                        CARTEST UPDATE LOG
                        ------------------

Version 2.1,  August 1, 1993

MORE CARS:

o     Version  2.1  comes with a database of 472 cars,  162  more 
      than in Version 2.0.

NEW FUNCTIONS:

o     Fuel economy computations simulate the EPA City and Highway 
      driving  cycles. Curves of constant speed vs. MPG  in  each 
      gear are also plotted. You can also examine the EPA  cycles 
      as  defined by the EPA. Requires a new vehicle  data  item, 
      the engine compression ratio.

o     Optional  simple  simulated sound  effects  during  vehicle 
      acceleration.

o     Acceleration  results and data for a car may be  output  to 
      a printer or to a disk file.

o     You  may  produce and print a sorted list of all  the  cars 
      ranked  in order of acceleration performance  for  selected 
      speeds or distances.

o     The launch parameters for all the cars can be optimized for 
      selected  speeds or distances using an 'Optimize All  Cars' 
      function.

o     The  CarTest  data  file may be  expanded,  contracted,  or 
      reformatted (if corrupted by hardware fault).

o     Two  CarTest  data  files may be  combined  using  a  merge 
      function.

o     Help screens may be output to a printer or to a disk file.

o     The  Up and Down arrow keys can be used to scroll the  help 
      screens up or down one line at a time.

o     The  time  of day clock in the upper right  corner  of  the 
      screen may be switched on and off.

REVISED DISPLAYS:

o     Acceleration  curve also plots the vehicle acceleration (in 
      G's) in addition to the time-to-speed data.

o     The drag race screen also displays the vehicle acceleration 
      in G's.

o     The drag racing vehicle outlines have been revised.

IMPROVED ALGORITHMS:

o     The  vehicle  launch algorithms have been improved  with  a 
      more refined model of wheelspin and tire 'hookup.'

o     The  tire drag model has been improved using a  new  method 
      substantiated by measured data.

o     More  flexible horsepower curve determination.  Previously, 
      some  power  curves  could  not  be  defined  with  certain 
      horsepower, torque, and rpm values.

BUG FIXES:

o     In  the drag racing mode, some automatic transmission  cars 
      used  an improper launch technique making them  incorrectly 
      appear faster than when accelerated as single vehicles.

INTERNAL IMPROVEMENTS:

o     The  data file containing the help screen text is  supplied 
      in a compressed format requiring less disk space.

o     Internal file handling is more efficient.

o     A reduction in memory requirements, 462 K vs. 484 K.

o     Executable  code provided with two separate  overlay  files 
      with more efficient execution.


Version 2.2,  November 1, 1993

CAR DATA FILE:

o     Version 2.2 comes with a database of 505 cars, 33 more than 
      in Version 2.1.

o     Some  data  corrections  to existing data found  to  be  in 
      error.

NEW FUNCTIONS:

o     Comparison  tests  functions: standing  start  acceleration 
      curves,  engine flexibility curves, performance  comparison 
      analyses.

o     Parameter Sensitivity analyses.

REVISED DISPLAYS:

o     Some revised instruction placement locations.

IMPROVED ALGORITHMS:

o     Better clutch engagement algorithms for gears 2 and above.

o     Better  estimate  of  rotational inertia  in  initial  time 
      interval.

o     Improved method for determining power curves.

o     Differentiation  of drive wheels from non-drive  wheels  in 
      determining wheel radius.

BUG FIXES:

o     Fix initialization error in real-time acceleration graph.

INTERNAL IMPROVEMENTS:

o     No  repeat of beginning and end of data messages on  screen 
      displays.
 
o     Improved error recognition routines.

o     Improved handling of out of bounds values for parameters.

o     Establish minimum rpm for sound effects.

o     Help  screens printed in more logical sequence with a  page 
      break for each new screen.

o     Not an improvement, but memory requirements now 487K.


Version 3.0,  July 20, 1994

CAR DATA FILE:

o     Version 3.0 comes with a database of 580 cars, 75 more than 
      in Version 2.2.

o     Some  data  corrections  to existing data found  to  be  in 
      error.

NEW FUNCTIONS:

o     Best  launch RPM optimization now shows plot of curves  for 
      0-vel or 0-dist.

o     Entry of a single letter for faster traversal through data.

o     Initial launch optimization criteria is now 0-60 mph.

o     List cars with car-specific parameters utility.

o     In comparison tests, add plots of accel vs. RPM for  engine 
      flexibility.

o     Slalom speed and lateral acceleration.

o     Cars  can  now be ranked by: top  speed,  mileage,  skidpad 
      lateral acceleration, and slalom speed.

o     Add a sequential turbocharger engine type.

o     Rank cars can now be listed in alphabetical order.

o     Plot both EPA schedules on same screen.

o     Option in comparison tests for standing start  acceleration 
      and engine flexibility to plot all three graphs on the same 
      screen.

REVISED DISPLAYS:

o     Blue plot backgrounds with borders.

o     Rank cars is now in comparison test menu.

o     Better  handling of displays if car will not reach  certain 
      speeds.

o     Plot of power in gear plots losses to top speed only.

o     Can plot horsepower and torque on same screen.

IMPROVED ALGORITHMS:

o     Use  a  variable  coefficient of friction  due  to  loading 
      variances.

o     Better grade correction handling in headwinds.

o     Automatic zero-value parameter sensitivity handling.

o     Better initial stall speed calculation.

o     Better parameter limits checks.

o     Better model of all-wheel drive starts.

BUG FIXES:

o     Fix missing top speed in performance comparison analysis.

o     Correct  v.  2.2  error  with  wheelspin  maximum   allowed 
      acceleration.

o     Aerodynamic  drag  in headwinds  was  sometimes  calculated 
      incorrectly.

INTERNAL IMPROVEMENTS:

o     Faster execution of drag race function with better  linking 
      specification.

o     Memory requirements now 477K.


Version 4.1,  July 1, 1995

CAR DATA FILE:

o     Version 4.1 comes with a database of 831 cars (10/14/97).

o     Some  data  corrections  to existing data found  to  be  in 
      error.

NEW FUNCTIONS:

o     Track testing function with 50 defined race tracks.

o     Track testing added to comparison test menu.

o     Can rank all cars according to race track lap times.

o     Can turn on/off all sounds from utility menu.

o     Add  a plot of acceleration versus vehicle speed in  engine 
      flexibility curves section.

IMPROVED ALGORITHMS:

o     Lateral  acceleration  and  slalom  speed calculations made 
      more consistent.

o     Rolling  starts now will recognize wheelspin if  it  should 
      occur.

BUG FIXES:

o     Extremely skinny tires led to incorrect tire thrust values.

o     Front-wheel drive cars with too much power (about 1000  hp) 
      launched improperly.

o     Compariso o la time fo 'Rac Trac La Tim 
Comparisons wa sometime incorrec (1/30/9 or earlier 
date versio only).

INTERNAL CHANGES:

o     All executatble code contained in one file, CT.EXE. No more
      overlays.

o     Memory requirements now 521K.

Version 4.5,  January 1998

CAR DATA FILE:

o     Version 4.5 comes with a database of 850+ cars.

o     Some  data  corrections  to existing data found  to  be  in 
      error.

NEW FUNCTIONS:

o    Optio o workin i Englis o Metri unit (Utilitie 
menu).

o     Optio statu displa o mai screen.

o     Real-Tim executio spee limi optio (Utilitie Menu).

o     Ca-specifi parameter no contai optiona use-
programmabl shif points.

o    Ca-specifi parameter no contai optiona use-
programmabl latera acceleration 

BUG FIXES:

o     Fixe rese proble i track testing.

INTERNAL CHANGES:

o    Al progra interna tex containe i a externa file 
CT.TXT.

o     Numbe o car tha ca b displaye i scrollabl windo 
increase t 130 (fro 1000).

o     Memory requirements now 518K.

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