function DescribeComputer
% DescribeComputer prints out several lines of text about the computing
% environment that your programs are running in. It is called by many of
% the programs in PsychTest to document the computing environment of the
% test. E.g. try running ScreenTest. Also see DescribeScreen and 
% DescribeScreenPrefs.
 
% 8/1/98  dgp Print PsychtoolboxDate.
% 4/12/99 dgp Suggest calling Screen('Preference','Backgrounding',0)
% 12/23/99 dgp Report whether screen saver is present.
% 12/23/99 dgp Report if VM is on.
% 1/24/00 dgp Updated for enhanced ScreenSaver.mex.
% 1/26/00 dgp Updated for Screen Preference Available.
% 1/29/00 dgp Suggest upgrading to Mac OS 8.6 or better, to get UpTime.
% 1/30/00 dgp Omit stuff that's no longer interesting: fpu,cache,pci.
% 2/6/00  dgp Updated to use new struct return arg from Screen Computer.
% 3/14/00 dgp Test for serial port arbitration.
% 6/17/00 dgp Test for mirroring.
% 8/22/00 dgp Distinguish good new from bad old version of Keyspan Digital Media Remote.
% 2/24/02 dgp Warn against PopChar Pro.
% 4/9/02  dgp Add explanation to VM warning.
% 4/13/02 dgp Added ~MAC2 conditional.
% 4/29/02 awi Replaced ~MAC2 with Win conditional, added detection and display of info.  
% 5/5/02  dgp Streamlined the OS9 report, commenting out the default case for QuickTime, 
%             screen save, UpTime, and serial-port arbitration.
% 6/2/02  dgp Extend initial line to be 74 characters wide, to match DescribeScreen.
% 6/23/02 dgp Remove initial '\n'.
% 12/20/04 awi  Added OS X section.
% 1/29/05 dgp  Cosmetic.
% 3/05/06 awi Fixed a case error in GetSecs call. 
 
if IsWin
    cpuNumNames={'Single', 'Dual', 'Triple', 'Quad', 'Five', 'Six', 'Seven', 'Eight', 'Nine', 'Ten', 'Eleven', 'Twelve' ...
            'Thirteen', 'Fourteen', 'Fifteen', 'Sixteen' };
    comp=Screen('Computer');
    %****** VALKYRIE with Intel Pentium Pro|Pentium II, Windows 2000 Service Pack 1 ****    
    fprintf('****** %s running %s %s ******\n',comp.computerName,comp.OSName, comp.OSRevision);
    % Dual CPU with 255MB RAM, 61MB free and 76% load.
    fprintf('%s %s %s with %dMB RAM, %dMB free and %d%s load.\n', cpuNumNames{comp.CPUCount}, comp.CPUArchitecture,comp.CPULevel, ...
        round(Bytes('SystemRAM')/2^20), round(Bytes('SystemRAMFree')/2^20), round(Bytes('SystemRAMLoad')*100), '%'); 
    fprintf('DirectX %d.%d release %d.%d\n',comp.directxVersion.major, comp.directxVersion.minor, comp.directxVersion.release,...
        comp.directxVersion.build);
    % Psychtoolbox 2.45, 1 August 2001, Matlab 6.1.0.450 (R12.1)
    fprintf('Psychtoolbox %g, %s, Matlab %s\n',PsychtoolboxVersion,PsychtoolboxDate,version);
    return;
end
 
if IsOSX
% ************************ Denis Pelli on Weber ************************
% Single-CPU PowerBook G4 17" at 1.50 GHz
% Memory 1.00 GB at 166.40 MHz. 33 Mflop/s
% Mac OS 10.3.8, MATLAB 7.0.1.24704 (R14) Service Pack 1
% Psychtoolbox 1.0.5, ?? February 2005
    
    % get all the information
    c=Screen('Computer');
    thisMacTytpe=MacModelName;
    pyschtoolboxV=PsychtoolboxVersion;
    pyschtoolboxD=PsychtoolboxDate;
    matlabV=version;
    quicktimeV=AppleVersion('qtim');
    
    %line 1
    unpaddedLine=[c.processUserLongName ' on ' c.localHostName];
    padtoWidth=70;
    lineChars=length(unpaddedLine);
    halfStars=floor((padtoWidth-lineChars)/2) - 1;
    outputLines{1}= [repmat('*', 1, halfStars) ' ' unpaddedLine ' ' repmat('*', 1, halfStars)];
    %line 2
    numCPUsStrings={'Single-', 'Dual-', 'Triple-', 'Quad-', 'Five-' 'Six-' 'Seven-' 'Eight-'};
    numCPUsString=numCPUsStrings{c.hw.ncpu};
    roundedSpeed=NameFrequency(c.hw.cpufreq);
    outputLines{2}=[numCPUsString 'CPU ' MacModelName ' at ' roundedSpeed ];
    %line 3
    outputLines{3}=['Memory ' NameBytes(c.hw.physmem) ' at ' NameFrequency(c.hw.busfreq) sprintf(', %.0f Mflop/s',FlopPerSec/1e6)]; 
    %line 4
    outputLines{4}=[c.system ', MATLAB ' version ];
    %line 5
    outputLines{5}=['Psychtoolbox ' PsychtoolboxVersion ', '  PsychtoolboxDate];
    %line 6
%     outputLines{6}=['QuickTime ' AppleVersion('qtim') '\n'];
 
    for i=1:length(outputLines)
        fprintf('%s\n',outputLines{i});
    end
   
end %if IsOSX
 
 
function r=FlopPerSec
    % r=FlopPerSec
    % Measure flop/s for FFT2. The ops increase as n*n*log(n). We first do n=8.
    % If the machine is fast (i.e. not using SoftwareFPU) then we do n=256, a typical
    % image width.
    r=fps(8);
    if r>10000
        % use bigger matrix if machine is fast
        r=fps(256);
    end
return
 
function r=fps(n)
% r=fps(n)
f=0;
t=GetSecs;fft2(1);  % load functions into memory
x=magic(n);
if exist('flops','builtin')
    f=flops;
end
for i=1 % precompile
%   Priority(7);
    t=GetSecs;
    fft2(x);
    t=GetSecs-t;
%   Priority(0);
end
if exist('flops','builtin')
    f=flops-f;
else
    fft2flops=[94 572 2712 12240 54752 244288 1085824 4799744 21081600 91997184]; % as reported by MATLAB 5.2.1
    f=fft2flops(round(log2(n)));
end
r=f/t;
return