home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: aus.computers.ibm-pc
- Path: sparky!uunet!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!spool.mu.edu!umn.edu!math.fu-berlin.de!fauern!LRZnews!regent!monu1.cc.monash.edu.au!monu6!bruce.cs.monash.edu.au!munnari.oz.au!metro!dmssyd.syd.dms.CSIRO.AU!stuarta
- From: stuarta@syd.dms.CSIRO.AU (Stuart Andrews)
- Subject: IBM-PC Tute
- Message-ID: <BxunK7.J5q@syd.dms.CSIRO.AU>
- Keywords: Lesson 1
- Sender: news@syd.dms.CSIRO.AU
- Organization: CSIRO Div. Maths & Stats, CSIRO Div. Applied Physics
- Distribution: aus
- Date: Tue, 17 Nov 1992 07:31:18 GMT
- Lines: 109
-
- How to make your own IBM Compatible Personal Computer.
- ------------------------------------------------------
- Lesson 1. The computer Motherboard.
-
-
- |Connector for
- |power supply
- v
- ------------------------------------
- | ooooo |
- | |
- | |
- |] <-Keyboard connector |
- | |
- | === <- co-processor
- | ========= === |
- | ---<-processor |
- | ========= | | |
- | --- |
- | ========= ==== |
- | |
- | ========= |
- | |
- | ========= ==== |
- | |
- | ========= ==== [] = = = = |
- | [] = = = = |
- | ========= ==== [] = = = = |
- | [] = = = = | <- Memory (RAM)
- | ========= ==== [] = = = = | Usually a couple
- | [] = = = = | of dozen.
- | ========= ==== [] = = = = |
- | [] = = = = |
- | |
- ------------------------------------
-
- ^ ^
- | Memory (ROM)
- Expansion bus May be from 1 to eight
- slots
- ---------------------------------------------------
-
- MEMORY (RAM) Rows of small chips. Usually 4,6,or 8 rows of 8 or 9
- chips. Markings usually include something like 41256 or 41128 or
- 41512 (a number that is a multiple of 2 (2,4,8,16,32,64,128 etc)
- They hold the computers working memory while it is switched ON
- but lose everything when off. Sometimes there is space to
- add more chips. In more modern motherboards, RAM will be fitted in
- the form of several plug-in modules (SIMMs or SIPs) which are
- small printed circuit board which stand up on the motherboard.
-
- MEMORY (ROM) One or more chips (maybe with a glass window) maybe
- marked 27128, 27256, 27512 etc or if it has a sticker, the
- word "BIOS" or something like. A big chip (about 2 x 5 cm),
- this/they hold the computer's basic startup program. ROMs
- do not lose their memory when turned off so this is the first
- place the computer looks for what to do when turned on.
-
- POWER SUPPLY CONNECTOR. A row of about 8 or 10 pins to connect
- by a cable to the power supply. The p.s. is a big silver box
- with a fan in it, a switch and connects to the power point.
-
- PROCESSOR: Usually a square black chip. Marked
- "i80286-16" the 80286 is the type of processor,
- the -16 is the speed limit for the chip in megahertz (MHz) Also
- available, i8086 and i8088 (old types), i80386 (pretty good),
- i80486 (the best). Usually referred to by the last three numbers,
- ie; 286, 386, 486.
-
- CO-PROCESSOR: In the case of '286, the co-processor is a 40 pin DIP
- (long, thin). For 386 and 486, it is a square chip. Part numbers are
- i80287, i80387 and i80487. What do they do? They add the capability of
- doing floating point calculations to the computer. Usually, they can be
- done in s/w without the chip, but this way is much faster. Some
- programs *require* the chip, others will work around it, some s/w
- doesn't need it at all - check the individual s/w. Also called
- Math-co-processor, a more correct name.
-
- EXPANSION BUS: Used to plug in all new stuff like disk drive
- controllers, video (monitor) cards, mouse cards, joystick cards
- All jobs except for the basic computer are done by add on cards
- which all look quite similar, are the same shape, but have different
- electronics depending on what they do. More on these in Lesson 2.
-
- KEYBOARD CONNECTOR: Where you plug the cigarette lighter. What do
- you reckon it does?
-
- All of the above bits usually com already attached to the computer
- motherboard. (Although you often have to buy RAM and plug it in
- yourself (if making your own)) and none of these bits are left out.
- They may be re-arranged in different places. (except the Expansion
- bus and the Keyboard connector and the power supply connector)
-
-
- End of lesson 1. Next Lesson. Expansion cards. How to make the computer
- talk to the outside world.
-
-
-
-
- --
- "Two to the power of one hundred thousand to one against.
- That's pretty improbable you know" (Ford Prefect)
-
- "I do not agree with what you say, but I will fight to the death
- for your right to say it" (Voltaire)
- ################################################################################
- Stuart Andrews (stuarta@syd.dms.csiro.au)
- Opinions posted here are mine and do not necessarily comply with those of CSIRO
-