I have it, this evening ill try it.

Good to hear they are arrived!

Yobi, did you ship mine?
Thanks for that dream coming true!

What's you name?

Carles Bernardez

It sounds awesome!!!!!


VBR 128-160-190-320

SymAmp already makes some music But there are a lot of plops, and it seems, that it skips parts. I guess I currently have problems with the ATMega buffer synchronisation. Hope I can fix it later tonight. As I don't use the interrupt methode, I have to test one Bit of the status register, maybe here is something wrong.
Regarding the CPU usage, it seems, that we really keep about 25% for 128kbit MP3s, that's very nice!

Carles, i did send it last Monday.


Prodatron, for ATMega details you can contact Dennis.

Thanks Yobi

The default bufferlevel is set to 2, try 8 or so if you are sending small packages by entering:

OUT &H23,&H40
OUT &H22,&H08
OUT &H22,&H00
OUT &H23,&HC1

@DD: Thanx for the hint, that should be the same how I already do it.

This is my current code for initialising the MP3 decoder.
As I always want to send 2KB data blocks to the decoder, I set the buffer warning level to 1536 (=6*256).
Do you see some bugs here?

m3mreg  ds 4

;### M3MINI -> Initialise the MP3 hardware
;### Output     CF=0 ok, CF=1 error, hardware not detected
m3mres  xor a
        out (#22),a     ;reset mp3 decoder
        ld b,a
m3mres1 djnz m3mres1
        ld a,#00        ;read MP3 register 0+1
        out (#23),a
        call m3mwai
        ld hl,m3mreg
        ld bc,#422
        push bc
        push hl
        inir
        pop hl
        res 6,(hl)      ;no interrupts
        ld a,(m3mreg+2)
        and #f0
        or 6            ;warn, if buffer is lower than 1536 bytes (= 3.5KB - 2KB)
        ld (m3mreg+2),a
        ld a,#40        ;write MP3 register 0+1
        out (#23),a
        pop bc
        call m3mwai
        otir            ;write to ATM
        ld a,#c0
        out (#23),a     ;write to MP3 encoder
        call m3mwai
        ld a,#00        ;go to audio mode
        out (#23),a
        or a            ;**currently no detection implemented**
        ret

m3mwai  in a,(#23)
        and 16
        jr nz,m3mwai
        ret

Btw, I wonder, why you do OUT &H23,&HC1
Shouldn't it be #c0? (as you want to write back register 0)

When writing &HC1, you only update MP3 register 1. With the 4 OUT's in my previous post register 0 is not written.

I don't see any problems in your init routine, but try to give it more time to initialize after OUT &H22,0. In PLAYINFO you can see that OUT &H22,0 is given in the basic program, after this OUT the AtMega begins to upload the spectrum program to the VS1011, this takes time. To see if this really is the the problem you can give the OUT &H22,0 in basic or the assembler and execute your progam.

For these MP3 related functions (OUT &H22 and &H23) you can simulate a (hard)reset with OUT &H21,0.

Another way to check the buffer warning level is to read it back:

OUT &H23,&H01
? INP(&H22) 'Should be the number you entered
? INP(&H22)

Any news, Prodatron?

Enjoy this video http://www.youtube.com/watch?v=bkp4eSZLsJg