| | tlr
Registered: Sep 2003
Posts: 1787 |
How do I reliably detect 6581/8580 sid?
There was an article in C=Hacking, but that does not work very well in VICE for example.
Maybe VICE's emulation is borked though.
I remember seeing a detailed analysis of the waveforms somewhere, but I can't seem to find it now.
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| | Frantic
Registered: Mar 2003
Posts: 1646 |
@MC: While it is nice to know how to check for various things, I get curious about what you will use this for? Will you make custom filter tables to make the tunes sound as similar as possible on different SID models and SID-emulation engines, or what? |
| | MC
Account closed
Registered: Jul 2009
Posts: 71 |
Exactly. |
| | iAN CooG
Registered: May 2002
Posts: 3187 |
ok, here's a new version =)
; Detect fastSID/reSID/reSID-fp/Hoxs/CCS/Frodo
; Just measure how much $d418 takes to decay from $1f to $00
; Experiment by iAN CooG, noticed first time in Excalibur intro exc-01
; Thanks to MC/Dutch USA-Team for checking CCS3 and real C64 timings
; Note: can't detect emulated sidmodel 6581/8580, values overlap.
; values | Engine
; ---------+--------
; xx xx 01 | hoxs (1cc00-)
; xx 07 00 | residfp (7ca-7df)
; bx 03 00 | resid (3bc-3cf)
; 8x 03 00 | ccs3 (38a-3a0)
; xx 01 00 | ccs2 (10f-11f)
; 7x 00 00 | real c64 (07d-08f)
; 0x 00 00 | fastsid (003-005)
; 01 00 00 | vice nosound (001)
; ff ff ff | frodo (never decays)
_id_hoxs = 0
_id_residfp = 1
_id_resid = 2
_id_ccs3 = 3
_id_ccs2 = 4
_id_realc64 = 5
_id_fastsid = 6
_id_nosound = 7
_id_frodo = 8
*=$0801
word eop
word 7102
byte $9e,"2059"
eop byte 0
lda #0
sta $0400
sta $0401
sta $0402
sei
lda #$1f
sta $d418
loop
inc $0400
bne nohi
inc $0401
bne nohi
inc $0402
lda $0402
cmp #$02
beq check ; or directly: beq frodo
nohi
lda $d418
bne loop
check
lda $0402
beq vice
cmp #$02
beq frodo
bne hoxs
vice
lda $0401
bne chkrs
lda $0400
cmp #$70
bcs realc64
cmp #$03
bcs fastsid
bcc nosound
chkrs
cmp #$04
bcs residfp
cmp #$03
bcc ccs2
rscc3
lda $0400
cmp #$b0
bcs resid
ccs3
ldx #_id_ccs3
byte $2c
ccs2
ldx #_id_ccs2
byte $2c
resid
ldx #_id_resid
byte $2c
residfp
ldx #_id_residfp
byte $2c
fastsid
ldx #_id_fastsid
byte $2c
nosound
ldx #_id_nosound
byte $2c
hoxs
ldx #_id_hoxs
byte $2c
frodo
ldx #_id_frodo
byte $2c
realc64
ldx #_id_realc64
lda offtablel,x
ldy #>stringtable
;cli ($ffd2 already clears int flag)
jmp $ab1e
stringtable
shoxs byte "HOXS64" ,0
sresidfp byte "RESID-FP",0
sresid byte "RESID" ,0
sccs3 byte "CCS 3" ,0
sccs2 byte "CCS 2" ,0
srealc64 byte "REAL C64",0
sfastsid byte "FASTSID" ,0
snosound byte "NO SOUND",0
sfrodo byte "FRODO" ,0
offtablel
byte <shoxs
byte <sresidfp
byte <sresid
byte <sccs3
byte <sccs2
byte <srealc64
byte <sfastsid
byte <snosound
byte <sfrodo
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| | assiduous
Account closed
Registered: Jun 2007
Posts: 343 |
using d418 fade out time to detect the sid model is abit risky. this thing has a very analogue nature so it depends on temperature and varies in a wide range. you will likely get different results on different chips and even on 1 chip when you test it cold and warmed up. some sids take so much time to drop bits from the write only registers that they fail the emufuxxor test.
i`ve run the program on an 8580,the first test shortly after the bootup printed C but 20 minutes later it changed its mind for good: screen shot
Sounddemon`s method can be trusted the most. |
| | MC
Account closed
Registered: Jul 2009
Posts: 71 |
Things come down to ranges of values of the low byte. In the current emulators I'm getting proper results, in CCS2 its hard to distinguish 8580 from 6581 emulation (but that's old crap anyway).
I'll up a testproggie and edit this post shortly.
Edit: http://tanx0r.org/mc/iantestprog.prg
Plz run that and tell me if the results are correct. TIA.
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| | MC
Account closed
Registered: Jul 2009
Posts: 71 |
Now that I come to think about it, I already have conclusive results when combining the results from D418 and D41B tests.
I know which SID emulation is running and I detected the SID model being emulated in all situations but vice/fastsid.
Knowing the situation in which a song was created will allow people to compensate. Also, an editor can have seperate settings for different SID models and even emulations. Knowledge == power. |
| | Frantic
Registered: Mar 2003
Posts: 1646 |
But... :)
Even within the category of "6581" sids there is a considerable variance in the filter characteristics, and I guess the same also the case when using resid-fp for example, depending on which 6581 variant (or 8580 variant) you choose and so forth? :)
Personally I eventually gave up on the filter issue around one or two years ago, hehe.. :) (Well, I do some minor adjustment depending on whether it is 8580 or 6581, but more than that... nah..)
Anyway, it is interesting to see what you come up with, so I am not trying to discourage anyone or so. Just providing my own take on the matter.
//FTC |
| | MC
Account closed
Registered: Jul 2009
Posts: 71 |
Well if we're gonna detect a SID let's just do the best possible job while at it... Afterall the question isn't a simple "why" but rather "why not"... |
| | MC
Account closed
Registered: Jul 2009
Posts: 71 |
Okay. More testing has been done and I added JAC64 to the list of recognized emulators. iAN is correct in stating you can't judge whether you're dealing with 6581 or 8580 emulation from the D418 timing test.
I have created wider margins on the recognized ranges as well so it should really always correctly detect SID + emulation now through combined D418 timing and D41B testing for high bit.
Note: EMU64 doesn't give any reliable results and is recognized as VICE/NOSOUND.
Here's the table:
; min max med hi sidcode
recogtab: dc.b $00,$00,$CC,$01,0 ; HOXS, 8580
dc.b $A0,$F0,$07,$00,1 ; VICE, RESIDFP
dc.b $B0,$E0,$03,$00,2 ; VICE, RESID
dc.b $70,$B0,$03,$00,3 ; CCS3.X
dc.b $01,$28,$01,$00,4 ; CCS2.X
dc.b $20,$FF,$00,$00,5 ; Real C64
dc.b $02,$0F,$00,$00,6 ; VICE, FASTSID
dc.b $00,$01,$00,$00,7 ; VICE, NOSOUND
dc.b $00,$00,$00,$02,8 ; FRODO
dc.b $C8,$E8,$01,$00,9 ; JAC64
Testproggie: http://tanx0r.org/mc/iantestprog2.prg
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| | Jak T Rip
Registered: Feb 2002
Posts: 39 |
Hi guys,
I tested the latest test program with my real C64 and
- the SID and VIC type are reliably detected (8580 PAL 50Hz)
- emu type is detected as
1) Unknown when I have no additional HW on (or with SCPU in 1Mhz mode)
2) Frodo in case I have a SuperCPU running in 20Mhz
The displayed values for normal unenhanced C64II are
xx:98:00
The first value is completely unreliable. I get values between 1x and fx.
The second value is very stable. I get values around 98, sometimes 99 or 9a, but never far off. |
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