to the surface of the holding area by expanding the depth of the pocket 320 fig4 f illustrates a cartridge in which the hole 445 does not cut into the end surface of the cartridge in both cases the keying structure 455 has been left completely intact allowing for the cartridge to be properly installed on the carriage fig3 c illustrates a perspective view of a chip mounted into an enlarged chip pocket the replacement chip 310 a has a chip package 312 a located on a surface opposite the surface having the electrical contacts the chip package 312 a is too thick preventing the replacement chip 310 a from fitting in the chip pocket 320 to sit flush with a surface 332 of the cartridge housing 330 therefore the chip pocket is expanded 360 by the method described above or by one or more of the methods that are described below to allow for the replacement chip 310 a to sit lower the spring housing 340 is located on the printer carriage and includes one or more spring contacts 350 in operation when the cartridge is inserted into the carriage the spring contact 350 is pushed against the cartridge housing 330 at the chip holding surface 332 because the replacement chip 310 a does not extend too far above.