How much internal memory does the HP DesignJet 500 come with, and can it be expanded?

The HP DesignJet 500 comes standard with 16MB of internal RAM. To expand memory, you must first purchase an optional HP-GL/2 Accessory card (PN C7772A), then add either 64MB (PN C2387A) or 128MB (PN C2388A) of memory to the card for large file processing and improved printing. (Page 13)