWo

PCB version "discrete":

PCB version "bars":

If you have a music PSG demo that you would like to see with msx-eq, write here,
I will try to make a video with this demo =)

ps:
If someone is interested in the assembled board or the board in the cartridge, write pls to me by mail: pyhesty dog gmail point com (task: msx-eq and "discrete" or "bars" +- case). My friends and I will try to make a limited edition of them.

MSX 4ever!

!login ou Inscrivez-vous pour poster

Par ATroubleshooter

Expert (88)

Portrait de ATroubleshooter

27-03-2022, 18:51

Looks amazing! Keep it up, mate Smile

I would love to see Auf Wiedersehen Monty with this thing.

Par VWarlock

Supporter (12)

Portrait de VWarlock

28-03-2022, 10:31

Good jobs, man!
Cool stuff!

Par Wierzbowsky

Guardian (3527)

Portrait de Wierzbowsky

30-03-2022, 11:37

Looks cool! I want one in my collection!

Par sdsnatcher73

Prophet (3663)

Portrait de sdsnatcher73

30-03-2022, 15:25

Cool indeed, how are the nine bars related to the music being played? From watching the videos my eyes and ears can’t seem to make a lot of sense of it. Not sure if you get what I mean… (not sure if I understand Wink)

Par Pyhesty

Expert (81)

Portrait de Pyhesty

30-03-2022, 16:53

hello
thank you very much for your interest for msx-eq
Now I am working on a case made of translucent SBS plastic, I will definitely show the results pretty soon.
The case will be freely available as a stl model, on github.
As I become more free time, I will try to write in more detail about the board.

I try to answer all questions received by e-mail. I am very sorry that a mistake crept into the e-mail in the main post, a more accurate email address: pyhesty @ gmail com

Par Pyhesty

Expert (81)

Portrait de Pyhesty

30-03-2022, 15:36

sdsnatcher73 wrote:

Cool indeed, how are the nine bars related to the music being played? From watching the videos my eyes and ears can’t seem to make a lot of sense of it. Not sure if you get what I mean… (not sure if I understand Wink)

MSX-EQ board listens to the recording in ports A0 and A1 of the PSG. It analyzes the frequency and volume of a note and outputs it to the appropriate channel from the diodes. To enhance the visual effect, some additions were made to the signal processing. But the main dependence is the frequency and the volume of the note. Right now the higher frequencies are on the left (this matches the mathematical distribution of frequencies used, and I like it), maybe in the future I will change the order of the frequencies to a more natural one (low frequencies on the left, high frequencies on the right).

Par sdsnatcher73

Prophet (3663)

Portrait de sdsnatcher73

30-03-2022, 20:06

Okay, I think having lower frequencies on the left is more logical (it is how all audio equipment displays spectrum analysis). I think now a note played is shoppen on a single bar, maybe if you add a little value to the neighbouring bars (left and or right, maybe even a little as well to their neighbours) you will get a more even display. So say bar 3 is calculated to have value 6 (6 diodes on) then you could light up bar 2 and 4 with 4 diodes and and bar 1 and 5 with 2 diodes. If those bars also have notes playing they would override these values. Not sure how it will look in real life but in my mind it makes sense…

Par sdsnatcher73

Prophet (3663)

Portrait de sdsnatcher73

30-03-2022, 20:11

Also it seems the length a note plays is not taken into account, is that correct? Is it even possible to know?

Par Pyhesty

Expert (81)

Portrait de Pyhesty

02-04-2022, 11:08

Yes, you are right, the low frequencies on the left are more in line with the spectrum analyzer. I made a variant with the position of low frequencies on the left, and high frequencies on the right. As soon as I have free time, I will record a video and try to compare together. From the point of view of the visual effect, I was guided by the mathematical distribution of the use of the dynamic range of specified frequencies in the AY chip. And until I evened out this distribution, the visual effect was going mostly in one part. I preferred that the bars on the left would light up first. At the moment, the distribution is evened out and the bars on average light up in the central part.
I'll post a video later, sorry not now.
Below is an image of the typical mathematical distribution of codes transmitted in AY (inverse note frequency)

I do not plan to expand the image of one channel to two neighboring ones yet, but I will think about it. This is still a hardware limitation.
For me, developing that device is a hobby. At the beginning of the work, I limited myself to only the element base of the late 199s and early 2000s, and also use a minimum of elements. A little later I will tell you in more detail which PLD is used.
Thank you very much for your interest.

Par _ThEcRoW

Master (145)

Portrait de _ThEcRoW

16-04-2022, 15:17

Is this cartridge for sale?. I would be interested in one!

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