Basic Facts - Physical Attributes - Functional Attributes   Physical Attributes Throughout this course, the new Monroe Classic (and 7100 series) will be used as the baseline as its design and features exceed those of all other calculators.   Enclosed Paper Roll Spare Supplies Storage Area Print Quality Ribbon Cartridge vs. Twin-Spooled Ribbons Size Keyboard Layout Key Top Size Key Top Shape Key Top Stability Touch Two-Key Rollover Electronic Keyboard Interlocks Decimal Settings Speed   Enclosed Paper Roll Most calculators (with the exception of Monroe 7130, 7140, 7150, Monroe Classic, and PRO) have an externally mounted paper roll. The most expensive component of a print/display calculator is the printer. It is also the component most likely to fail, as it is an electro-mechanical mechanism. The most common cause of printer failure is dust and dirt collecting on the paper roll and falling into the print mechanism as paper is fed through the printer. By enclosing the paper roll on Monroe’s 7100 series and Monroe Classic, Monroe protects the paper roll and extends the life of the printer. If the paper roll is external, paper roll holders (typically plastic) are mounted externally to hold the paper roll. These paper roll holders can be lost or broken during the course of use, forcing the operator to replace paper roll holders during the life of the calculator, replace the calculator or develop an inventive method for supporting the paper roll when the holders are lost or broken. The enclosed paper roll design of the 7100 series and Classic prevents the loss or breakage of the paper roll holders. Another drawback to mounting the paper roll externally is the typically cluttered desk of most users. If the paper roll is lodged against a book, stack of papers or some other object on the desk, it is likely the paper cannot advance or move through the print mechanism. As most touch operators do not look at the calculator during addition columns, they would be both surprised and disappointed to look at the tape after listing a long column of figures and see a black smudge on the tape rather than the answer. Again, the enclosed paper roll design of the 7100 series and Classic eliminates this possibility. The expected life of the print mechanism used in the 7100 series and Monroe Classic is 3 million lines of print. The enclosed paper roll enhances the ability of the printer to reach its expected life. Compared to the Monroe 2020PlusII -- and by extension many other calculators in the same print speed range whose print mechanism life is expected to be 1 to 1.5 million lines of print -- the 7100 series and Classic will last two to three times as long. Taking into account that external paper roll calculators will fail before their expected life, the 7100 series and Classic will likely exceed the expectation. Simply put, if the paper roll is on the outside, you will buy at least 3 calculators before you would wear out the 7100 series or Classic.  back to top Spare Supplies Storage Areas By enclosing the paper rolls, the Monroe Classic and 7100 series provide specially designed compartments to store an extra roll of paper tape, red/black twin-spooled ribbon and/or the ribbon cartridge.  back to top Print Quality There are a least three factors that affect the quality of print on the paper tape. The obvious one, of course, is the ribbon. Two other common factors are the paper thickness and the manufacturing variance of the printer (distance between the platen and print wheel). Monroe carefully selects both ribbon and paper supplies to optimize print quality. While both supply items are readily available, the quality of the ribbon and the quality of the paper vary greatly when obtained from sources other than Monroe.  back to top Ribbon Cartridge vs. Twin-Spooled Ribbons  Red and black print are accepted standards. This is primarily the result of accepted accounting practices where positive entries are printed in black and negative entries printed in red. Most commercial-grade calculators accept twin-spool red/black ribbons, while fewer accept a red/black ribbon cartridge. The importance of selecting a calculator that accepts a ribbon cartridge goes further than the simplicity of changing the ribbon. Ribbon cartridges cost more than twin-spooled ribbon yet are easier to change and last longer since the ribbon is enclosed to prevent drying. The economic comparison between the two should be based upon the time difference in changing the ribbon. With twin spooled ribbons the user will spend more time threading the ribbon through the mechanism. The user also will without fail get ink on their fingers and have to wash their hands after changing the ribbon. The elapsed time for changing spooled ribbons must therefore also include a stop at the water cooler or coffee machine and a brief conversation with coworkers. Considering such factors, the differential cost between a ribbon cartridge and twin-spooled ribbons weighs heavily in favor of the ribbon cartridge. The new Monroe Classic and Models 7130 and 7140 provide a choice between using a ribbon cartridge or twin-spooled ribbons.  back to top Size A common misconception applies to the size of a calculator. We look at our “tight for space desk” and naturally believe that smaller is better. When considering the size of the calculator, one must include the paper roll mounted on the outside of the calculator. Nothing can be in the area of the external paper roll in order to prevent breaking the paper roll holders and ensure the paper moves freely through the print mechanism.  back to top Keyboard Layout Today’s calculators are descended from yesteryear’s mechanical adding machines. All mechanical adding machines had adding machine controls (+, -, subtotal and total) to the right of the numeric keypad. Since the most often used functions of a calculator are addition and subtraction, adding machine controls must be located on the right of the numeric keypad. Placing them otherwise is similar to changing the location of the steering wheel of your car from left to right or worse, changing the direction of traffic to the British or Japanese system.  back to top Key Top Size The largest keys on the keyboard should be those used most frequently. For the calculator, this means the Plus Key, Minus Key, Total Key, Zero Key and Decimal Key. Actual size of these keys vary greatly from model to model and it is often what you are comfortable with that determines what size is large enough. Small keys, especially those used often, hinder touch operation and therefore productivity.  back to top Key Top Shape The shape of keys often enhances touch operation. For example, the numeric keypad (1-9) on the new Monroe Classic has cupped keys while the function keys have flat surfaces, enabling the operator to differentiate between the numeric keypad and the function keys by feel. The “5” key has a tiny dome in its center, much like a computer keyboard, which assists the operator in quickly locating the home key (5) and home row (4, 5 and 6).  back to top Key Top Stability Keys with little side-to-side play enhance touch operation by providing a surety of touch. Excessive play on the key top, or pressing key tops in locations that prohibit entry, slow down the operation of the calculator.  back to top Touch The new Monroe Classic features (IKT) Individual Keyswitch Technology. Beneath the keyboard of most calculators today is a rubber sheet. Directly beneath each key is a rubber dome (raised bump) that is part of the rubber sheet. Pressing a key contacts the rubber dome, which in turn makes contact with the printed circuit board and causes the calculator to recognize a key has been pressed. The feel of keyboards varies significantly because of factors such as material, thickness and dome shape. In all cases however, there is a minute amount of resistance to pressing the key that comes first from the dome and then the rubber sheet.  This rubber sheet technology came into prominence more than 10 years ago, replacing the then-prominent technology IKT. In designing the new Monroe Classic, Monroe has re-developed IKT as it offers the fastest, lightest and surest touch. IKT places the dome within the keyswitch itself and eliminates any resistance to a key depression caused by the rubber sheet.  back to top Two-Key Rollover Two-key rollover enhances speed in touch operation. For example, if entering the amount 12, the user presses the 1 key followed by the 2 key -- both keys are pressed. Removing the index finger from the 1 key, and then removing the middle finger from the 2 key causes both 1 and 2 to be entered. The fastest touch operators roll from the entry keys to a function key. Two-key rollover eliminates the need for pressing each key distinctly one key at a time.  back to top Electronic Keyboard Interlocks In the event two keys are pressed simultaneously, the key first sensed by the calculator will be entered. Normally it will be the key pressed with the greatest force. By not creating an Error -- which would requiring clearing on many calculators -- Electronic Keyboard Interlocks try to interpret the entry and choose the correct key depression.  back to top Decimal Settings Every calculator has one or more decimal settings. The decimal setting controls the number of decimal places desired in the total or result. The decimal selector should never limit or fix the number of decimal places contained in an entry, as its function is to determine the number of entries in the total or result. If the calculator edits entries, an operator would need to move the decimal selector to reflect the entry with the greatest number of decimal places to permit entry of all figures, and then move the decimal selector back to the desired number of decimal places in the answer before pressing the total key, requiring both additional manual and mental effort.  back to top Speed The 7100 series and Classic have a print speed of 5.0 lines per second -- the fastest speed available for calculator impact printers. Fast touch operators are often able to shut out the noise of the printer and work ahead of the printers’ ability to print. For this reason, the 7100 series and Classic have a keyboard “buffer” permitting operators to be as far as 13 entries ahead of the printer.  back to top