• Memory Organization: 256K × 1 Bit
• Total Capacity: 262,144 Bits (256 Kbit)
• Device Type: Page Mode DRAM
• Package Options: DIP, ZIP (PSZ), and other package variants

Memory Characteristics

• Organization: 256K × 1 bit
• Technology: NMOS DRAM
• Page Mode Operation
• Dynamic Memory (requires refresh)
• Multiplexed Address Bus

Speed Grade

• -12 Suffix
  • Access Time: 120 ns maximum
  • Faster than the -15 version and slower than the -10 version

Electrical Characteristics

• Supply Voltage (VCC):
  • 5 V nominal
  • 4.5 V to 5.5 V operating range
• TTL-Compatible Inputs and Outputs
• Three-State Output Buffer

Addressing

• Memory Density: 262,144 bits
• Addressing Method: Multiplexed row/column addressing
• RAS (Row Address Strobe)
• CAS (Column Address Strobe)
• WE (Write Enable) control inputs

Package Information

• MB81256-12P: Plastic DIP
• MB81256-12PSZ: Plastic ZIP (Zig-Zag In-Line Package)
• Through-Hole Mounting

Operating Temperature

• Commercial Range:
  • 0°C to +70°C
• Storage Temperature:
  • Typically -55°C to +125°C

Features

• 256 Kbit memory density
• Page mode access
• 120 ns access time
• 5 V operation
• TTL-compatible interface
• Low-cost DRAM technology
• Suitable for memory expansion applications

Typical Applications

• IBM PC/XT and AT-era memory expansion
• Industrial controllers
• Telecommunications equipment
• Video systems
• Printers
• Embedded computer systems
• Test and measurement equipment

Key Features

• 262,144-bit DRAM
• 256K × 1 organization
• 120 ns access time
• Page mode operation
• 5 V supply
• RAS/CAS multiplexed addressing
• Dynamic refresh required
• Available in DIP and ZIP packages