The IBM PC lineModel name Model # Introduced CPU Features
PC 5150 August 1981 8088 Floppy disk or cassette system
XT 5160 March 1983 8088 First IBM PC to come with an
internal hard drive as standard.
Portable 5155 February 1984 8088 Floppy-based portable
AT 5170 August 1984 80286 Faster Processor, Faster System
Bus (6Mhz, later 8Mhz, vs
4.77Mhz ), Jumperless
Configuration, Real Time Clock
3270 AT 5281 June 1985 80286 With 3270 terminal emulation
Convertible 5140 April 1986 8088 Microfloppy laptop portable
System Unit
Size: - Width - 20", Depth - 16", Height - 5.5"
Weight: - Without diskette drive - 21 lbs.
- With one - 25 lbs.
- With two drives - 28 lbs.
Electrical: - 120 v. AC
Cycle Time: - Main storage - 410 nanoseconds
- Access - 250 nanoseconds
Memory: - 40K built-in read only memory (ROM)
- 16K to 256K user memory
Standard: - Keyboard for data and text entry
- Cassette player jack for cassette attachment
- Five expansion slots for additional memory anddisplay,
printer, communications and game adaptors
- Built-in speaker for musical programming
- Power-on automatic self-test of system components
- BASIC language interpreter, 16K memory
Keyboard
Size: - Width - 20", Depth - 8", Height - 2"
Weight: - 6 lbs.
Keys: -83 full-function for data and text entry: includes 10 for
numeric entry and cursor control and 10 special function for
scrolling, editing, etc.
-Easy access to 256 characters (ASCII and Special)
Keyboard: -Adjustable typing angle
-Detached from system unit and connected by six-foot cable for
flexibility
-All keys automatically repeat
Diskette drive
Number of diskettes: - Up to two 5¼" diskette
drives
Storage capacity: - 160 kilobytes per
diskette
Diskette
drive
The Intel 8088 microprocessor was a variant of the Intel 8086 and was introduced on July 1, 1979. It had an 8-bitexternal data bus instead of the 16-bit bus of the 8086. The 16-bit registers and the one megabyte address range were unchanged, however.
from wikipedia
Because the 8088 chip is mature and economical, and IBM already had a history of using Intel chips in its products and had also acquired the rights to manufacture the 8086 family. IBM chose it as the first real sense of PC CPU.
Produced From 1979 to 1990s
Common Intel, AMD, NEC, Fujitsu
Manufacture Harris(Intersil), OKI, Siemens, AG Texas Instruments, Mitsubishi
CPU clock rate 4.77 MHZ
Max. CPU clock rate
5 MHz to 10 MHz
Address Bus 20 bit
Main Memory 1 M
Instruction set x86-16
Package(s) 40-pin DIP, 44-pin PLCC
8088 CPU internal use two independent function components, BIU(Bus Interface Unit) and EU(Execution Unit) respectively.
BIU EU
PerformanceDepending on the clock frequency, the number of memory wait states, as well as on the characteristics of the particular application program, the average performance for the Intel 8088 ranged from approximately 0.33-1 million instructions per second. Meanwhile, the mov reg, reg and ALU reg, reg instructions taking two and three cycles respectively yielded an absolute peak performance of between 1/3 and 1/2 MIPS per MHz, that is, somewhere in the range 3–5 MIPS at 10 MHz.
The descendants of the 8088 include the 80188, 80186, 80286, 80386, and later software compatible processors, which are in use today. See below for a more complete list.
Cassette tape
• SAM(Sequential Access Memory)
German-made cassettes sold for
computer data recording, circa
1980
Floppy diskettes
in IBM PC
• one or two 5.25-inch floppy disk drives
• single-sided double-density drives
(SS/DD, a.k.a. SSDD), or double-sided
double-density drives (DS/DD, a.k.a.
DSDD)
Floppy diskettes
• magnetic storage
• DAM(Direct Access Memory)
• floppy disk drive
• 3.5-inch (89 mm), 5.25-inch (133 mm) and 8-inch (200 mm)
• The disks were dubbed "floppy" because the diskette packaging was a very flexible plastic envelope
DAM(direct access memory/storage)
• A floppy disk, like a cassette tape, is made from a thin piece of plastic coated with a magnetic material on both sides. However, it is shaped like a disk rather than a long thin ribbon. The tracks are arranged in concentric rings so that the software can jump from "file 1" to "file 19" without having to fast forward through files 2-18. The diskette spins like a record and the heads move to the correct track, providing what is known as direct access storage.
Capacity of the floppy disk
As to floppy disks in IBM PC:
•512 bytes per sector
•8 or 9 sectors per track
•40 tracks per side
•single-side or double-side
The capacity of IBM PC is 160kB or 320kB
or 180kB or 360kB
Floppy diskettes
in IBM PC
• one or two 5.25-inch floppy disk drives
• single-sided double-density drives
(SS/DD, a.k.a. SSDD), or double-sided
double-density drives (DS/DD, a.k.a.
DSDD)
Single density and double density
• single density and double density indicated a
difference in logical encoding
• FM(frequency modulation)
• MFM(Modified Frequency Modulation)