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BUILD AN AT-COlVIPXI'IHLE COlVIP R There's never been a better time to build your own IBM AT-compatible computer. Dick Smith Electronics now have a deluxe kit available with lots of options. By GREG SWAIN The DSE AT-compatible with Wordstar up and running on the screen. The monitor is Multitech's high resolution model. 50 SILICON CHIP A lot has happened to the PCcompatible market in the last few years. Take a look in just about any electronics or computer magazine these days and you'll see adverts for all sorts of computer hardware, a lot of it of Taiwanese manufacture and at prices undreamt of a few years ago. In addition to buying readyassembled hardware, you can now also buy literally dozens of PCcompatible motherboards and a host of plug-ins and peripherals ranging from floppy disc and hard disc drives to controller cards, power supplies, enhanced graphics adapter cards, and input/output (1/0) cards. The AT-compatible described in this article was assembled from boards and other hardware supplied by Dick Smith Electronics. As you'll see , the machine goes together quickly and easily at a very competitive price. Why should you assemble your own computer instead of buying a complete unit? There are several good reasons. First, you will learn a lot about computer hardware and how the computer is configured. Second, you can build the computer to match your requirements and your budget. And third, you will know how to expand and upgrade your system if the need arises later on. But perhaps the main incentive for assembling your own PC/AT { J "...,;., / t t J I. i J_ _f i l I l I I l I i ./ ! I l I J I . !' f' ! l l lI /I ! r r r r I ! l JI ! I I~ ( iillLU Everything you need to assemble an AT-compatible computer system. Clockwise from top: keyboard, case (with hinged lid), hard/floppy disc controller card, EGA card, 1/0 card, 20Mb hard disc drive, 1.2Mb floppy disc drive, power supply, motherboard (centre). compatible computer is that you can save lots of dollars. And by buying from a large organisation like Dick Smith Electronics, you can rest easy in the knowledge that if you get into trouble or need service in the future, it will be available. To get an idea of the ease of assembly of such a system, we decided to have a look at the system now being marketed by Dick Smith Electronics. We found the whole process an interesting one and on the whole quite straightforward although there were a number of hurdles to jump over before the unit would burst into song. Having read our account, any aspiring builder is sure to find the going much easier. The parts needed Before starting assembly, you have to decide how the computer is to be configured. There are quite a few options. For example, you can choose a minimum system configuration with just one 1.2Mb floppy disc drive, or you can specify two floppies or a mixture of floppy and hard disc drives. After that, you have to decide which disc controller board you require. You can also choose between two keyboards (either an 84-key unit or a 101-key unit) and four different I/O cards. Table 1 lists the various items you need to consider. Finally, there are a few basic items about which you have no choice. These include the motherboard, a 200W switchmode power supply and a case. In this article we '11 describe the assembly process for a system equipped with 512K of on-board RAM, one 1.2MB floppy disc drive. one 20Mb hard disc drive. a hard/floppy disc controller card, an EGA (Enhanced Graphics Adapter) card. and a serial/parallel 1/0 card. And, once the system is assembled, we'll show you how to configure it so that it boots up to the DOS prompt from the hard disc. Note, however, that other systems can be just as easily installed, with only minor variations in the assembly process. It's simply a matter of following the manuals supplied with the hardware. The motherboard The X1000 "Baby" AT Motherboard is literally the heart of the computer and is supplied completely preassembled. It features an 80286 microprocessor and can run at 6, 8, 10 or 12MHz (switch and software selectable). It also has eight 1/0 slots, hardware reset and keyboard lock connectors, a battery-backed CMOS memory to maintain system configuration, a real time clock and calendar. and provision for up to 1024K (1 0ECE/IIHE!l -i987 51 TABLE 1 : PARTS LIST Baby AT Motherboard .... .. ...... ........ .... .... .. ..... .$995 200W Power Supply .... ... .... ..... ..... ... ...... ..... ... $275 The 200W power supply features numerous power connectors for the motherboard and disc drives. megabyte) of on-board RAM. The necessary BIOS ROM chips are also supplied with the motherboard, plugged into the appropriate sockets. BIOS stands for Basic Input/Output System and is used to provide any special 1/0 routines for discs, terminals, printers and so on. Before mounting the motherboard in the case, you first have to install the RAM chips. These are plugged into four rows of nine sockets on the motherboard - Row 0, Row 1, Row 2 and Row 3. A minimum of 256K and a maximum of 1024K may be installed on the motherboard. Be sure to use 120ns (or faster) RAM chips, as slow speed RAM can cause the computer to intermittently lock up (lO0ns is faster, 150ns is slower). Both 64K 4164 chips and 256K 41256 chips can be used, depending on the amount of memory you wish to install. If, you are installing 512K of onboard RAM , you will need 18 41256 RAM chips. These are plugged into rows 0 and 1, with the other two rows left empty. Other system memory configurations are clearly detailed in the assembly manual supplied with the motherboard. Note that the 640K memory size requires a mixture of 256K 41256 chips and 64K 4164 chips. The 41256 devices are plugged into the first two rows (rows 0 and 1), while 52 SILICON CHIP Baby AT Case .... .... .. .. ....... .................... .... .... $175 Disc Controller: Floppy Controller .............. ...... ....... .......... ......$1 2 9 Hard/Floppy Controller .. .... .......... .. .... ... .. .. ... ... $399 Disc Drives: 1 .2Mb Floppy Drive .......... ........ ..... ..... .. ... .. .... $269 20Mb Hard Disc Drive .. ... ............ ... .. ......... ... .. $795 Display Adpater: CGA/Parallel Printer Card ..... ..... ... ..... ............. .$129 MGA/Parallel Printer Card (MGA) ... ..... .... ... ...... $149 EGA Card with Hercules Compatibility ..... ... ....... $399 Serial/Parallel/Game Card .. ......... ...... .... ... ....... $139 Keyboards : 84-Key Type .... .... .. ... ... ...... ..... ...... ... .. .. ........ $129 101 Key-Type with Numeric Keypad ... ....... .... .. $149 Note: on-board RAM for the Motherboard is an extra cost item. the 4164s are plugged into rows 2 and 3. Don't mix 41256s and 4164s on the same row. Leave the ICs in their conductive foam until you are ready to install them in the motherboard. You will find that you will have to bend the leads of the chips in slightly so that they fit the sockets. This can be done by pressing the leads against a flat surface. Try to avoid touching the leads of the ICs, since they are easily destroyed by static electricity. When installing the devices, make sure that the notched end is towards the rear of the motherboard. Next, you will have to set switches S3 and S4 on DIP switch block SWl to match the memory size. In our case, we set S3 to OFF and S4 to ON to correspond to a memory size of 512K. S1 is not used and should remain in the off position. S2 selects the the primary display adapter. Set the switch to OFF to select a Monochrome Display Adapter (MDA), and to ON to select a Colour Graphics Adapter (CGA) or a Professional Graphics Controller (PGC). S2 can be in either position if an Enhanced Graphics Adapter [EGA) is to be installed [unless a second type of display adpter is also installed). The next step is to check jumper JP4 which is adjacent to the BIOS Close up view of switch block SW1 on the motherboard. Be sure to set the switches to match your system. ROMs. This jumper is installed in the factory to suit the BIOS ROMs supplied and should be across pins 2 and 3 (ie, across the two pins nearest the front of the board. Motherboard installation Before installing any of the hardware, you first have to remove the disc cage from the case. To do this, undo the two screws at the top, then slide the cage back until the metal tongues on the bottom are disengaged. The cage can then be removed from the chassis. Next, mount the speaker on the left-hand front of the chassis - it is held in place by the metal tongues. You are now ready to install the motherboard. To do this, first screw the three metal standoffs to the base of the chassis. This done, push the plastic standoffs supplied into the ap- , KEYBOARD SOCKET 7 EXPANSION SLOTS ROM BIOS ___,_____ RAM BANKS ROW 0 Power supply installation The power supply is next. First, remove and set aside the four screws on the back of the supply (the side with the power connectors}. Next, position the supply in the case where the disc cage normally sits, and locate the two sets of wires with the 6-pin connectors. Plug the 6-pin connector with the orange lead into the rear six pins of the power connector (J18) on the motherboard. The other 6-pin connector plugs into the front six pins of the J18 connector. Don't transpose these two connectors you will almost certainly damage the motherboard if you do. With the connectors plugged into the motherboard, the power supply can now be permanently installed in the chassis. It should slide back against the rear panel, with the power switch on the right. Fasten it with the four screws previously removed. EGA and 1/0 cards ROW 1 ROW 2 ROW 3 SP£AJCBI COIIMECTllllll SW1 The XlO00 Baby-AT motherboard comes complete with BIOS ROM installed. Don't forget to remove the cardboard from the backup battery terminal. propriate mounting holes on the motherboard (don't use the holes that match the metal standoffs). Install the motherboard by sliding it from the left of the case until the standoffs engage the matching slots on the base, and secure by installing the screws in the metal standoffs. Finally, connect the leads from the various switches and LEDs on the front panel to the appropriate connectors (JP1, J15 , J21 and J22) on the motherboard. Follow the manual closely here and you cannot go wrong. A point to note here concerning the speed indicator LEDs. As supplied, the machine comes with two orange LEDs and these show the two higher speeds; ie, 10MHz and 12MHz. If you turn it on with the Turbo switch in the Off setting, the machine will boot at 8MHz and both indicator LEDs will be off. You can then change the operating speed while a program is in progress by holding down the Ctrl and Alt keys together and then pressing the "+" key. Doing this repeatedly changes the speed in the following order: 8MHz, 6MHz, 12MHz, 10MHz, 8MHz, 6MHz and so on. If you turn the machine on with the Turbo switch in the On position, it will boot up at 6MHz. Note: some programs will lock up if you attempt to change speeds while they are running and other software which is copy protected will only run at 6MHz. The X2012 1/0 card and the X2013 EGA (enhanced graphics adapter) card are plugged into the expansion slots of the motherboard. But first there are a few things to check. We'll start with the 1/0 card. This offers a variety of 1/0 functions including up to two RS-232C serial interface ports, a Centronics parallel printer port, and a games adapter port. Unless you are using other devices wiih 1/0 ports, the factory default settings on this board are the ones to use. Supplied with 1/0 card is an interface cable for the primary serial port (DB9P to DB25P) and a bracket for the secondary serial port connector and games port connector. The games adapter port is supplied as standard while the secondary serial port connector is optional. Before plugging in the 1/0 card, you should first check the settings of two DIP switches - SW1 and SWZ. The correct settings are clearly illustrated in the manual supplied with the card. It doesn't particularly matter which expansion slot you plug the 1/0 card into (we chose the slot nearest the left-hand side of the case). Use the self-tapping screws DECEMBER1987 53 - PRICED FOR HOME, BUILT FOR WORK! Bargain B & W Monitor 'D ! , \l = Makes Working E a s ~ e r ! Check it out for value! 12" B & W TTL Monitor with anti-glare screen, pan/tilt base and front mounted controls. Exceptional value and quality! 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You can then plug the EGA card into one of the expansion slots on the motherboard (we chose slot three}. 34-way cable with lines 25-29 flipped goes to the the hard drive connector (J5}. Assuming everything checks out, clip the plastic card guides into position on the metal bracket behind the speaker, then install the disc controller on the mother board. As before, you must use one of the long expansion slots. Finally, plug the connector for the Disc indicator LED into J6 (red lead to pin 1, black to pin 2). Disc controller card The manual also shows JP5 and JP6 but, in practice, these don't exist at least not on our board. The 34-way and 20-way connector cables for the disc drives can now be plugged into the controller card at locations J1, J3 and J5. Check that the blue or red stripe on each cable goes to pin 1 of its matching connector (ie, towards the rear of the board}. Fit the 34-way cable with lines 10-16 "flipped" to the floppy disc connector (J1}; the There are two disc controller cards to choose from: either the X2014 floppy disc controller card or the X2008 hard/floppy disc controller. The floppy controller is considerably cheaper than the hard/floppy controller ($129 vs. $399), but the latter should be specified if you intend installing a 20 megabyte hard disc drive. Another reason for specifying the hard/floppy controller board: if you start out with just single or dual floppy drives, you can easily add a 20Mb hard drive later on. But don't be tempted to go for the more expensive controller if you're not likely to need it. We'll describe the installation procedure for the X2008 hard/floppy controller. First, check that the default settings of the jumper connectors are correct, as set out in the manual. In particular, pins 2 and 3 of JP1 and pins 1 and 2 of JP2 should be shorted, while JP3 should be open. This partly assembled machine includes the motherboard, hard/floppy disc controller and power supply. The disc cage fits in the bottom corner. 56 SILICON CHIP The X2012 1/0 card. Check the settings of SWl and SW2 before plugging it into the motherboard. The EGA card. Its switch block (top right hand corner) must be set to suit the type of display you intend to use. These two views show the locations of the plastic guides on the two disc drives. Note that the tapered ends go towards the rear. Disc drives The hard disc and floppy disc drives are both mounted in the disc cage previously removed from the c.a se. The hard disc is first. Locate the drive select jumper (J6) at the rear of the drive and make sure it's set to D2. Be careful not to drop or jar the drive - it's fragile. Similarly, locate drive select jumper Jl on the floppy drive. If your drive is labelled DSO through to D53 , set the jumper to DSl. If the drive is la belled DS 1 through to DS4 , then set it to DS2. The next step is to screw the four plastic guide rails to the sides of the drives. This is where we struck our first snag in the assembly. Figuring out the correct locations for the guides was a little tricky but we eventually got it right after some trial and error. To save you the same hassle, the accompanying photographs clearly show the locations of the guides. The two disc drives simply slide into the disc cage. The hard disc is first and should be installed with the diecast cover uppermost. Push the drive all the way in, then install the floppy drive. You will find that the bottom lip of the floppy drive initially overlaps the hard disc drive ever so slightly. A firm push is all that's needed to overcome the problem. The disc cage can now be carefully positioned in the chassis and slid forward so that the metal tongues engage the slots in the baseplate. Check that the drives mate correctly with the front panel opening, then secure the cage with the two self-tapping screws. Finally, the various power supply and disc controller connections can be made to the two drives. Locate the four-pin power connector from the hard disc and plug it into one of the polarised 4-pin power connectors from the power supply. A second 4-pin connector plugs into the floppy drive, directly above the hard disc supply leads. The 20-way and 34-way cables from the controller board plug directly into edge connectors on the DECF.M BER1987 57 back of the two drives. Install the cables for the hard drive first, then the cable for the floppy drive. Slots cut into the edge connectors ensure correct cable polarity. Note: the 34-pin edge connectors with the "flipped" sections are installed on the drives. The other ends go to the controller card. The middle connectors are used only if two drives of the same type are installed. Powering up Now for the big moment! Plug in the monitor and keyboard, remove the protective cardboard from the floppy disc drive, and switch on. After the BIOS logo appears, the floppy drive LED should come on briefly and the system should display the message "Disc boot failure, insert system disc and press enter". When that happens, all is well and you can insert your DOS disc and re-boot the computer. The system will then ask you to enter the date and time. Press ENTER twice to bypass this procedure. You should now have the DOS prompt A on the screen. If you run into problems here, check the drive select jumper on the floppy drive and the connections between the drive and the controller card. It is normal for the system to display an equipment configuration error message at this stage. This last problem is solved by running the system SETUP program. Details of the system setup are stored in a battery-backed RAM chip on the motherboard and are accessed by pressing the CTRL, ALT and ESC keys at the same time. Select option A and update each item as it appears. The program will ask you to enter the date and time, and will request information on the disc drives fitted, the amount of memory and the display adapter. Note that the hard disc drive supplied is a type 2. When you are satisfied that all the information is correct, press E to re-boot the computer. The system should now return to the DOS prompt A, although there will be quite a lengthy pause if you have specified a hard disc in the SETUP program. 58 SILICON CHIP The two disc drives slide into the disc cage. Treat the hard disc drive carefully and install it with its diecast section uppermost. A firm push will be needed to lift the bottom lip of the floppy drive over the top of the hard drive. Both keyboards feature click-action keys. The deluxe version (top) has a separate cursor pad and the function keys are mounted along the top. Actually, we struck another snag at this point. Despite frequent reruns, the system displayed an equipment configuration error ea ch time we tried to re-boot from the SETUP program. We solved the problem eventually when we realised that we should have been specifying the special adapter option for the primary display (because we had the EGA card), and not the monochrome option. At this stage, you will be unable to access the hard disc since it has yet to be initialised. That's easily fixed though. Insert the DSPREP disc supplied with the hard drive into drive A and type DSPREP. Now type INSTALL and press the ENTER key. After that, it's simply a matter of following the instructions on the screen to initialise the disc. This procedure will take several minutes. To begin with, the system will count down as it initialises all the cylinders on the hard disc, beginning with cylinder 615 . Then, when it reaches 0, it quickly counts back in the other direction. At the end of all this, the system will display the following message: Drive One is now low-level initialised. Strike a key when ready ... Formatting the hard disc You are now ready to partition and format the hard disc. Insert your DOS disc in Drive A, type FDISK and press ENTER. Unless you have software that requires a non DOS formatted area on your hard disc, you should use the entire disc as a DOS partition. As before, it's simply a matter of following instructions on the screen. When partitioning is complete, install DOS onto the hard disc by typing FORMAT C:/S/V and then pressing ENTER. After a few minutes, the system will report on the available disc space and you will have a system that can be booted from the hard disc. All plugged in and ready to go. Stow the disc drive cables and power connectors neatly so that they don't foul the disc drives or the lid of the case. We want one So what are our conclusions? Well, we wanted one. Well, two actually. The click action keyboards are nice to use, there's scads of memory and it's blindingly fast. " Speed thrills", they say and ain't it the truth. To someone used to working with a standard IBM PC, the speed of • PRINTED CIRCUIT BOARDS See Jemal for fast production of small to medium quantities, single and double sided, plated through holes , all finishes. Immediate computer quotes. • INSTRUMENT CONTROL PANELS Innovative approaches to improve your product • MEMBRANE SWITCH PANELS this AT-compatible machine is a real eye-opener. It goes like a rocket! We teamed our machine with a Multitech high-resolution monochrome monitor and it proved to be an ideal match. It is much sharper than an ordinary monochrome monitor . Again, we wanted it. Now then, let's have another look at those prices... le ,_o - 0 0 11111111 0 ° =----~ 11111111 ° ~ -------~ .. ( t , . ~ ---- = == == =; 0 '--0 :;-:: - - - -, T - ', ......... 0 Simple concept, sophisticated technology • PRECISION METALWORK 9-inch racks , chassis and enclosures • ASSEMBLY SERVICES In-house services to complete the " one stop shop" TECHNOLOGIES GENERAL OFFICE & MANUFACTURING FACILITY 5 FORGE STREET, WELSH POOL 6106, WESTERN AUSTRALIA TELEPHONE (09) 350 5555 FAX (09) 458 6539 TELEX 95494 DECE/\!HEfl 1987 59