1. An infusion pump system for dispensing a drug to a patient comprising:
a. reservoir means for holding a drug;
b. delivery means for delivering said drug to said patient;
c. delivery control means for activating said delivery means, said delivery control system including:
(i) microprocessor means for operating said delivery means;
(ii) a set of memory modules, each module containing information defining a specific user interface; and
(iii) coupling means for accepting one of said memory modules, and coupling said one memory module to said microprocessor, wherein said microprocessor reads said information and operates said delivery means in conformance with said specific user interface.

2. The system of claim 1 further comprising input means disposed on said housing for providing patient specific data to said microprocessor means.

3. The system of claim 1 or 2, further comprising display means disposed on said housing for displaying output data.

4. The system of claim 1, 2 or 3, wherein said information defines parameters for configuring said pump to mimic a dedicated pump having specific operational characteristics.

5. An infusion pump system for dispensing a drug to a patient, said system comprising:
a. a set of memory modules, each memory module containing information defining a specific user interface;
b. a housing with memory access means for replaceably accepting one of said memory modules;
c. reservoir means mounted on said housing for holding a drug;
d. drug delivery means for delivering said drug from said reservoir to said patient; and
e. delivery control means mounted in said housing for operating said drug delivery means, said delivery control means including microprocessor means coupled to said one memory module, said microprocessor means receiving said information from said one memory module to operate said delivery means in conformance with the specific user interface defined by the information in said one memory module.

6. The system of claim 5 further comprising input means mounted on said housing for inputing patient specific data to said microprocessor means.

7. The system of claim 5 or 6, further comprising display means mounted on said housing for displaying output data from said microprocessor.

8. The system of claim 5, 6, or 7, wherein said display means includes a display panel for displaying operational instructions.

9. The system of claim 7 or 8 wherein said display means includes an alarm indicator for indicating an abnormal operating condition.

10. The system of any one of claims 5 to 9, further comprising manual control means mounted on said housing.

11. The system of claim 10 wherein said manual control means includes manual keys disposed on said housing.

12. A method of administering a drug to a patient comprising the steps of:
a. providing an infusion pump system having a reservoir with a drug, a delivery means for delivering said drug to a patient, and a delivery control means including a microprocessor for operating said delivery means, and a set of memory modules, each module containing information defining a specific user interface;
b. selecting a specific memory module; and
c. coupling said specific memory module to said microprocessor, wherein said microprocessor operates said delivery means in conformance with said specific user interface.