On 12th August 1981 IBM introduced Personal Computer

On August 12, 1981, at a press conference at the Waldorf Astoria ballroom in New York City, Estridge
IBM presented its
IBM Personal Computer (IBM PC)
with a price tag of $1,565.
IBM Personal Computer (PC), also known as IBM Model 5150, equipped with 4,77 MHz Intel 8088 microprocessor and with Microsoft MS-DOS operating system. Deliveries started the following month.
In the first year, 200.000. were sold. For comparison, Sinclair ZX 80, very popular and cheap, sold just 70.000 pieces in one year.

For the $1,565 price one got a system unit and a keyboard. Unit containing only 40K of ROM (read-only memory) and 16K RAM of user memory, built-in speaker for tone generation (today some would say music).
Most important it offered five expansion slots for expanded memory, display and printer ports, game paddles.

Keyboard contained 83 keys and was connected to the unit by a coiled cable, so one could move keyboard , but added also numeric keypad and several special keys for writing and editing text.
Extra options that were available were color display, a printer, two floppy drives, extra ram, serial and game adapter and software packages, like text processing.

Most important options were:

  • Printer could print 80 characters per second in two directions with  12 different character styles.
  • Color onitor had 16 foreground and background colors and 256 characters for text applications. Its graphics were in four colors.
  • Expansion ram card could be plugged into the option slots to increase ram to 256K.

But the new IBM PC could hook up to the home TV set and you could play “some” games.

In 1983 Compaq Computer Corporation will release the first compatibility clone of the IBM PC, but with its own BIOS.
Compaq incorporate an identical copy of PC architecture, since IBM architecture was quite open and IBM PC was made using (′′ assembling ′′) products available (off shelves components)  on the market.

link:IBM PC 5150 with 64Kb RAM and Monochrome Display simulation
link:Birth of IBM PC