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/* Diagram (Digiblaster v2) (Joshua) */
text copied from: [http://cpcrulezwww.freeoctoate.frde/ CPC RulesOctoate.de]
== CPC-Digiblaster v1.0 and v2.0 ==
The original Text was written by A.Stroiczek and the [[DMV]]-Verlag ([[CPC Schneider International]] 8/9'91), the hardwarelayout of the Digiblaster v2.0 was performed by [[Joshua]]/Exodus and converted by Tim Riemann (TCS-Software@gmx.de)[[Octoate]].
If we're looking at the 16bit computers like Amiga, Atari ST, Mac and PC (with a soundcard) the CPC users can be jealous.
To play 8bit samples you need a 8bit interface and a circuit which changes the values in a power value. The printer port has 8bit and a 5V power supply (Bit 7 = STROBE).
To build a D/A unit you normally need a special IC which costs about 15 to 20 DM and it needs an own power supply.
You can connect the output of the circuit directly to an amplifier.
Of course, the D/A unit needs a small demo program.
The program writes directly to the hardware of the CPC.
You can use the port with the adress address &EFxx.
Because the CPC has only a 7bit printer port (we need 8bit for the Digiblaster) we use the STROBE signal, which is inverted by the hardware, so you have to invert your sound value.
Now we want to output the value &C5:
The accu is the register A.
The pins that are not named are not connected.
How often you print out the values it is called the sampling rate.
It is possible to play some instruments at the same time. You have to add the values and divide them. I think that 4 channel sound is possible with the CPC.
''[[Face Hugger|A. Stroiczek]]''
== Diagram Differences between v1 and v2 ==
== Notes ==
* '''Caution''' Both schematics connect GND to Pin9, which works on the CPC's (unmodified) [[Connector:Printer_port|7bit printer port]], but not on (upgraded) [[8bit Printer Ports]], so better connect GND elsewhere (eg. Pin19).
* As said above, Strobe is inverted by the CPC's printer port hardware. And, when using '''unsigned''' samples, it must be actually inverted by software. However, with '''signed''' samples, that hardware feature is just perfect, and no inversion is needed.
== Diagram (Digiblaster v1) (Andreas Stroiczek) ==
[[Image:Digiblaster_diagram_v1.png]]
== Diagram (Digiblaster v2) (Joshua) ==
[[Image:digiblaster diagram.jpg]]
Parts you need:
</pre>
''Converted 1996/1998 by Tim Riemann (TCS-Software@gmx.de)[[Octoate]]'''
[[Category:Digiblaster]][[Category:DIY]][[Category:Programming]] [[Category:Printers and printer ports]] [[Category:Music and sound]]