Obtaining Sound Output

Non-soundcard Sound

If you do not have an RPC with 16-bit sound, then you are likely to find that your PC card is mute, although it is possible to get sound from it! But only if you have a 1st generation PC card.

This is all done using the two mysterious pins which are located next to the 486 processor. These are outputs for a PC like speaker. I have connected some external speakers for use with 'normal' RPC sound which means that the internal speaker is now unused, so I unplugged it from the connector on the motherboard and plugged it into the two pins on the PC card. You may find that the lead to the speaker may need extending.

The second generation PC cards (Aleph One 5x86, Acorn DX2/66, DX4/100, 5x86) do not have the two pins fitted. Although the parts could be added (two surface mount resistors and the pins themselves) Aleph 1 make no guarantee that they will work.

Disclaimer: The modification I have described above has worked on my RPC but you should do it at your own risk.

Once this has been done you will find that from DOS you will start to get the odd sound coming from your speaker and a few games and others will use the speaker if selected. But to get sound from windows 3.1 you need to use the windows speaker driver. This can be found at HENSA and many other PD sites on the internet, located in the PC section. This is supplied with an install routine which will enable you to make a simple transition to sound under windows 3.1. But as the sound is controlled by the processor and not by dedicated hardware you will find that this is fairly slow in use.

Soundcard Sound

If you have a RPC700 or a RPC600 with a 16-bit sound upgrade then it is possible to use the RPC hardware as a limited soundblaster emulator. Software is supplied with the newer versions of the PCx86 software which mean that the 486 processor is no longer doing all the work in driving the speaker and a much wider variety of sound control is now possible. The emulation works quite well from within windows due to there being a standard interface for sound drivers (a rare thing in the PC world) and works to a limited extent with programs from DOS.

PC Sound Professional

Even with the soundcard, the sound output still isn't quite like that on a normal PC with a good soundcard. PC Sound Professional from RComp. This offers proper SoundBlaster® 16 audio and MPU401 MIDI music (if you have MIDI support, eg Software Synth). This is compatible with DOS, Win 3.1 and Win 95.

More details are on the PC Sound Pro WWW page.