240722-02 485Turbocache Module 199011

This document is a preliminary product specification for the Intel 485 Turbocache Module, a performance upgrade for 25 MHz or 33 MHz i486™ Microprocessor systems.

Key features and benefits:

• Performance Upgrade: Provides a 5-30% (15% average) performance boost by adding external cache memory.
• High Performance Cache: Offers zero-waitstate access and one-clock bursting, utilizing a 2-way set-associative design with 16-byte line sizes. It supports BIOS ROM caching.
• Capacity Options: Available in 64KB (82485MA) and 128KB (82485MB) configurations in a single 113-pin module.
• Scalability: Multiple modules can be cascaded to achieve larger cache sizes, up to 512KB.
• High Integration: Integrates the tag, data, parity, and controller into a compact 7-square-inch area, leveraging the Intel 82485 cache controller.
• Ease of Use: Designed for simple, end-user/dealer installation. It is software-transparent, requires no jumpers, configuration software, or BIOS/operating system support, and maintains full compatibility with i486 CPU bus timings and invalidation mechanisms.
• Data Integrity: Monitors cache data integrity using a parity bit per byte.
• Write Policy: Operates as a write-through cache.

The document details the module's functional description, system interface signals, various system configurations (single or multiple caches), operational and performance considerations, and mechanical/electrical specifications.