dbraun@cadev4.intel.com (Doug Braun ~) (12/15/87)
People have asked me what the Z-280 is, so here is a description: The Z-280 is a new Z-80 compatible chip from Zilog. It includes: Enhanced instructions including 16-bit signed and unsigned multiply and divide. Many new addressing modes for most instructions, including 16-bit indexed, stack pointer relative, pc relative, and base-indexed. On-chip peripherals: One serial port, 4-DMAs, 3 counter timers. Paged memory management, supporting virtual memory and seperated code and data space. User and system modes, allowing 'illegal opcode' traps for things like I/O in user mode. A 256-byte cache. Configurable for a 16-bit bus interface with to do burst reads (4 words in one bus cycle). This is a very sophisticated chip. With a 16-bit bus and burst memory, you shopuld get about 5x speedup, as far as I can tell. With an inproved compiler for the new instructions, even more speedup will result. The chip has been available for several months; single unit price is about $40. It blows away the Hitachi HD61480 chip, which is also a Z-80 enhancement. That chip has virtually no added instructions, no new addressing modes, crude memory management, no protection, and the same old Z-80 bus interface. By the way, the Z-280 will also run with the standard Z-80 bus, as well as the 16-bit bus. Doug Braun Intel Corp CAD 408 496-5939 / decwrl \ | hplabs | -| oliveb |- !intelca!mipos3!cadev4!dbraun | amd | \ qantel / Doug Braun Intel Corp CAD 408 496-5939 / decwrl \ | hplabs | -| oliveb |- !intelca!mipos3!cadev4!dbraun | amd | \ qantel /