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1992-12-05
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MODPLAY ********* (C) Mark J Cox
MODPLAY ** 1990/1991
MODPLAY *******
MODPLAY **************
Amiga four─channel sound module player for PC's
Hardware devices for great sound output!
I. CONTENTS
─────────────────────────────────────────────────────────
How to make:
Mono output from a parallel port for about 5 pounds
Mono output from a parallel port for around 1 pound
Stereo from one parallel port for about 12 pounds
A +5v power supply
A 22W amplifier
This document has been supplied with MODPLAY or MODRES and the
license agreement attached to the MODPLAY documentation applies
to this file.
I. INTRODUCTION
─────────────────────────────────────────────────────────
MODPLAY will play modules through the PC Speaker as mentioned above, via
an D to A converter on any of the three possible parallel ports, in stereo
if you have an D to A converter on both LPT1 and LPT2 (this sounds really
good) and also through a special board that plays stereo from one
printer port ("stereo─on─1")
1. HOW TO MAKE A D/A CONVERTER FOR FIVE POUNDS
─────────────────────────────────────────────────────────
A simple circuit for HiFi quality sound needs only a few components (and
this circuit will work with other software). It even sounds better than
a Sound Blaster for sampled output!
You need:
IC1 a ZN426E (about 3 pounds) (Ferranti or Plessey are UK manufacturers)
C1 a 10micro-farad electrolytic capacitor (10V or greater)
C2 a 4.7micro-farad electrolytic capacitor (10V or greater)
R1 a 380ohm resistor (5%, 1/8W)
CON1 a phono socket for connecting a lead to your amplifier
CON2 a 25 way male D-type connector for your parrallel port
A bit of 10 way cable - or 10 short wires.
A +5v supply
Zn426e +5V
D-type pin no \ ┌────────┐ │
(2) D0 ───┤9 14├──┤
(3) D1 ───┤10 │ ┌┴┐
(4) D2 ───┤11 │ │ │ 390Ω
(5) D3 ───┤12 │ └┬┘
(6) D4 ───┤13 5├──┤
(7) D5 ───┤1 6├──┤ +
(8) D6 ───┤2 4├──│────────┤█────> TO AMPLIFIER
(9) D7 ───┤3 7 │ │ 10µF
└────┬───┘ +╧ (may not be needed)
│ 4.7µF█
│ │
(25) GND ────────┴──────┴────────────── GND
2. USING A DIFFERENT DAC
─────────────────────────────────────────────────────────
Lots of people have found that they cannot get the ZN* chips outside
the UK - so heres a circuit that will do the same as above..
Use a DAC0800 or DAC0801 or DAC0803 from National Semiconductors...
DAC 080x
Parallel Port Pin ┌────────┐0.01µF 0.1µF
(2) D0 ───┤12 16├──┤█────┤█──────┬─── GND
(3) D1 ───┤11 │ │
(4) D2 ───┤10 15├─────────██████─┘5kΩ
(5) D3 ───┤9 │
(6) D4 ───┤8 14├─────────██████─┐5kΩ
(7) D5 ───┤7 13├────────────────┤
(8) D6 ───┤6 2├──┤█────────────┴── +5V
(9) D7 ───┤5 3 1 4├──────────┤█────> TO AMPLIFIER
└──┬─┬───┘0.1µF + 10µF
└─┤ (may not be needed)
│
(25) GND ────────┴──────────────────── GND
The 0.01uF and 2x 0.1uF capacitors are Ceramic. Resistor values
not critical
2. GETTING A +5V POWER SUPPLY
─────────────────────────────────────────────────────────
Catalogues such as MAPLIN (uk) provide simple circuits for obtaining
a +5v power supply (it only has to be 100mA maximum). Alternatively
you could tap +5v off the keyboard connector or use 3 1.5volt
batteries (or even 4 1.5volt batteries with two diodes in series to
drop the voltage). In fact, anything that produces a voltage in the
range 4.5 ─ 5.5 volts. (in fact you can even tap +5v from the game
port). Don't forget to connect the 0v of your power supply to the GND
rail shown.
Heres a simple circuit for +5v from mains. Mains voltage is lethal
so always get a qualified person to make this if you are unsure. Make
certain that the mains voltage is completely isolated from the computer
side and that it is impossible to touch - If you don't want to take the
risk then don't make this circuit.
┌───────────┐ ≈┌───┐+ ┌──────┐
│ │ │ B ├─────┬───────┬─────┤ 7805 ├────┬────── +5V
───────┤Step down ├──────┤ R │ │+ │ └──┬───┘ │+
Mains │transformer│ 6V │ I │ ═╪═ C1 ═╪═ C2 │ ═╪═ C3
│to 6VAC │ AC │ D │ │ │ │ │
───────┤ ├──────┤ G │ │ │ │ │
│ │ │ E ├─────┴───────┴────────┴────────┴────── 0V
└───────────┘ ≈└───┘-
C1 1000 µF electrolytic capacitor (Circuit from Kenneth
C2 0.1 µF ceramic capactitor Aaron, Israel)
C3 100 µF electrolytic capacitor
BRIDGE any diode bridge
3. HOW TO MAKE AN EVEN CHEAPER D/A
─────────────────────────────────────────────────────────
For the price of 20 1% resistors and a plug, with no power supply
needed you can make a D/A converter that sounds close to the IC
one above (it seems only the UK can get a Plessey ZN426E)
You need one plug for your amp, one for your parallel port and
9 20k and 9 10K resistors
Use 1% resistors if possible ─ and 20k sound much better than 22k
Printer Port:
signal pin 20k 20k
D0 2 >───░░░─┬─░░░──0v
20k ░ 10k
D1 3 >───░░░─┤
20k ░ 10k
D2 4 >───░░░─┤
20k ░ 10k
D3 5 >───░░░─┤
20k ░ 10k
D4 6 >───░░░─┤
20k ░ 10k
D5 7 >───░░░─┤
20k ░ 10k
D6 8 >───░░░─┤
20k ░ 10k
D7 9 >───░░░─┤
20k ░ 10k 100nF
├──────┤█────> TO AMPLIFIER
░ 10k
GND 20 >───────┼────────────>
0v
Thanks to Harry Stox for the above circuit. Again, make sure all
the 0v lines are connected together. The 100nF capacitor may not
be needed, try removing it if this circuit sounds poor.
4. STEREO-ON-1 BOARD
─────────────────────────────────────────────────────────
It is possible to play in stereo with only one parallel port (MODPLAY
version 2.00 onwards) using the circuit below. MODPLAY will
automatically detect this circuit if it is present and work out what
address it is at ─ so you can plug it into any of your parallel ports.
MODPLAY needs no further options and will default to playing through
this device. The +5v supply can be anywhere between 4.5 and 5.5 volts
so it could be run from three 1.5v batteries. (Or from four
rechargable batteries as these are only 1.2v)
* Stereo-on-1 works from MODPLAY 2.03 onwards whe