Memory Capacity Expansion: Techniques and Circuits

Memory capacity expansion is a crucial aspect in the field of computing and data processing. It allows for increased storage capabilities to meet the growing demands of modern applications.

One common method of memory capacity expansion is by connecting multiple memory chips. As mentioned, for DRAM megabit memory, three memory chips can be connected in parallel, one on top of the other. This connection is achieved using additional wires, such as the 21st and 22nd pins for a 1 Mbit device or the 27th and 28th pins for a 64 Mbit device. The chips are then accommodated within a device package.

Another approach involves the use of circuit cards. In a preferred embodiment, a data processing system can have up to two circuit cards, each of which can have multiple banks of memory. Each circuit card includes signal generating circuitry that generates electrical signals representing the amount of memory on the card. Additionally, combining circuitry on the circuit card combines the coded signals from multiple cards to indicate the total memory and its addressable location.

In the context of random access memory (RAM), different types like SRAMs and DRAMs have their characteristics. SRAMs offer faster data read/write speeds, while DRAMs can store more data for a given physical size and cost due to their simpler cell structure.

Capacity Expansion is not only about hardware components but also involves software aspects. In certain operating systems like Microsoft's Windows NT, 2000, or Novell's NetWare 4.2, 5, it is possible to increase the volume capacity online.

In conclusion, memory capacity expansion is a complex yet essential area that requires a combination of appropriate hardware designs and software support to effectively enhance the storage capabilities of systems.