Sound

Under4Mhz · 08-05-2022, 10:22 AM

How do I write sound for the Microbee?

I saw somewhere it's a 1bit switch connected to port 0x02 bit 6?

Is this a toggle, or 1=on, 0=off arrangement?

***ChickenMan*** · 08-05-2022, 10:41 AM

I've used this to turn sound on

LD A,05h
IN A,(02)
SET 6,A
OUT (02),A

and then use this to turn sound off

LD A,04h
IN A,(02)
RES 6,A
OUT (02),A

Under4Mhz · 12-05-2022, 07:10 PM

What port is the AY psg on? How common is it?

Ernest · 12-05-2022, 08:07 PM

(12-05-2022, 07:10 PM)Under4Mhz Wrote: What port is the AY psg on? How common is it?

Not very common at all.

If you want your game to be usable by the majority of Microbee's out there, then you will need to use the bit bash sound.

Ernest

***ChickenMan*** · 12-05-2022, 08:19 PM

Microbee never released any software to use it and we dont have any software in the repository that supports it. So, as Ernest said, not very common.

someone · 13-05-2022, 10:52 AM

There were two optional commercial sound options. One is the Beethoven which is an AY-3-8910 PSG that's plugged into the parallel User port & the other is an optional onboard chip for the Alpha Plus (Premium Series) a TI SN76489A.
The Beethoven also comes with two D9 Joystick ports.
The Beethoven has to be driven in a peculiar way and is documented in the Beethoven manual.
Some emulators emulate the SN76489 but not necessarily perfectly.

Even rarer, the microbee is also capable of driving MIDI instruments by either using a DRAM coreboard's SCC (Serial Communications Controller) with a MIDI dongle or directly attached Roland MPU-401 MIDI interface. So if you really want, you can connect & play Roland MT-32 sounds.