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Tandy Sound Compatible PCB

In my board it's badically just a voltage input so the power output won't affect the board.
 
Someone tested with SN76489AN? the bill of material report SN76489AN... it's right? It's only a matter to use a speaker and not i.e. headphone? or need some resistance increased?

I've finally found some conclusive information regarding the 89N vs the 89AN:
http://www.datasheetarchive.com/dl/226421d11320baa6b078c9e9ff62d31118651d/O/SN76489N

So the A is indeed a different revision in this case, and its output circuitry is modified somewhat, the output can now only drive 10ma, instead of the 100ma for the non-'A'.
 
Someone tested with SN76489AN? the bill of material report SN76489AN... it's right? It's only a matter to use a speaker and not i.e. headphone? or need some resistance increased?

This particular PCB comes with its own op-amp (LM386N). So it doesn't rely on the SN76489AN to drive the output. The LM386N should be powerful enough to drive headphones or small speakers (it can also be used with the internal PC speaker).
 
Correct, with 1W output it should be loud enough for pretty much all desktop use cases (approx 90dB with some basic HiFi speakers).
 
Correct, with 1W output it should be loud enough for pretty much all desktop use cases (approx 90dB with some basic HiFi speakers).

Heh, that's not what they thought at Creative at the time I guess. They used to put these 4W amps on their Sound Blasters. They had a stupid amount of power :)
 
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I wanna thank Great Hierophant and specially James for believing in this project. When i launched the thread in VOGONS forums almost 2 years ago, there had been a some talk but no real effort to push this forward, so i'm very happy that this project is in its last stages.

Ordered some PCB's and parts today, my Turbo XT will be the main test bed for the card in the C0h setting and i will also test the card in my socket 7 in the 1E0h setting.

Some games do allow forcing Tandy sound via command line interface, so i'm hoping the card works in my XT with a few selection of games i have in mind.

There is no doubt that some games need to be patched, and i think the 2C0h option is a very good idea. Maybe a tool can be written to redirect the writes to that port, which will allow a lot of games to work in 386+ systems.

Can't wait to test it!!
 
Got my PCB's!!! Now just waiting for the damn PSG chips arrive from Hong Kong. Super excited for this, can't believe it's been almost 2 years.

Thank you James!!

IMG_20161206_185741985.jpg
 
Got my PCB's!!! Now just waiting for the damn PSG chips arrive from Hong Kong.

Ooh nice!
My PCB is still underway, somewhere... Got a bunch of PSG chips coming in from Hong Kong as well, eta was somewhere between 6 and 18 Dec, so can be any day now :)
 
Well, don't get too excited yet... Brian has been working on the board for some time and it's currently preventing his system from booting :(
 
I own a T1000RL/HD and I love it, but it would be very nice to add the "tandy-sound" to my schneider tower at 286/10.
I read about the possibility to use a dac and a special software that "emulates" the tandy-dac, but this card should be the better choice.
But "F-16 Falcon" will then drop back to 4color-cga with the Tandy-Sound...but who cares, nobody has this version :)
 
Well that's a disappointment. So there will be further errata for the rev 1 board...
 
We need an OR gate (74LS32) to OR the '688 generated chip select with ISA IOW, and feed that to the sound chip /CS (pin 6).
 
Oh why did i order 2 PCB's... :D Anyway when you publish an errata i'll see if i can ghetto mod the additional IC with some wires
 
I'll supply replacement PCBs for just the post cost once the issues are sorted. In the mean time any testing would be great.
 
Of course, as soon as i can i'll build one board and test it on my XT. Which reminds me... What kind of system(s) has the board been tested already? XT's? AT's?
 
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