Although not technically a clone, Quadram produced an add-in ISA card, called the Quadlink, that provided hardware emulation of an Apple II+ for the IBM PC. The card had its own 6502 CPU and dedicated 80 K RAM (64 K for applications, plus 16 K to hold a reverse-engineered Apple ROM image, loaded at boot-time), and installed "between" the PC and its floppy drive(s), color display, and speaker, in a pass-through configuration. This allowed the PC to operate in a dual-boot fashion: when booted through the Quadlink, the PC could run the majority of Apple II software, and read and write Apple-formatted floppies through the standard PC floppy drive. Because it had a dedicated processor, rather than any form of software emulation, this system ran at nearly the same speed as an equivalent Apple machine. Another company, Diamond Computer Systems, produced a similar card called the Trackstar, that had a dual pair of 6502 CPUs, and ran Apple II software using an Apple licensed ROM. The original Trackstar (and "128" and "Plus" model) was Apple II Plus compatible, while the "Trackstar E", Apple IIe compatible. The original offered 64K of usable Apple II RAM, while the other models 128K RAM (192K is on board, with the additional memory reserved for the Trackstar itself). The original Trackstar also contained a Z80 CPU, allowing it to run both Apple DOS and Apple CP/M software, however the newer Trackstar models did not, and thus dropped CP/M compatibility. The Trackstar also had a connector allowing use of an actual Apple floppy drive, which enhanced its compatibility with software that took advantage of Apple hardware for copy-protection.