shown may also be included in the motor components 64 a and 64 b to regulate the rotational speed of the platen 48 as needed to advance the stock a spacer block or option block 21 is disposed between sides 22 b and 22 b u2032 of the housing 20 spacer block 21 includes an internal cavity 21 a defined therein that is configured to house drive motor assembly 64 pcba 130 and other electrical components described below as best shown in fig8 a 8c the spacer block 21 may be replaced with an option block 121 which includes a smart card reader writer 250 or a magnetic card reader writer 350 other types of readers are also contemplated rfid readers barcode scanners aztec code scanners etc as can be appreciated during manufacturing and assembly the user indicates what type of reader is desirable and simply mounts that particular reader in place of the spacer block 21 this greatly facilitates assembly in addition combination readers may also be substituted for the spacer block 21 e g a magnetic card reader 350 and smart card reader 250 or any other combination of the above mentioned readers pcba 130 is also housed within spacer block cavity 21 a and is configured to control the operation of the printer 10 and print head 70 and regulate the charging of the battery as mentioned above the.