The RoBo Rally Computer

One of the more famous, at least in the USA, of the early rally computers was the “RoBo”.  The RoBo was a huge, but capable rally computer that was designed by rally participants, Al Ross and Roger Bohl.  The name RoBo came from the first two letters of both of their last names.  While the units were design by these two people, the units were manufactured by Heuer Time Corporation in Stamford, Connecticut.  The RoBo rally computer is shown below.


The RoBo Rally Computer

The RoBo is a rather big unit 17-1/2″ wide, 5-1/2″ high and 7-1/4″ deep.  It should be borne in mind that this rally computer was available from about 1968 to about 1974.  All computers, including rally computers, have got massively smaller since that time.

The following advertisement provides a description of some of the features of this rally computer.


Advertisement For The RoBo

The last two paragraphs of the advertisement are interesting.  The second last paragraph notes that the Heuer/RoBo did not come with an output display beyond the odometer display.  Users would need to have their own read out equipment or to buy the Heuer digital computer display shown at the bottom right of the advertisement.

The last paragraph notes that the Heuer/Robo computer costs less than an “ordinary” computer.  In the 1970 era I don’t even know what an ordinary computer was.  I was in engineering school at that time and ordinary computers were the size of household furnaces and housed in huge air-conditioned rooms. Why this statement was made is not clear to me.

The image below shows the back side of the RoBo.  The name plate notes the US corporate headquarters of the Heuer Electronics Corporation.  The “Accessories” outlet would appear to be the location into which a readout unit would be plugged into the RoBo.  The “Pickup Input” is the location where the wheel sensor is connected to the RoBo.


Back View Of The RoBo

I have never had the opportunity to use a RoBo, but I will attempt to explain how I think that these units were used in rally conditions.

On the left front of the RoBo there is a “Corrected Odometer” display.  The distance is displayed to three places of decimal.  It appears that the odometer reading can be advanced by pushing the “Fast Add” button.  When this “Fast Add” button is pushed not only is the odometer corrected to time output is also corrected to account for the extra distance traveled.  I don’t see where distance can be taken from the odometer, but it appears that distance could be taken off the odometer by momentarily turning the RoBo off or rotating the rotary dial on the front of the RoBo to “Off”.  For example if the odometer is running “long” and the car is approaching a point with a known mileage, say 24.32 miles, then turn the Robo off when the odometer says 24.32, then turn it back on as you pass the known point thus effectively taking distance off the odometer.

The instructions note that each one of the digits that make up the “Corrected Odometer” display can be adjusted separately.  This is useful when starting from a fixed mileage location.

To the right of the “Corrected Odometer” are two rows of dials labelled “Factor A” and “Factor B”.  These factors are the speed factors.  Rather than directly entering the required average speed, the navigator would enter the speed factor expressed as minutes per mile.  The two rows, Factor A and Factor B, allows the navigator to enter the current required average speed as one factor and then enter the speed factor for the next required average speed.  The toggle switch to the right of the two factors allows the navigator to switch between active speed factors.  By matching the minutes per mile with the odometer reading, the RoBo can provide a continuous valve of the what the time should be when at a given distance from the starting of the leg.  Comparing this calculated time with the actual time will allow for the navigator to determine if they are running ahead of time, behind time, or right on target.

The operation of the “Correction” set of dials is not clear to me.  The input value appears to be the number of pulses per mile. It is not clear how these dials are positioned to calibrate the odometer.  The correction factor reportedly can correct the odometer by a factor of +/- 10% in increments of 0.1%  What is not clear to me is the function of the left-most dial.  I think that it controls the decimal point, but I’m not sure.

Above the “Correction” dials is a rotary switch which controls to overall operation of the RoBo rally computer.

To the right of the rotary dial are two displays.  The upper display is for the “Off Course Time” which will total the amount of time that you have lost until you regain the course, assuming that it was activated by the navigator when the car went off the course.  Also if the navigator pushes the “Add Time” button, then the navigator can add time to the computed time in order to account for transits or pauses.  The lower display is an auxiliary odometer that is used for measuring off course distances.

The following description of the RoB0 provides further information about the operation of the RoBo rally computer.


The RoBo rally computer strangely did not come with an output display built in.  As shown in the advertising page an optional Model 1015-3 could be purchased which provided a digital readout.  Although not stated it seems that the information displayed in the digital read out is the calculated time.  Therefore the navigator would have to have a companion time clock in order to compare the calculated time with the actual or real time in order to determine if the car is on time or not.

The RoBo rally computer shown below appears to be connected to a Zeron clock that was presumably used for the RoBo digital output display.


Robo Rally Computer With A Zeron Output

Some users of the RoBo rally computer chose other forms of time keeping.  An example of this is the Sheetz-Gull rally computer readout unit as shown below.


Sheetz-Gull Rally Computer Readout

The instruction page for the Sheetz-Gull rally computer readout is presented below.  It seems that the Sheetz-Gull rally computer readout has a timing display approach that is almost identical to the Halda Speedpilot with respect to matching the car’s pace to the real time using a matching clock hands approach.


Instyruction Page For The Sheetz-Gull Rally Computer Display

One of the things that I’ve noticed about the RoBo rally computer is that it was very expensive.  The base RoBo rally computer was $425 while the matching output display was $160.  This combines to $585 in, say, 1970.  At that time the tuition that I paid for half of my first year at the University of Waterloo (Canada’s best engineering school) was $500!  You could buy a new Plymouth Road Runner for about $3000 or about 5 or 6 times the cost of this rally computer.  Today you would be lucky to get an equivalent new car to the Plymouth Road Runner for $30,000.  For current proportion this would be like paying $5,000 or $6,000 for a rally computer!  It would seem that only the well-heeled or well sponsored rally competitors would have been able to afford these RoBo units.

As I noted I have never used this unit, therefore I can’t speak to its performance in that era.  I would welcome input from those who might have had personal experience with this unit.  I want to thank David Scothorn from England for providing much of the base information that I used in this post.  David has recently acquired a RoBo rally computer as part of his interest in Heuer products and rallying.

If you have any questions or comments about this post, then please leave a comment below or you can send me a private email message at the following address: shanna12 at comcast dot net

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One Response to The RoBo Rally Computer

  1. bobdenton says:

    Great article on a “blast from the past” computer. I still have an old Stevens. As I continue to restore my vintage 1956 Alfa 1900 rally car I still went more for show with a Halda and a matched pair of Heuers. Keep up the wonderful articles.

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