A replaceable item for a host device, such as a print substance cartridge for a printing device, stores multiple identities. For each identity, the replaceable item stores multiple authentication values, or passwords. The replaceable item selects an identity, and in response to a request for an authentication value from the host device, sends the requested authentication value for the selected identity.

A replaceable item for a host device, such as a print substance cartridge for a printing device, stores multiple identities. For each identity, the replaceable item stores multiple authentication values, or passwords. The replaceable item selects an identity, and in response to a request for an authentication value from the host device, sends the requested authentication value for the selected identity.

A printer apparatus comprises one or more ports (201.sub.1 to 201.sub.M) for receiving one or more colorant units (INK.sub.1 to INK.sub.N), and a processing unit. The processing unit is adapted to determine which one or more colorant units (INK.sub.1 to INK.sub.N) have been loaded into the printer apparatus. The processing unit is adapted to retrieve colorant information from each loaded colorant unit (INK.sub.1 to INK.sub.N), and determine an ink-set configuration using the colorant information retrieved from each loaded colorant unit (INK.sub.1 to INK.sub.N). Operation of the printer apparatus is configured according to the determined colorant-set configuration.

A toner container includes: a containing unit that contains a toner; a storage device that stores information; and an attachment unit. The attachment unit includes a cover member, a supporting member, and an insertion member. The cover member has a first projection and an insertion opening. The first projection extends in a first direction. The insertion opening is provided on the first projection and extends in a second direction. The supporting member has a first depression and a through opening. The first depression extends in the first direction and allows the first projection to be inserted into the first depression. The through opening extends in the second direction and is in communication with the first depression. The insertion member is inserted into the through opening and the insertion opening in a state where the storage device is positioned between the cover member and the supporting member.

An electrophotographic image forming device includes a replaceable unit that has a reservoir for holding toner. A circuit board is mounted within a pocket on a first side of a housing of the replaceable unit. The pocket has an opening facing a front of the housing to permit an electrical connector of the image forming device to enter the pocket and mate with the circuit board when the replaceable unit is installed in the image forming device. A first guide wall and a second guide wall are each positioned outside the pocket on the first side of the housing closer to the front of the housing than the opening. Inclined surfaces of the first and second guide walls are angled to move the electrical connector of the image forming device toward the circuit board during insertion of the replaceable unit into the image forming device.

An electrophotographic image forming device includes a replaceable unit that has a housing having an internal reservoir for storing toner. A circuit board retainer is positioned on an exterior surface of the housing. The retainer includes a top having an undersurface having first and second supports extending away from the undersurface of the top toward a bottom of the retainer. A mounting platform is positioned on the undersurface of the top intermediate the first and second supports and spaced apart from the bottom of the retainer. A circuit board is mounted on the mounting platform. The top and the first and second supports form an opening at the front of the retainer sized to receive an electrical connector of the image forming device for mating with the circuit board when the replaceable unit is installed in the image forming device.

An image forming apparatus comprises a fixing device comprising a heater for heating a sheet on which an image is formed and a non-volatile memory in which characteristic information of the heater is stored. The fixing device is replaceable. In a case where the fixing device is replaced, the image forming apparatus starts to supply power to the heater before completing to read the characteristic information from the fixing device replaced. Due to this, the image forming apparatus can promptly heat the heater of the fixing device than before.

A printer apparatus comprises one or more ports (201.sub.1 to 201.sub.M) for receiving one or more colorant units (INK.sub.1 to INK.sub.N), and a processing unit. The processing unit is adapted to determine which one or more colorant units (INK.sub.1 to INK.sub.N) have been loaded into the printer apparatus. The processing unit is adapted to retrieve colorant information from each loaded colorant unit (INK.sub.1 to INK.sub.N), and determine an ink-set configuration using the colorant information retrieved from each loaded colorant unit (INK.sub.1 to INK.sub.N). Operation of the printer apparatus is configured according to the determined colorant-set configuration.

An electronic component includes a processor and a memory. The electronic component has a secure platform capable of storing at least one dual key pair and a corresponding digital signature. There is also a system including a host machine and an electronic component capable of being operated by the host machine. The electronic component has a processor, a memory, and a secure platform capable of storing at least one dual key pair and a corresponding digital signature. Another aspect describes a method, which includes reading a public key from an electronic component by a host machine, verifying the public key against a stored key in the host machine, digitally signing data using a private key from the electronic component, verifying the signed data against the stored key, and using the electronic component by the host machine only if the signed data and the public key are verified.

A toner cartridge includes a customer replaceable unit monitoring (CRUM) apparatus to store error information of a toner injection process of the toner cartridge using a toner refill apparatus. Based on the error information not being stored in the CRUM apparatus, an availability of a refill operation of the toner cartridge is identified based on a predetermined first reference value and an amount of toner detected in the toner cartridge, and, based on the error information being stored in the CRUM apparatus, the availability of the refill operation of the toner cartridge is identified based on a predetermined second reference value and the amount of toner detected in the toner cartridge.