Project has reached the modeling stage:

Very nice.
How does the filter curve with the different capacitor rating compares to a SID in C64?
Why did you chose a R4?

elianda wrote:

How does the filter curve with the different capacitor rating compares to a SID in C64?

I'm not sure I get your idea. What filter curve? Is it frequency response? Anyway, I have no C64 to compare.

elianda wrote:

Why did you chose a R4?

I know nothing about 6581s. Thus, to avoid any probable mess, I picked up the very same revision found on two SSI-2001 species I have seen. But the replica is using a cradle so that one can push any 6581 revision into it and see what comes out.

The prototype finally started working, thanks to our project engineer Fagear.

Here's the video: prototype test in Airball, Bad Blood and Ultima VI

It's voiceover is in Russian, turn on English subtitles. Actual game tests begin at 03:00.

Absolutely awesome project... Is there a plan to manufacture the pcb's in numbers? I guess a few people here will be interested in acquiring a clone.

Of course there is, I mentioned that earlier in the thread. After we tweak few things with our prototype, I will proclaim the estimated cost and gather the preorders.

Hello everyone.

I've found a technician who agreed to draw card scheme

And this technician is me. 😀

We've got some more progress: I received factory PCBs for first batch.
Now replica looks like this:

Card works fine but I'm having trouble with trying to run 8580 in it.
I've already added 78L09 into design for this chip, but there is no sound output from 8580. It clicks when card initializes (same as 6581) but nothing else.

Is there any difference in initialization mechanism between 6581 and 8580?

oh! just saw this reply here after seeing the yt video and PM'ing Fagear 😵
is it possible to get a pcb to build this?

Wow these are exellent quality PCB i ever have seen! WOW these are really looking nice...

I guess there is no Russian equivalent for the word "facepalm"? 😜

Cool card, I'm assuming Ultima VI's SSI soundtrack is identical to the C64 version.

NJRoadfan wrote:

I guess there is no Russian equivalent for the word "facepalm"? 😜

Cool card, I'm assuming Ultima VI's SSI soundtrack is identical to the C64 version.

Ditto about the board, but doubly incorrect about Ultima VI for the C64. First, the C64 version has just one tune, which drones on endlessly. Second, the SID in the Innovation runs at a slower frequency than either the NTSC or PAL C64.

NJRoadfan wrote:

I guess there is no Russian equivalent for the word "facepalm"? 😜

Well, there is, actually. Why?

NJRoadfan wrote:

Cool card, I'm assuming Ultima VI's SSI soundtrack is identical to the C64 version.

Great Hierophant wrote:

First, the C64 version has just one tune, which drones on endlessly. Second, the SID in the Innovation runs at a slower frequency than either the NTSC or PAL C64.

Well, replica has frequency jumper for this purpose: you can choose 0.89 MHz (SSI-2001) or 1.02 MHz (C64 NTSC).

There was the video from SSI-2001 owner. You can compare it to my videos: replica @ 0.89 MHz and replica @ 1.02 MHz.

Fagear wrote:

Well, replica has frequency jumper for this purpose: you can choose 0.89 MHz (SSI-2001) or 1.02 MHz (C64 NTSC).

That exactly was Great Hierophant's idea in the first place.

Isn't that potentiometer a bit too close to the cap ?
Also, this looks really good. The V2.1 PCB is god like in quality.

Can this card be used for SID music playback in a PC? (Once, and if, you manage to work the 8580 in it)

Stojke wrote:

Can this card be used for SID music playback in a PC? (Once, and if, you manage to work the 8580 in it)

Not yet. However, I'll look forth to make a PC-compatible SID music player to work with SSI-2001. The card deserves more than just the howling sawtooth music that's squeezed out of it by existing games and MIDI drivers.

Yeah, i had that in mind when i asked, for somebody to make a cool program 😀

Also, wouldn't it be better if you add an socket for those two caps that need to be replaced in case a different SID Chip is used? As well for the transistor?

Incredible result there guys, really like how you added legends for the jumper configurations and filter caps - also the first time I see my name on a PCB 😀
Also nice to see that someone from russia once again decided to preserve this piece of hardware, doing so seems very popular in the russian speccy scene.

Any chance to still hop on board and/or get the CAD/Gerber files required?

shock__ wrote:

Incredible result there guys

Thanks, but we do not have final result yet.
There at least two problems:
1) replica doesn't work correctly on fast PCs
2) 8580 doesn't sound at all
😐

I don't know if anyone outside Russia can download files below (because of cyrillic file names), but I'll provide them anyway.
Example of MIDI playback on replica (with 6581) on 386DX40 PC. Everything works just fine.
Example of same MIDI on faster PCs (468DX-66 + 4DPS, P-233MMX + Asus TX97-E, K6-2-500 + LS 5MVP3). Melody can hardly be guessed.
Example of same MIDI "playback" on replica with 8580 installed. No music, only clicks synchronous with it. I've edited it and that's what I got. Feels like SID is doing something, but its output stages are switched off or disconnected from generator unit inside.

Possible causes for problem #1:
- some logic ICs were damaged in process of re-assembling replica;
- russian analogs (555 series) are not fully compatible with native 74LS(HS) series;
- something in restored schematics is wrong.
It can't be just original design fault, because there was video from the owner of the original card and it was running fine on Pentium.

Possible causes for problem #2:
- some logic ICs were damaged in process of re-assembling replica (same as #1);
- russian analogs (555 series) are not fully compatible with native 74LS(HS) series (same as #1);
- 8580 was damaged in process of shipping.

So now I'm waiting for some more ICs to arrive (components to build two more testing cards and original 74LS-series to compare with 555-series). When I'll get them I should find what's the cause of the problems.

shock__ wrote:

Any chance to still hop on board and/or get the CAD/Gerber files required?

Possibly yes, but even I do not have fully working one yet. 😀

P.S.
Some photos of half-assembled testing cards with 6581 and 8580:

One thing I might recommend is to use a dedicated oscillator (or two) instead of relying on the oscillator signals from the ISA bus. From what I could find out while collecting info for another project (custom pc104 card with 4-8x RS232 & 1x I2C interfaces) the OSC signal can be quite a bit worse on newer systems with ISA slots compared to older 8088/286/386 systems, not to mention it has a pretty wide range of 'valid' frequencies.

The CLK signal from the ISA bus might also be useable, tends to be cleaner and has tighter specs, but can still vary a great deal. Hence, dedicated oscillator on the card itself would be the best option.