To: The Prophet who wrote (72720 ) 5/13/2001 3:40:22 PM From: pheilman_ Read Replies (1) | Respond to of 93625 Prophet, re: Uh, of course they don't admit that they infringe - where is the alleged comment about "protecting Sega?" Let me answer this from hard-won knowledge. Hitachi makes a line of embedded RISC microcontrollers, SuperH. Their biggest customer was Sega. The Sega Saturn used 2 SH-2s and an SH-1. The meagre success of the Saturn was enough to propel the SuperH family to the top of the sales rank for 32 bit embedded processors (briefly). The Saturn was great for 2D and scrolling games, but was difficult to program, and didn't handle a lot of polygons for 3D games. The SH2 had a built-in SDRAM interface and the Saturn may have been the first commercial use of SDRAM. As sales dried up for the Saturn against the Sony Playstation, Hitachi and Sega worked together on a new processor specifically to support 3D gaming. This became the SH4. Sega provided the code needed to draw the triangles and Hitachi made sure that the SH4 could execute that particular code fast. Floating point opcodes were added for all of the specific tasks for drawing triangles: dot product for finding whether triangle was facing viewpoint, 4x4 matrix times 4x1 vector to project vertex onto view. The processor was also given a 64-bit wide 100 MHz SDRAM interface. The triangle calculation was tuned to ensure that an integer and a floating point opcode were being dispatched on every clock. During simulations of the Dreamcast it became clear that latency was very critical as the core would have to wait 10s of cycles every time there was a cache miss. (and this is only at a 200 MHz core frequency with a synchronous bus interface). (Latency is even more important for faster cores running "normal" code. By normal I mean anything but 3D games.) The Dreamcast launched in 1999. Rambus, the little weasels, came along and threatened to restrict the import of SH4s and Dreamcasts as the SDRAM interface "infringed" on their patents. Hitachi rolled over for Rambus and signed to pay royalties as they were pressured by Sega to keep the Dreamcast available in the US. Now that the patents have been shown not to read on SDRAM interfaces I suspect that Hitachi will quickly stop paying royalties to Rambus. Subsequently, PSX2 killed the Dreamcast. But sales aren't that good for the PSX2 yet, either. A bit of karma in all this. Hitachi had previously been in battle with Motorola over Hitachi's CMOS version of the 68000 line. Motorala was upset that Hitachi's parts were faster and ended the second source agreement. Hitachi responded by asking for restrictions on the import of 68040s used in Mac Quadras. Due to the battle Hitachi needed to come up with a completely different 32-bit processor family. And believe me, the SuperH is a completely different processor.