Exam cram notes:
1. Some important acronyms:
ISA is an acronym for Industry Standard
EISA is a acronym for Extended Industry
PCI is an acronym for Peripheral
Component Interconnect, and
MCA stands for Micro Channel
CPU stands for Central Processing Unit.
SCSI stands for Small Computers Systems
Interface. It is pronounced as Skuzzy.
DIMM stands for Dual-Inline Memory
SIMM stands for Single-Inline Memory
SRAM - Static random access memory -
Uses transistors to store information
DRAM - Dynamic random access memory -
Need to be refreshed to retain data.
ROM - Read only memory - Data in ROM can
not be erased or changed
PROM - Programmable ROM - Once
programmed, data can't be erased or
EPROM - Erasable PROM - Data can be
erased by ultraviolet light and can be
reprogrammed using a programmer.
EEPROM - Electronically erasable PROM -
Data can be erased electrically. Chip
can then be reprogrammed. EEPROMs are
frequently used to store BIOS.
2. RAM stands for Random Access Memory.
There are basically two types of RAM:
DRAM - Dynamic RAM, and
SRAM - Static RAM.
SRAM, being expensive, usually used for
Cache memory. DRAM, being cheaper, is used
for main memory.
3. PC Memory cards:
A SIMM has a single row
of 72 contact fingers, each making contact
on both sides (Same pin number present on
both sides of the card). An older version of
SIMM card contain 30pins, and were used in
386 and some 486 machines.
A DIMM (Dual-Inline Memory Module)has two
rows of connecting fingers, one row on each
side, and the total number of contacts are
4. Monitor Connectors:
If you are using a Monochrome / CGA/ EGA
monitor, it is a digital monitor and will
have a DB-9 Male connector that plugs
into a digital adapter.
If you are using a VGA/ SVGA monitor,
it will have a male DB-15 connector
that plugs into an analog adapter. You
should never interchange an analog monitor
to that of a digital adapter and vice versa,
or severe damage may take place.
5. The storage capacity of various types of
5 1/4" ---DSHD----1.2MB
3 1/2" ---DSDD----720KB
3 1/2" ---DSHD----1.44MB
3 1/2" ---DSED----2.88MB
DSDD: Double Sided Double
DSHD: Double Sided High
DSED: Double Sided Extra
6. Processor package types:
8088, 8086 processors used 40 pin DIPs.
80286,80386, 80486, and some Pentium
computers (60MHz, 66MHz) used PGA (Pin Grid
Pentium chips (75 MHz and above) used SPGA
(Staggered PGA). Pentium II CPUs use
catridge type mounting method, called
7. Video types:
The table below compares
various video types:
Max. Color depth
16 Million Colors
1280X1024 or even
8. When you are changing a video monitor on
a PC (say, during troubleshooting):
When you are installing a
different SVGA monitor, it is likely that
the new monitor has the same capabilities as
the old one. As a result, the image on the
screen may not be readable. In such
instances, change the video resolution to
Standard VGA before installing the new
monitor. You can change the resolution
appropriately after the image on the screen
is readable with the new monitor. It may
also be necessary to load appropriate device
driver, if you are installing a different
9. FAT file system:
Under FAT file system, the
maximum size of a cluster is 32 KB and the
maximum number of clusters is 65536.
Therefore, the maximum size of a partitions
is the number of clusters multiplied by the
max size of the cluster, which is equivalent
to 2 GB. Remember that 1 KB = 1024 bytes.
10. Real Time Clock:
The Complementary Metal-Oxide
Semiconductor (CMOS) allows the computer to
store the Real Time Clock (RTC)and other
device information even after the computer
is switched off and on. This is achieved by
using a battery back, just for CMOS.