BeebOPL choons

[JudgeBeeb]

I am at a complete loss. I have downloaded the exact same file from GitHub. The file size is 160K. When I load it into BeebEm I get this:

Anyway, I have uploaded an archive of all the SSDs (both regular and High Page) and another of all the music files that are presently on GitHub.

[richardtoohey]

Not sure if it helps anyone/it is probably a bit pointless now, but if I go to https://github.com/lazarusr/BeebOPL/blo ... roplay.ssd it shows on-screen as 155 KB.

Download it and:

Code: Select all

$ ls -l Downloads/droplay.ssd                                                  
-rw-r--r--  1 xxx  yyy  158976 Feb  4 15:09 Downloads/droplay.ssd
$ head Downloads/droplay.ssd                                                   
DROPLAY$CAMPELL$PINK   $FAIRY  $BRAZIL $(

Open that in Beebem, I get the correct display.

So looks OK on github.

[PitfallJones]

Hi,
I discovered you can also play all these great tunes on the PC with a WinAmp plugin available here:
http://www.adlibtracker.net/downloads.php
PJ

[JudgeBeeb]

Hi,
I discovered you can also play all these great tunes on the PC with a WinAmp plugin available here:
http://www.adlibtracker.net/downloads.php
PJ

You can do that; but that would be cheating.

On most modern PCs you would be using OPL emulation. On BeebOPL, you are using genuine '80s hardware.

[SarahWalker]

More than two months since my last release! To make up for it :

Here's Zone 66. Another Epic release from 1993, this democoder-authored game uses the CDFM engine, to combine 9 voices of OPL with 4 voices of samples. This is a bit of a stretch for the Beeb, so there are three versions here.

The standard version will work on a 32k machine, but uses the Adlib soundtrack, which has no samples. And is therefore boring.

The Master 128 version requires sideways RAM banks 4-7 to be available for sample storage. This version mixes samples at 7.2 kHz and plays back through the internal Beeb sound chip, which is a pretty poor sample playback device and hence sounds pretty grainy. It also has to use ADFS to fit everything on a disc - it just about fits on a 640kb L-format disc.

The Master 128 + DAC outputs through an 8-bit DAC connected to the printer port. This sounds much better, partly due to an increased sample resolution, partly due to an upping of the sample rate to 9.8 kHz; still below the original's 22 kHz though. The downside is that I think I'm the only person to have this setup...

Anyway, enjoy!

[roland]

The Master 128 + DAC outputs through an 8-bit DAC connected to the printer port. This sounds much better, partly due to an increased sample resolution, partly due to an upping of the sample rate to 9.8 kHz; still below the original's 22 kHz though. The downside is that I think I'm the only person to have this setup...

Please share your setup with us, post a schematic diagram with this DAC.

[SarahWalker]

See attached crap diagram. R is 10k on my DAC.

[Arcadian]

Excite!!!!!

Will be setting my Master up tonight to try this as well as the new Bitshifters release (Bad Apple).

THANK YOU Sarah!!

[tricky]

Would that circuit be suitable to connect to the 1mhz bus?
Could it be connected to/through the beebOpl?

[JudgeBeeb]

Would that circuit be suitable to connect to the 1mhz bus?
Could it be connected to/through the beebOpl?

It is possible, but it would have to be somewhat more complex. If it were to sit on the 1MHz Bus, it would have to include address decoding circuitry. If one were going to go to the trouble to do that, one might as well throw in a full DAC IC as well. Sarah's solution of a resistor ladder on the User Port is much simpler and, importantly, is easily made on a bit of Veroboard for a few pennies. It probably wouldn't be that much more complicated to make some kind of audio mixer to combine the audio output of the DAC with that of the BeebOPL.

Whatever solution you use, you will also need to take into account the input impedance of the audio device being driven. In the (albeit unlikely) event that the impedance is low, this will have the effect of drawing more current than the Beeb can handle.

[tricky]

Sorry, I wasn't clear.
Sarah has her ladder attached to the parallel printer port and I was only thinking of connecting the output to the audio in on the 1mhz bus, not the ladder.
I was also wondering if the output could be merged with the beebOpl going in to the 1mhz bus audio in.

[JudgeBeeb]

Sorry, I wasn't clear.
Sarah has her ladder attached to the parallel printer port and I was only thinking of connecting the output to the audio in on the 1mhz bus, not the ladder.
I was also wondering if the output could be merged with the beebOpl going in to the 1mhz bus audio in.

I can't see any reason why not. In theory you just need to add in two resistors to appropriately attenuate the two signals. When Sarah was playing around with this at the last ABUG meeting, I seem to recall that the DAC output level was considerably quieter than that of the BeebOPL. So to match the signals, one would have to attenuate the latter output quite considerably.

[SarahWalker]

That was with the Beeb sound chip playing back samples. A real DAC should be a lot louder!

[Hedge]

Hi folks

Just thought some people might find this link of interest regarding ad lib sound card (and others!)

lots of interesting old vintage drivers too.

http://www.vogonsdrivers.com/getfile.php?fileid=129

rgds
Hedge

[daveejhitchins]

Just thought some people might find this link of interest regarding ad lib sound card (and others!)

Thanks . . . I'm sure it will be helpful

Dave H

[JudgeBeeb]

Time for another disc. Once again, this is one of the several music discs that AdLib sold to owners of the AdLib Music Synthesizer Card. This one was 'optimistically' called "Pop/Rock Grooves". All your 'favourites' are here including Traffix, Visions of Glory and Business Talk. Enjoy it (if you can).

P.S. I don't, at present, have a functioning BeebOPL card of my own. So I haven't been able to test it. Please let me know if there are any problems.

[Pernod]

I'm a bit late to the party discovering these choons, they're awesome

I wasn't into PC gaming in the 90's (was more into Amiga 1200) so not familiar with any of them but enjoying them all. Now to consider emulating the DAC to fully appreciate Zone 66!

[Pernod]

That was with the Beeb sound chip playing back samples. A real DAC should be a lot louder!

How loud should the DAC actually be? In my emulation it's almost drowning out the OPL, is there anything I can use for reference?