SILICON GATE MOS 8255

 

IP~

LSB

 

 

 

 

 

 

 

PAl

 

 

 

I

PA2

 

 

 

PA3

 

 

MODE 0

JPA4

f ----------- ..

 

 

PAS

 

 

(OUTPUT)

;

PA6

12-BIT

---.

 

 

PA7

D-A

 

 

PC4

CONVERTER

 

 

 

(DAC)

 

 

 

PCS

 

 

8255

 

PC6

 

 

'-PC7

MSB

 

 

 

 

,PCO

STB DATA

 

 

 

 

 

 

 

PC,

OUTPUT EN

 

BIT

I

 

 

 

SET/RESETl PC2

SAMPLE EN

 

 

 

PC3

STB

 

 

,...-

 

 

 

 

 

PBO

LSB

 

 

 

PB,

8-BIT

 

 

 

A-D

 

 

 

PB2

..--

 

 

CONVERTER

MODE 0

 

PB3

(ADC)

 

-

 

 

(INPUT)

 

PB4

 

 

 

 

PBS

 

 

 

 

PB6

 

 

 

 

P~

MSB

 

INTERRUPT

REQUESTi

PC3

r --

 

 

PBO

Do

 

 

PB,

0,

 

 

PB2

O2

 

 

PB3

0 3

FLOPPY DISK

 

PB4 .

. 0 4

CONTROLLER

 

AND DRIVE

 

PBs

DS

 

MODE 2-

PB6

0 6

 

ANALOG OUTPUT

PB7

0 7

 

 

 

 

PC4

DATA

STB

 

PCS

ACK (IN)

 

PC7

DATA READY

 

_Pe6

ACK (OUT)

8255

 

 

 

 

PC2

TRACK "0" SENSOR

 

PCo

SYNC READY

 

PC,

INDEX

 

 

r -

 

 

 

PAO

ENGAGE HEAD

 

PAl

FORWARD/REV.

ANALOG INPUT

P~

READ ENABLE

MODE 0 _

P~

WRITE ENABLE

(OUTPUT)

PA4

DISC SELECT

 

PAs

ENABLE CRC

 

PAG

TEST

 

 

_PA7

BUSY LT

Digital to Analog, Analog to Digital

Basic Floppy Disc Interface

INTERRUPT

INTERRUPT

REQUEST I

REQUEST i

PC3 ""-PAo~------t~....Ro-------------.--.

 

PAl

R,

CRT CONTROLLER

 

PA2

R2

•

CHARACTER GEN.

 

PA3

R3

•

REFRESH BUFFER

 

PA4

R4

•

CURSOR CONTROL

 

 

 

 

PAs

RS

 

 

MODE 1

PA6

SHIFT

 

 

(OUTPUT) -

PA7

CONTROL

 

 

PC 7 I-------t~.DATA READY

PC 6ACK

PC3

PAo ....----- 1 R

 

 

 

O

 

 

PAl

R,

 

 

PA2

R2

8 LEVEL

 

PAPER

 

PA3

R3

 

TAPE

 

PA4

R4

READER

 

 

MODE 1

PAs

Rs

 

(INPUT) -

PAG

RG

 

 

PA7

R7

 

 

PC4

....----.... STB

 

 

PCs

ACK

 

8255 L.-

PCSBLANKED

PC4BLACK/WHITE

L.-

PCG

....

...

 

STOP/GO

 

8255

 

MACHINE TOOL

 

 

 

PCo

START/STOP

 

-PC2 I--------li~. ROW STB

PC,

COLUMN STB

PCO

CURSOR HN STB

MODE 0

PC

.....----- 1 LIMIT SENSOR (H/V)

(INPUT)

1

 

{

PC2

....----- IOUTOF FLUID

 

PBO I--------t~. l

 

 

 

IPB

 

 

CHANGE TOOL

MODE 0 _

PB,

!

 

 

 

I PB:

1--------t~.LEFT/RIGHT

(OUTPUT)

PB2

i

CURSOR/ROW/COLUMN

 

 

J

PB2

 

UP/DOWN

 

PB3

1

 

MODE 0

PB

3

 

HOR. STEP STROBE

 

1

 

 

 

 

:--ADDRESS

 

 

 

 

 

 

PB4

!

H & V

(OUTPUT) lPB4

 

VERT. STEP STROBE

 

PBs

I

 

 

 

 

PBs

 

SLEW/STEP

 

 

 

 

 

 

 

 

 

.....----

PB6

J

 

.....

 

.......

PBG

 

FLUID ENABLE

..

.._------------~

 

 

7..

1._-----------_...

 

,-P~

 

 

 

 

 

PB

 

 

EMERGENCY STOP

Basic CRT Controller Interface

 

Machine Tool Controller Interface

5-128

Page 195 Page 197
Page 196
Image 196
Intel 8080 manual Pco, ~.Left/Right
Page 195 Page 197

8080 specifications

The Intel 8085 and 8080 microprocessors were groundbreaking innovations in the world of computing, paving the way for future microprocessor development and personal computing.

The Intel 8080, introduced in 1974, was an 8-bit microprocessor that played a fundamental role in the early days of personal computing. With a 16-bit address bus, it had the capability to address 64 KB of memory. Running at clock speeds of 2 MHz, the 8080 was notable for its instruction set, which included 78 instructions and 246 opcodes. It supported a range of addressing modes including direct, indirect, and register addressing. The 8080 was compatible with a variety of peripherals and played a crucial role in the development of many early computers.

The microprocessor's architecture was based on a simple and efficient design, making it accessible for hobbyists and engineers alike. It included an 8-bit accumulator, which allowed for data manipulation and storage during processing. Additionally, the 8080 featured registers like the program counter and stack pointer, which facilitated program flow control and data management. Its ability to handle interrupts also made it suitable for multitasking applications.

The Intel 8085, introduced in 1976, was an enhancement of the 8080 microprocessor. It maintained a similar architecture but included several key improvements. Notably, the 8085 had a built-in clock oscillator, simplifying system design by eliminating the need for external clock circuitry. It also featured a 5-bit control signal for status line management, which allowed for more flexible interfacing with peripheral devices. The 8085 was capable of running at speeds of up to 3 MHz and had an extended instruction set with 74 instructions.

One of the standout features of the 8085 was its support for 5 extra instructions for stack manipulation and I/O operations, which optimized the programming process. Additionally, it supported serial communication, making it suitable for interfacing with external devices. Its 16-bit address bus retained the 64 KB memory addressing capability of its predecessor.

Both the 8080 and 8085 microprocessors laid the groundwork for more advanced microprocessors in the years that followed. They demonstrated the potential of integrated circuits in computing and influenced the design and architecture of subsequent Intel microprocessors. Their legacy endures in the way they revolutionized computing, making technology accessible to a broader audience, and their influence is still felt in the design and architecture of modern microprocessors today.
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