and software sales, but, he wrote, the Color Computer was incompatible with other Tandy software and what was available was of poor quality. "I'm sure there are at least fifty software firms out there that would love to work with the Shack", Green said, but "it seems that the Shack people are at war with their supporters and potential suppliers". Many CoCo owners agree that Tandy did not take the computer seriously. Successors A few companies attempted to carry the CoCo torch, but the lack of decent backwards compatibility with the failed to entice much of the community. Some of these systems run OS9/68k, which is similar to OS-9. Frank Hogg Labs introduced the Tomcat TC-9 in June 1990, which is somewhat compatible with the but is only able to run OS-9 software. A later version called the TC-70 has strong compatibility with the MM/1, and also runs OS-9/68K. Multi-Media One was introduced in July 1990, runs OS-9/68K on a 15 MHz Signetics 68070 processor with and a 640×208 graphics resolution as well as supporting a 640×416 interlaced mode. It includes a SCSI interface, stereo A/D and D/A conversion, an optional MIDI interface, and an optional board to upgrade the CPU to a Motorola 68340. The AT306 (also known as the MM/1B) is a successor to the MM/1 that contains a Motorola 68306 CPU, OS-9/68K 3.0, and allows ISA bus cards. It was created by Kevin Pease and Carl Kreider, and sold by Carl's company, Kreider Electronics. Peripheral Technology produced a 16 MHz Motorola 68000 system called a PTK68K-4. Delmar sold systems based on the PT68K-4 and called the Delmar System IV. The PT68K-4 has the footprint of an IBM PC and seven 8-bit ISA slots. Video is provided by a standard video card and monitor, but for high-resolution graphics the software only supports certain video cards. Gary Becker produced the CoCo3FPGA for Terasic DE FPGA boards. It contains a 6809 CPU core which can run at 25 MHz. It adds 256-color graphics modes, including a 640x450 mode. Roger Taylor developed a CoCo 3 clone, Matchbox Coco, based on the DE0-Nano FPGA board. Renamed to RealCoCo, it has been ported to other FPGA hardware. Clones and cousins The Dragon 32 and 64 are British cousins of the CoCo based on a reference design from Motorola that was produced as an example of the capabilities of the MC6809E CPU when coupled