• Please review our updated Terms and Rules here
  • From now on we will require that a prefix is set for any items in the sales area. We have created regions and locations for this. We also require that you select a delivery option before posting your listing. This will hopefully help us streamline the things that get listed for sales here and help local people better advertise their items, especially for local only sales. New sales rules are also coming, so stay tuned.

Wanted: AdLib Sound Card

per said:
Seems like you replied before my latest reply...

But, nope, AEN must be in there due to the nature of how the DMA controller works, but this wouldn't be a problem if we go for the solution I suggest.

I'd still love to see volume-knobs which you can alter without opening the chassis, though...
Click to expand...

This is why I'm glad I'm only working on a PCjr version, haha. No DMA in a PCjr! Instead of AEN, there's a signal called HLDA (Hold Acknowledge?), but I'm pretty sure I can ignore that.
 
jmetal88 said:
This is why I'm glad I'm only working on a PCjr version, haha. No DMA in a PCjr! Instead of AEN, there's a signal called HLDA (Hold Acknowledge?), but I'm pretty sure I can ignore that.
Click to expand...

HLDA is there to allow the CPU to acnowledge any waitstates you may be adding, and you don't really need to care about it unless you need to add waitstates. Doesn't the PCjr add a waitstate every instruction in the first place?
 
lynchaj said:
Thanks Per! Can we some how manipulate the 74LS688 with the flip flop or AND gate to squeeze out another address line of decoding? A1 is hanging loose so the YM3812 decodes to a pair of mirrored IO ports. I tried screwing around with the inverter and an AND gate and just made a mess of it. I was also thinking since this is an IO only decode can we *safely* ignore AEN (DMA active) and use A1 to activate the output of the 74LS688? Maybe I am over thinking this.

I settled on just accepting the 4 IO addresses but would love to see an innovative way to fix this without adding more chips. Actually if anyone has suggestions on how to *reduce* part count that would be even better.

Thanks and have a nice day!

Andrew Lynch
Click to expand...

Why don't you pipe A1 and AEN into one of these circuits, and tie the output to the 74ls688 enable?

dl_or2_sch.gif


Yeah, it adds three components, but diodes and resistors are really easy to come by.
 
per said:
HLDA is there to allow the CPU to acnowledge any waitstates you may be adding, and you don't really need to care about it unless you need to add waitstates. Doesn't the PCjr add a waitstate every instruction in the first place?
Click to expand...

It might, I'm not really sure. Seems like I remember reading something similar once.
 
Hi Per! I made some changes to include the new IO decoding logic with A1. Please check the 74LS74 flip flop if that is how you intended for using it as an inverter.

Also updated the labeling of the jumpers on the schematic and the PCB.

Haven't moved the volume potentiometers to the outer edge of the PCB yet though. I need to research some parts to find a right angle 10Kohm pot that will work.

There are new schematics, PCB layout, 3D rendering, and parts list at the N8VEM wiki. Please review and post comments, corrections, etc.

Thanks and have Happy New Year!

Andrew Lynch
 
lynchaj said:
Hi Per! I made some changes to include the new IO decoding logic with A1. Please check the 74LS74 flip flop if that is how you intended for using it as an inverter.
Click to expand...

That looks about like what I described, only difference being that I didn't think about the posibility of jumper A1 past the inverter.
 
Cloudschatze said:
Just curious, but why is adding support for the OPM/OPP chips at all desirable?
Click to expand...

Because many of us has some kind of old Soundblaster or other OPL2 card already, it makes the card more flexible, and the OPM/OPP is more advanced than the OPL2.
 
per said:
Because many of us has some kind of old Soundblaster or other OPL2 card already, it makes the card more flexible, and the OPM/OPP is more advanced than the OPL2.
Click to expand...

Right, but, as far as I am aware, there is no existing support for the OPM/OPP in that sort of configuration, so it's going to require specialized programming.
 
Cloudschatze said:
Right, but, as far as I am aware, there is no existing support for the OPM/OPP in that sort of configuration, so it's going to require specialized programming.
Click to expand...

Of course, but that's why it is optional. If anybody intend to use the card only for OPL2 support, all the required jumpers can be soldered with regular wire at practically no extra cost.

The I/O address select would also be of excess if the intention was AdLib-only support.
 
Hi! Happy New Year!

Seriously, the generic OPL2 board is completely distinct from the AdLib board. If it can be configured to be compatible that's great but it is a side effect.

I've seen pictures of the AdLib board and this board is very different. It is a sound board using the OPL2 with configuration options to support sound other chips.

We need to get away from anything AdLib related. That's copyrighted material and this is a public forum! One C&D letter from AdLib legal staff and this project is a goner. Just because it is ancient technology doesn't mean the IP owners (whoever they are) don't care about it. Please don't kill it by making it look (falsely) like it is an AdLib clone board! It isn't!

Please start a new thread and let's talk about making an OPL2 sound board.

What I think we need to discuss is who is going to be our initial build and test team? Any volunteers? We need prototype boards if anything is going to get done. Also we really need a project manager and a software lead. The hardware is mostly ready to go (except for the external volume pots) for an initial prototype.

Please let's start a new thread and get this organized. Thanks and have a nice day!

Andrew Lynch
 
There http://www.vintage-computer.com/vcf...71-8-BIT-OPL2-Sound-board&p=162874#post162874

Done.

Yea, I'll throw my hat into the ring to be a tester, but I'll need help in parts sourcing. If you could throw together a whole unassembled kit my way, I'll be glad for it, otherwise it'll take me a few months to get it all together. It took me several months to get around to finishing my xt-ide as it was.

As for the opl2, if they can be found, great, but if not, I do have 2 working soundblaster 2.0 that I could grab an opl2 off. I was considering on then adding a chip socket to the soundblaster, and to this kit, so that the opl2 chip can be easily removed and transferred. I'd probably add chip sockets to this kit for all the chips anyway for easy salvaging. But what about opl3 chips? They are backwards compatible arn't they, and much more plentiful.
 
lynchaj said:
We need to get away from anything AdLib related. That's copyrighted material and this is a public forum! One C&D letter from AdLib legal staff and this project is a goner. Just because it is ancient technology doesn't mean the IP owners (whoever they are) don't care about it. Please don't kill it by making it look (falsely) like it is an AdLib clone board! It isn't!
Click to expand...

A derivative work claiming "Ad Lib compatibility" isn't going to get anyone in trouble. Not to mention the fact that Ad Lib itself has been defunct for the past fifteen years.
 
Well, my idea turned out to be harder to implement than I thought. I put my Sound Blaster back together.

I think my efforts might be better spent making a sidecar-to-ISA adapter, and perhaps using the non-DMA functions of the Sound Blaster.
 
You must log in or register to reply here.
Back
Top