Raven. A homemade Atari-like computer

[agranlund]

Yes the first non dos/pc with a GUS😀
32 channel mod file!! Awesome sound quality.

Next adlib card 😀
Awe64 were will you stop…

I got really lucky and stumbled upon the old Interwave-DDK with example sourcecode equivalent to how iwinit.exe/ultrinit.exe puts the card into a sensible default state on PC's.

Without that I think it would have taken a lot of head scratching to realise all mixer connections starts off muted by default - and that the Synth is disconnected from it in favour of AUX1. It's all in the datasheet of course but in my defence that's quite a large document so having the DDK helped tremendously :)


I think an OPL3 card would be a perfect fit next to that GUS :)

[Oldskool]

So OPL2,3/GUS/YM/MIDI.

So besides playing music when porting stuff you always have the best sound option available.

[agranlund]

So OPL2,3/GUS/YM/MIDI.

So besides playing music when porting stuff you always have the best sound option available.

Yep would be nice to experiment with support in some interesting software. Doom/Quake could potentially preload sounds onto the card to play sfx for free without software mixer. Perhaps ScummVM could be made to use hardware OPL when available.

But most of all, it's just really fun messing about with all these choices of ISA cards.

Speaking of.. this nice thing appeared today:

opl3.jpg

I think this tiny card might be a pretty nice match with its internal audio output that I can connect to one of the GUS's headers for external inputs.

[mikro]

ScummVM not only could but already does support hardware OPL ;) (it's called RetroWave) I purchased the Express flavour for some tests with the RPi, worked very nicely.

Btw were there any ISA USB cards? Perhaps adapting a USB driver from FreeMiNT wouldn't be so much work then.

[agranlund]

ScummVM not only could but already does support hardware OPL ;) (it's called RetroWave) I purchased the Express flavour for some tests with the RPi, worked very nicely.

Ooohh, nice! :)

Btw were there any ISA USB cards? Perhaps adapting a USB driver from FreeMiNT wouldn't be so much work then.

I'm not really sure? LGR did a review of one but I'm still not quite sure if that was hardwired as a drive emulator only or if exposes a usb host chip directly.
I wonder if making a new ISA card with an ISP1160 would be the path of least resistance, to take advantage of existing Atari drivers?
May as well have an RTL8019 on the same card too and be like a Netusbee clone on isa.

The more I think about it the more it makes sense to have both of those chips on the motherboard fast bus for better throughput, but then decisions would have to be made on what to prioritise in terms of I/O connectors on the back.
Maybe it doesn't really need built-in midi since that is so readily available on isa cards? Would free up connector space, as well as freeing RX/TX on MFP2 for some other purpose (a serial->SPI chip maybe?)
It's easy to get overwhelmed by options.. just like when visiting the local pizzeria :lol:

Realistically though, Rev.A1 is going to be very similar to the one I have now with mainly must-fixes and some of the higher priority nice-to-haves I feel are missing. Just made presentable enough to be allowed outside the house and on Github.

[Oldskool]

Realistically though, Rev.A1 is going to be very similar to the one I have now with mainly must-fixes and some of the higher priority nice-to-haves I feel are missing. Just made presentable enough to be allowed outside the house and on Github.

I saw the G… word.
This is my “I don’t have BOM but I probably can use these parts which I have gathered today and put in this box for the Raven” picture. What is yours?

IMG_1760.jpeg

[nokturnal]

So OPL2,3/GUS/YM/MIDI.

So besides playing music when porting stuff you always have the best sound option available.

Yep would be nice to experiment with support in some interesting software. Doom/Quake could potentially preload sounds onto the card to play sfx for free without software mixer. Perhaps ScummVM could be made to use hardware OPL when available.

I still have SB driver in pipeline for my opl player. Got adapter for mega st(or ste?), but still I have to install it (not sure if it is 8 or 16 bit interface). And I thought about trying out GUS through vme or other isa adapter. I saw that Milan(or Hades?) had full SoundBlaster support(MilanBlaster), but it wasn't open source (which sucks) and it seems to be 'feature complete'. Maybe you could find some inspiration there for system integration (at least on interface/tools level). OPL part is easy.. If you could provide opl port write routs / detection I could make Raven Sound Blaster driver easily and incorporate it in my player/opl driver lib (,which is not public yet).
Scumm probably has opl drivers, Doom has integrated opl support, but it maps opl instruments to midi standard (,so it's basically midi events triggering opl tones/instruments, which are opl presets needed to be written into registers). Quake doesn't have midi, it has usual digital sfx and soundtrack (by NIN) streamed from cd.

[Oldskool]

I'm no expert but that OPL3 card is probably (for sure) adlib compatible as the OPL part of the SB is. So if the SB is non PNP (at least if the OPL part is) and jumpered to the same address the computer sees the same stuff so it should work I assume.
The other part of the SB needs DMA as far as I know. This is not strictly needed for the GUS.

But I have the feeling we will hear some OPL tunes in the near future............

[agranlund]

I still have SB driver in pipeline for my opl player. Got adapter for mega st(or ste?), but still I have to install it (not sure if it is 8 or 16 bit interface). And I thought about trying out GUS through vme or other isa adapter. I saw that Milan(or Hades?) had full SoundBlaster support(MilanBlaster), but it wasn't open source (which sucks) and it seems to be 'feature complete'. Maybe you could find some inspiration there for system integration (at least on interface/tools level). OPL part is easy.. If you could provide opl port write routs / detection I could make Raven Sound Blaster driver easily and incorporate it in my player/opl driver lib (,which is not public yet).

I think you need ISA-DMA for SoundBlaster to play PCM efficiently (or at all) ?
I'm under the impression those cards are a bit similar to how the Atari works in that you do all your sound processing on the CPU and have DMA set up to constantly feed a "dumb" DAC with your output mix.

Some SB document I found mentioned a limited direct PIO access to the DAC but I couldn't see any mention of FIFO so worst case that may end up being a bit like feeding a Covox through fast-firing interrupt?


I deliberately skipped the complexity of adding a DMA controller on the board because I couldn't think of anything other than SoundBlaster needing it for PCM playback.
This does paint it into a corner of needing a GUS or AWE32/64 for good audio and they are unfortunately more expensive.
But then again, you get *really* good audio and these cards do mostly everything for you and for free including mixing of up to 32 concurrent PCM channels.
Picogus does make it more affordable though and open source which is awesome.

Good advice looking at MilanBlaster!
I absolutely need to write some kind of similar accessory for controlling the volume of all the in/out ports of the soundcard.
A TOS4 sound xbios implementation would be nice to make too as a sort of worst-case fallback.

[agranlund]

If you could provide opl port write routs / detection I could make Raven Sound Blaster driver easily and incorporate it in my player/opl driver lib (,which is not public yet).

That, I can (soon) do ! :)

I have a bit of interface cleaning to do but assuming isa_bios.prg is in the auto folder it should be as simple as:

Code: Select all

isa_t* isa;
Getcookie('_ISA', &isa);
isa->outp(0x388, somedata)

or a bit cleaner yet, get the device details from the pnp map:
(non-pnp devices can be manually added to the map too, through the cfg file)

Code: Select all

// get first installed device with id <pnp_id>
isa_dev_t* dev = isa->GetDevice(pnp_id, 0);

// write <somedata> to register <reg> in the devices first io-range
isa->outp(dev->ports[0] + reg, somedata)

Untested on anything but my computer, but should/may autodetect and work on Hades and Milan too if I understood their memorymaps correctly.
Panther/2 or those VME adapters are a bit tricker to autodetect since they change memorymap depending on which graphicscard you use - but since you can override bus details manually in the config file you could probably make it work on anything sensible.

If you rather write directly instead of calling the API you can too. It requires a bit more care and checking the flags on how the bus is wired up though. and possibly have different codepaths for different machines. same as pci_bios.
(though in reality, all machines can do "little endian lane swapped" access as far as I can tell)