Original adlib card had these spots but the IRQ one was unpopulated entirely and address one hardwired to D ($388) so every game works this way. Proper replica will have this too and that is all there is to it.

Is it still possible to use the IRQ settings and leave the port address hard wired/ unpopulated?

Or would using a different IRQ never work if a header is there?

IRQ is not used at all by any software using Adlib, enabling it may even lead to compatibility issues from software receiving unexpected IRQs (if the OPL2 timers are used since those are only thing that can cause the IRQ pin to do something).

One of the port address jumpers needs to be populated or the card will not be accessible at all.

Thought the card is already hard wired ( if i look for pictures online, most people dont install headers there, just some solder blobs. So why you saying thats needs to be populate is beyond me)

I installed only an header block on the IRQ (on one card to test it out, can always remove it when its not needed at all.)

(yes i placed only one jumper) the second one was to hold it in place so i could solder it)

Hi! I think what shouldn't be forgotten is that AdLib inc. aimed the card at musicians, not video game enthusiasts.
It was called the "AdLib Music Synthesizer Card" for a reason.

Second, being the first (okay, second) of its kind, it does of course offer multiple configurations.
Let's remember, this was the initial model.
Edit: The 1987 and 1990 model are virtually the same, no real redesign was done.

The software supporting it was barely even there yet.
There was no final standardization at this point.

- It wasn't clear to AdLib inc. if application developers wanted to use IRQs or not (they were scarce in an PC/XT, anyway).
- It wasn't clear if the default address of 388h/389h wouldn't collide with other popular expansion cards of the future.

So the company did the only right thing here, make things user selectable. Let the IT industry decide.

Also, by having multiple i/o ports, multiple AdLib cards can be installed.
This might be useful for music software, to increase polyphony.

My PAS16 did have ID jumpers, a similar concept, so a couple of PAS16 can be installed in a single PC. 🙂

Robin4 wrote on 2023-09-18, 01:42:

Thought the card is already hard wired ( if i look for pictures online, most people dont install headers there, just some solder blobs. So why you saying thats needs to be populate is beyond me)

By populated I mean that D needs to connect, if the card already connects (it does not at front, I guess it does on the other side) then there isn't anything needing to be done.

Having an IRQ connected allows OPL2 timer to produce an IRQ at the chosen level, no game expects them so only use is for any possible new software. (YMF71x chipset actually allows OPL3 to produce IRQs in its config but by default this feature is not utilized)

no game expects them so only use is for any possible new software. (YMF71x chipset actually allows OPL3 to produce IRQs in its config but by default this feature is not utilized)

Thats a good one. so it wont work in games that IRQ setting? Thought it should work the same like a Soundblaster 1.5
Iam not going it to use with new software. Its only used for retro gaming.

Sound Blaster cards (and all clones I have seen, besides YMF71x) do not connect OPL2 IRQ at all nor give any kind of option to do so. The IRQ on those cards is for the SB side and sometimes MIDI side and used to know when a buffer has finished playing or otherwise new data is needed or some other kind of attention is wanted.

Then you leave the IRQ jumper unconnected or there will be weird issues to be expected in some games (whatever they may be).

I never soldered those headers or connected any address pads and my card works fine at default address? Did I miss something?

appiah4 wrote on 2023-09-19, 05:24:

I never soldered those headers or connected any address pads and my card works fine at default address? Did I miss something?

those headers are unused and should not populated or messed with
I can't believe this discussions drags so long , one look on the original AdLib board and it should be evident these headers are not used
the only reason they exist on the replica is for replica reasons: meaning to look like the original

appiah4 wrote on 2023-09-19, 05:24:

I never soldered those headers or connected any address pads and my card works fine at default address? Did I miss something?

I thought the same.

Robin4 wrote on 2023-09-19, 10:15:

appiah4 wrote on 2023-09-19, 05:24:

I never soldered those headers or connected any address pads and my card works fine at default address? Did I miss something?

I thought the same.

*sigh* 🙄
Back in the day it wasn't uncommon to have something hard-wired being cut by the user with a knife.
Normally, that default connection was a very thin trace, between the solder pads.

The jumper position for D was likely left intact, so users can reverse their action.
And to install jumper headers.

Similarly, many CB and amateur radio transceivers have diodes installed on the PCB
that can be cut to enable certain features that were disabled by the manufacturer to comply to national laws.

Going to remove it, if its only the IRQ for the OPL2 chip and not for the whole card.