Daqarta for DOS
(ver 2.21)
Shareware made Abandoned Freeware


Daqarta is a general-purpose Data AcQuisition And Real-Time Analysis system. 
It allows waveforms and spectra to be viewed WHEN THEY OCCUR, rather than 
after separate collection and analysis steps. The extra-large display area 
allows maximum visibility for fine detail or distant viewing, and both axes 
are completely marked with unit divisions in a 1, 2, 5 sequence... not 
odd-ball steps or ends-only markings. Logarithmic X- and/or Y-axis scales 
may be used for spectrum display... all in real-time.


System Requirements:
- Any x86 PC (Daquarta does not require a Math CoProcessor)
- Pure DOS environment (Daqarta will -NOT- work inside Windows!)
- EGA, VGA, or better video, with at least 256K of video RAM
- 640K system RAM recommended (Daqarta typically uses less than 300K)
- Some Daqarta modes can take advantage of Extended memory
- Hard drive is recommended, but not mandatory except for DDisk recording
- An Analog-to-Digital Converter is required to capture data. 


File = dqa.zip (you will need to add a DAC driver from DRIVERS.zip)

Includes:
    DQA.EXE = main Daqarta program.
    DQA.HLP = main Daqarta Help system.
    DQA.CFG = starter configuration file.
    TXT2CAL.COM = utility for creating .CAL calibration files.
    BK4134.TXT = sample mic calibration source file.
    DQA.ICO = icon for Windows 9x shortcut.
    DQA2.ICO = alternate icon with black surround for contrast.
    DEMO.ADC = driver that requires no boards.
    DEMO.HLP = Help system for DEMO.
    MAIN.PAL = collection of sample color palettes.
    SGRAM.PAL = collection of Spectrogram palettes.
    STIM3A.GEN = Advanced Stimulus Signal Generator module.
        STIM3A.HLP = Help system for STIM3A.
        TXT2DAT.COM = utility for creating Arbitrary waveform data files.
        EXPNOTE.DAT = Arb data file containing musical note frequencies.
        COMPOSER.S3A = Setup file plays "songs" that last 100 billion years! 
    DDISK13A.DRV = optional driver for DDisk operation on non-DMA 
	laboratory-type boards.
    README.TXT = file with installation and troubleshooting tips. 


NOTE: This free version already comes with the registration key (you do 
	-not- have to go to the website to register).  The registration 
	file is "reguser.dat", and it must be kept in the program direcory).  


----------

DRIVERS.zip = DAC Drivers (for soundcards and lab-type boards)

UTILS.zip = PC Utilities that once shipped with Daqarta (-NOT- required)


============================================================================
============================================================================

DAC (Digital-to-Analog Converter):
This device (also known as a D/A) converts binary numbers into equivalent 
scaled voltages. For example, a 12-bit binary number can encode 4096 values 
(2^12 = 4096), from 0 to 4095. A typical unipolar DAC might give an output 
of 10/4095 Volt per input value, from 0 to 10 Volts.

You could make a simple DAC with a bunch of weighted resistors connected to 
the digital outputs of any parallel port such as a printer port. The smallest 
resistor would connect to the most significant bit, and each adjacent bit 
would get twice the value of the one before it. Here is a crude 4-bit DAC:

   MSB ------- 10k -------.--------------- OUT
                          |
       ------- 20k -------|
                          |
       ------- 40k -------|
                          |
   LSB ------- 80k -------'


   GND ----------------------------------- GND


This approach is rarely used inside real DAC chips, due to problems with the 
large resistor values needed as the number of bits increases, and the general 
difficulty in getting exact multiples. Instead, there are "ladder" schemes 
that use the same values over and over. The exact values don't matter as much 
as their relative matching, and this turns out to be much easier to integrate 
on a chip. A simple ladder version of the above would be:

   MSB ------- 20k -------.--------------- OUT
                          |
                         10k
                          |
       ------- 20k -------|
                          |
                         10k
                          |
       ------- 20k -------|
                          |
                         10k
                          |
   LSB ------- 20k -------|
                          |
                         20k
                          |
   GND -------------------^--------------- GND


The five 20k resistors are all matched, and are exactly twice the value of the 
three 10k resistors. If you actually build this circuit or the prior one, note 
that they assume that all of the digital outputs match and that a 0 output is 
really 0 Volts. That's not guaranteed for typical digital outputs, but for the 
simple 4-bit systems shown here it is good enough. To scale this up to 8 bits 
or more would require special buffer amplifiers to insure matching.