drive motor 200 to prevent further banknotes being fed the microprocessor 250 will also display an error message on the display 270 the microprocessor 250 may also determine other information about the banknotes such as authenticity and or fitness depending upon the information which it receives from the counter 100 the palm computing device 150 also has a key pad 280 to enable the operator to enter control commands of a conventional nature via the palm computing device to the counter 100 and or to input the values of notes whose denomination could not be determined by the apparatus fig5 illustrates a modified form of counter in which an additional memory 290 is provided this is intended to store sets of data representing master patterns or other data required for pattern analysis which can be performed by the microprocessor 220 however the microprocessor 220 will do no more than calculate a measure of similarity between the document under test and each set of data representing the master patterns and these results will be transmitted to the palm computing device 150 the microprocessor 250 will then compare each measure of similarity with each of the others to select the u201c best match u201d and then utilize a look up table or the like to determine the denomination corresponding to the identified pattern so that it can increment a count appropriately the counter 100 shown in fig2 has a single output hopper 105 the invention is also applicable however to counters sorters having multiple output hoppers and fig6 illustrates such an example with two output hoppers the fig6 counter 300 has an input hopper 401 having a base 402 with an aperture 403 through which a high friction portion 404 of.