Ym2151

[Thrashbarg]

Hi,

I've found myself a YM2151 and have fitted it to the 8080 as an improvement over the AY-3-8910/YM2149 - problem is I can't get it to sound. The documentation for it is very obscure. Can anyone help?

I'm positive the wiring is fine, all control signals are correct when I single step the program.

Here's the table which I'm sending to the YM. The first byte is the address, the second is the data.


DB 040H, 001H ; DT1 = 0, MUL = 1
DB 0C0H, 000H ; DT2 = 0
DB 080H, 00DH ; ATTACK RATE
DB 060H, 000H ; TOTAL LEVEL

DB 020H, 0C0H ; LEFT AND RIGHT ENABLED
DB 028H, 04AH ; NOTE MIDDLE C
DB 030H, 000H ; KEY FRACTION
DB 038H, 000H ; PMS = 0

DB 008H, 008H ; ACTIVATE NOTE CHANNEL 0


Thanks.

 

[billdeg]

have you tested the speaker?

 

[grant]

This project sounds pretty coo. The song mp3 file you posted was impressive.

Do you have any details or software on this project? I might be interested in building an S-100 card version of it for the Altair.

Good work.

 

[Thrashbarg]

have you tested the speaker?

actually the socket on the card had a bridge to ground on it...

Do you have any details or software on this project? I might be interested in building an S-100 card version of it for the Altair.

It's written in PL/M. Here's the code for the MIDI interface (just a standard 6850 with a speed of 2MHz).

http://kaput.homeunix.org/~thrashbarg/midi.plm

PL/M is available here

http://cpm.z80.de/download/plm80s.zip

 

[grant]

You hooked the YM2151 to a 6850, which was then connected to your 8080 over serial?

Do you have any rough schematics on the project?

Grant

 

[Thrashbarg]

The 8080 is the centre of the computer. The 6850 and YM2151 are peripherals. The software reads from the 6850, interprets the MIDI signals received and sends the appropriate commands to the YM2151.

I'll draw up some schematics soon.