The Intel 8080 microprocessor was the predecessor of the 8085 or the Z-80 microprocessors. It was designed and manufactured by Intel. This Microprocessor was released on April 1974. It was an 8-bit Microprocessor.
The Intel 8085 is also an 8-bit Microprocessor, which was introduced in 1976. It is very close to the 8080 microprocessor, but some slight changes and modifications are present. The Zilog Z-80 was also introduced in 1976. Basically, the Intel team was divided and formed a new Group called Zilog. The Zilog team was introduced the Z-80 Microprocessor.
In this diagram, we can see that the 8080 Microprocessor takes two additional chips 8224 and 8228 for the Clock generation and system controlling respectively. The 8224 clock chip provides a two-phase clock for the 8080 Microprocessor.
This chip has Single Interrupt pin INT. Here 8-bit data buses and 16-bit address buses are present. There are 244 instructions present for the Microprocessor 8080.
Here is a diagram of 8085 Microprocessor. This does not need the 8224 and 8228 chips with it. These are combined and placed inside the chip.
Here 246 instructions are present for 8085. The RIM and SIM instructions are added to this model. Here serial communications are present and also 8085 is much faster than the 8080.
Now let us summarize the important points of 8080 and 8085 Microprocessors.
|8080 Microprocessor||8085 Microprocessor|
|8 dedicated pins are there as Data bus (D0 to D7)||Multiplexed 8 bit data pins are present for data bus (AD0 to AD7)|
|16 address pins are present (A0 to A15)||8 pins Higher order Address bus (A8 to A15) and 8 multiplexed address bus (AD0 to AD7), and the Address Latch Enable (ALE) pins are present.|
|The power supply voltage is +5, -5 and +12 volts||The power supply is only +5 volts.|
|Single Interrupt pins are there (INT)||With INT, there are four more interrupt pins (TRAP, RST7.5, RST6.5, RST5.5)|
|Serial Communication facility is not present||The Serial Communication facility is present with SID, SOD Pins and RIM, SIM instructions|
|Additional chips for Clock and system controlling is needed||No additional chips are needed for clock and system controlling tasks.|