A Short History of the PC - PowerPoint PPT Presentation

A Short History of the PC

• Before the IBM, there were many PC vendors.
• These were typically garage-shop start-ups with shaky financing.
• The big names were Radio Shack and Apple.
• Early personal computers were crude.
• CPUs were 8-bit, usually and 8080 or Z80.
• Storage was usually on audio cassette tape as diskette drives were expensive.
• Monitors were TV sets with a maximum of 64 characters per line.
• Printers were very expensive and often were upper-case only.
• The big applications were WordStar and VisiCalc.

• CPU – Intel 8088
• 16-bit CPU, 8-bit I/O, 4.77 MHz clock
• 8-bit Industry Standard Architecture (ISA) expansion bus.
• 16 K to 64 K RAM (up to 640 K with a RAM expansion card)
• ROM BASIC
• Operating systems
• PC-DOS ($40)
• CP/M ($450)
• UCSD p-System ($550)
• $1265 (plus monitor, video controller, operating system, serial port, floppy disk, and printer)

• Displays
• “High-resolution” character-only (80 per line) with a monochrome monitor.
• Low-resolution graphics controller with a color display.
• RAM cards were needed to expand memory beyond 64K.
• Diskette drives held of 360 Kbytes.
• Modems had speeds of 100 to 300 bps.
• Printers used matrix-impact technology and ribbons.

• IBM published its hardware interface specifications.
• This allowed other companies to develop expansion cards, keyboards, mice, etc.
• IBM decided that they would profit only from the hardware.
• All software was developed by other companies.
• IBM published its BIOS specifications.
• As a result other companies reversed-engineered the BIOS, which allowed PC clones into the market.
• IBM allowed Microsoft to sell DOS to others.

• The basic operating-system commands were in ROM so you could swap your program diskette with one containing data.
• DOS contained few services. For example, an editor had to know how to control your printer.
• Users had to configure peripherals (e.g., modems, ports, and printers) by editing control files, such as autoexec.bat and config.sys.
• The simple software of the day easily fit on a360-K diskette.

• CPU – Intel 8088
• 16-bit processor, 8-bit I/O
• 4.77 MHz clock
• 8-bit ISA bus
• 256 K or 640 K RAM in 36 DIP sockets
• 360K, 5-¼” diskette (720K, 3-½” optional)
• 10 or 20 Mbyte hard disk
• $5000 (with a 10-MB disk)
• Other manufacturers began to enter the PC market.

• CPU – Intel 80286
• 16-bit processor, 16-bit I/O
• 6 or 8 MHz clock
• 16-bit ISA bus
• 512 K on motherboard, 16M maximum
• 1.2M, 5-¼” diskette (1.44M, 3-½” optional)
• 20 or 30 Mbyte hard disk
• EGA graphics
• $6000 with a 20 Mbyte disk

• 1982 – Compaq “Portable” (28 lbs., ac power)
• 1984 – HP introduces the laser printer.
• 1985 – 2400 bps modems become common; the 16-MHz 80386 appears.
• 1986 – Compaq releases the first 80386 PC.
• 1987 – VGA graphics (640480) appear.
• 1990 – Intel introduces the 80486 with an integrated co-processor.
• 1993 – The Intel Pentium debuts at 60 MHz; the PCI bus appears.

• 1981 - DOS 1 (purchased from Seattle Computing for $50,000)
• 1983 – DOS 2 (subdirectory and 10-MB hard disk support)
• 1984 – DOS 3 (1.2-MB diskette and 32-MB hard disk support)
• 1988 – DOS 4 (too buggy to be popular)
• 1991 – DOS 5 (allowed the use of 640-1024K RAM and larger disks, added a disk cache and undelete)
• 1993 – DOS 6 (disk compression and defragging, better memory management)

• 1985 – Windows 1.0 (a DOS shell, crude and slow)
• 1987 – Windows 2.0 (icons, overlapping windows)
• 1990 – Windows 3.0 (16 colors, new file manager, the first successful version)
• 1992 – Windows 3.1 (drag-and-drop, better integration)
• 1995 – Windows 95 (long filenames, dial-up networking)
• 1998 – Windows 98 (USB support, Internet Explorer 4 built- in)
• 2001 – Windows XP (32-bit architecture, DOS independence)