Intel 4040

The Intel 4040 microprocessor was the successor to the Intel 4004. It was introduced in 1974.

The 4040 was used primarily in games, test, development, and control equipment. The package of the 4040 is more than twice as wide as the 4004 and has 24 pins vs. the 16 of the 4004. The 4040 added 14 instructions, larger stack (8 level), 8 kiB program space, 8 more registers, and interrupt abilities (including shadows of the first 8 registers).

The 4040 family is also referred to as the MCS-40.

New features

• Interrupt
• Single Step

Extensions

• Instruction Set expanded to 60 instructions
• Program memory expanded to 8 KiB
• Registers expanded to 24
• Subroutine stack expanded to 7 levels deep

New support chips

• 4201 - Clock Generator 500 to 740 kHz using 4 to 5.185 MHz crystals
• 4308 - 1 KiB ROM
• 4207 - General Purpose byte Output port
• 4209 - General Purpose byte Input port
• 4211 - General Purpose byte I/O port
• 4289 - Standard Memory Interface (replaces 4008/4009)
• 4702 - 256 byte UVEPROM
• 4316 - 2 KiB ROM
• 4101 - 256 4-bit word RAM