home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Collection of Tools & Utilities
/
Collection of Tools and Utilities.iso
/
sound
/
adda10.zip
/
README.1ST
< prev
Wrap
Text File
|
1992-09-24
|
4KB
|
91 lines
ADDA10.ZIP CONTENTS
-------------------
This archive describes how to build and use a simple low cost analog I/O
extension board for PC's. It utilizes the 8-bit AD7569 IC containing a
500 KHz analog-to-digital converter (ADC) and a 1 MHz digital-to-analog
converter (DAC). The card can for example be used to sample sound
with the ADC and play it back through the DAC in real time, possibly after
some `on-the-fly' digital signal processing. Files included are:
1. construction/operation description
2. electronic/layout sketch diagrams
3. Turbo Pascal 6.0 source and executable code for using the card. It
includes routines implementing two digital (guitar) sound effects,
i.e., distortion and echo. These routines demonstrate the basics of
the digital sound processing techniques used in dedicated sound effect
processors.
The files of 1. and 2. are suitable for downloading to HP Laserjet or
PostScript compatible printers.
The 12 archived files are:
README.1ST this file
DESCRIPT.TEX LaTeX text source of description (11 pages)
DESCRIPT.DVI description DVI file
DESCRIPT.HP description to be downloaded to HP Laserjet compatible printers
DESCRIPT.PS idem for PostScript printers
CIRCUIT.HP circuit diagram (HP Laserjet)
CIRCUIT.PS idem for PostScript printers
LAYOUT.HP draft of board layout (HP Laserjet)
LAYOUT.PS idem for PostScript printers
ADDA.PAS Turbo Pascal 6.0 source
ADDA.EXE executable of ADDA.PAS
EGAVGA.BGI Turbo Pascal EGA/VGA graphics driver for ADDA.EXE
For example, the DESCRIPT.HP files is printed on a HP Laserjet compatible
printer with the command
COPY /B DESCRIPT.HP PRN:
I recommend to read the DESCRIPT file first. The CIRCUIT and LAYOUT files
contain the necessary additional information to build the board.
The program ADDA.PAS was tested on EGA/VGA only. It expects the AD7569 to
operate in one of its two bipolar modes (-1.25 V --> +1.25 V or -2.5 V -->
+2.5 V). On startup a menu with six items is presented:
1. Determine highest sampling frequency
2. Plot samples
3. Reroute ADC input directly to DAC output
4. Compression/distortion
5. Echo
6. Quit
1 and 6 need no explanation. 2 plots the signal as sampled by the ADC at the
highest sampling frequency (determined by 1). Items 3, 4 and 5 expect the
following setup also given in the DESCRIPT file:
electric guitar --> pre-amplifier --> ADC input -->
PC/Turbo Pascal program --> DAC output --> guitar amplifier
The electric guitar/pre-amplifier may evidently be replaced by another
signal source. You should of course take care that the maximum ratings of
the ADC, the guitar amplifier input etc. are not exceeded.
----------------------------------------------------------------------------
I did my utmost best to exclude all errors from the contents of the
ADDA10.ZIP archive. Because I am just like you only human, the described
circuit might not work or, even worse, cause damage to other equipment.
Nevertheless, I assume no liability for this. The only guarantee I can give
you is that my board (by the way, I built the board with the electronic diagram
included in this archive; I did not create the diagram after building
the board) functions up to expectation. Of course any suggestions
to improve the correctness and intelligibility of the description, diagrams
and software are much appreciated, as are experiences of other people who
built and used the circuit. These will have their impact on possible future
versions of the archive.
----------------------------------------------------------------------------
----------------------------------------------------------------------------
Jos Groot (InterNet: jos.groot@fel.tno.nl)
van de Wateringelaan 4
2274 CH Voorburg
The Netherlands
----------------------------------------------------------------------------