Section 1C - PC Hardware Information
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Information in Part 1
1. Floppy Drive won't read second Disk
2. Microsoft's DMF 1.77 Floppy Disks
3. Delete any file
4. Run SCAN once a day
5. PC Response Times Compared
6. RAM Chip Speeds
7. RAM Chip Types
8. RAM Chip Part Numbers - Links to Manufacturers
9. CPU Voltages
10. Common Interrupts (listing)
11. Computer Bus Terms
12. Changing CMOS by Direct Editing
Information in Part 2
13. RS-232 Pin-outs and Signals
14. RS-232 Made Easy
15. Loop Back Plugs
16. Parallel Ports - SPP, EPP, ECP, and More
17. Sound Cable Fix (missing audio channel)
18. CD-ROM Drives and Audio Extraction
19. Burning CDs so they are easier to read...
20. Quantex Secrets
21. Reset Gateway Keyboard
22. AMI Happy Birthday BIOS Virus
Information in Part 3
23. AMD Win-BIOS Beep Codes
24. AMI BIOS Beep Codes
25. AMI BIOS Beep Codes - Ver 2
26. Phoenix Ver 1 Beep Codes (286/386/486)
27. Phoenix Ver 4 Beep Codes
28. How much Video Memory Do You Need?
30. Compaq BIOS Note
31. Using PAUSE to see BIOS Version
32. Flashing BIOS Warning!
Subject: Floppy Drive won't read second disk
Explanation: During an installation of software or reading the directory of multiple floppies the computer displays the file table of the first disk only.
Problem: Even though DOS spins the new disk as if it's reading it, it does not because as far as it's concern, the floppy was never changed.
Quick test: If you have more than one floppy drive, put a disk in the other drive, and do a directory on it. Then do a directory on the first drive. You will now see the correct file table. Why? Because DOS cleared the the information on the first disk when it read the second one.
Solution: DOS is not seeing the signal that the floppy door opened. Can be Drive, Cable, or Controller. Is usually bad floppy cable or cable is not fully seated. Go To Top
Subject: DMF or Distribution Media Format Floppies (Microsoft)
These 1.44 floppies contain 1.7 mb of compressed data (MS Office went from 31 disks to 24 with the new format).
Disk 1 will always be the standard 1.44 format as DOS cannot read the compressed files directly.
On disk 1 you will find a file EXTRACT.EXE.
If you run EXTRACT /?, you will get a help screen on how to use this file to get individual files out of these "file cabinets", the new name for this compressed format.
One of these switches will let you copy the compressed file from the floppy to your hard drive. (Before you can copy it to a new floppy, the new floppy has to be formatted to the 1.7 mb format.)
To copy the file, use this command:
EXTRACT /C A:\<FULLNAME>.CAB C:\<FULLNAME>.CAB
If you try and reverse this to copy it back to a standard 1.44 formatted floppy, it will copy the first 1.44 amount of data then crash.
************************************************************************* Option 1
A better option for making copies is using FDREAD and FDFORMAT, part of FDFORM18.ZIP available from many BBSs. It is from Germany and allows you to format, read, and write 1.7mb floppies.
FDREAD is a TSR that will automatically load itself high and allows your PC to read and write to and from 1.7mb floppies (will not work with DOS DiskCopy).
FDFORMAT a: /F:1.72
This will format your 1.44 floppies to 1.72.
So, load FDREAD, format some blank floppies with FDFORMAT, and start copying!
************************************************************************* Option 2
New on the scene is DCF494.ZIP, or version 4.94 of Disk Copy Fast. This will let you do Diskcopy with on the fly formatting. Go To Top
Subject: Delete any File
This seems really simple, but I get the question all the time, so here it is.
Just replace the strange or missing character with a "?". To delete a whole bunch of strange files use DEL ????????.???
What's the secret? An "*" assumes and standard character. A "?" stands for anything in that space whether it's a standard character or not. Go To Top
Subject: Run Scan Once a day
Using DOS you can make your PC run a virus scanner, or any other program just the first time you turn on your PC each day. Create the following batch file (just copy this file as filename.bat, and edit out the top and bottom of the page)
echo off echo. |date>today.txt fc /1 today.txt lastboot.txt|find "no" >nul if not errorlevel 1 goto skip cls echo. echo. choice /t:y,4 Do you want run SCAN now? if errorlevel 2 goto nope D: cd\vscan SCAN E: /REPORT D:\SCANE.RPT /RPTERR SCAN C: /NOMEM /REPORT D:\SCANC.RPT /RPTERR SCAN D: /NOMEM /REPORT D:\SCAND.RPT /RPTERR cd\ C: echo. |date>lastboot.txt goto end :nope cls @echo. @echo. @echo. @echo. @echo SCANing Cancelled! @echo. rem @pause > nul :END :skip cls Go To Top
Subject: PC Response times (All CPUs are Intel unless otherwise noted)
Hint: From 7 minutes to 2 seconds in 10 years....
This is the times for Release 8 AutoCAD (105K Drawing File) (runs w/o Co-Processor)
1.8 Seconds - P5-200, PCI bus, RAM Drive Micron, Intel Chipset, AMI Bios 4.0 P5-200, PCI bus, IDE Drive Micron, Intel Chipset, AMI Bios 1.9 P5-150, PCI bus, RAM Drive Micron, Intel Chipset, Phx Bios 4.0 P5-150, PCI bus, IDE Drive Micron, Intel Chipset, Phx Bios 1.8 P5-133, PCI bus, RAM Drive Micron, Intel Chipset, Phx Bios 4.6 P5-133, PCI bus, IDE Drive Micron, Intel Chipset, Phx Bios 2.4 P5-120, PCI bus, RAM Drive Intel Advanced/ZP MBoard 5.1 P5-120, PCI bus, IDE Drive Intel Advanced/ZP MBoard 2.8 P5-100, PCI bus, RAM Drive Clone PCI w/Intel Chipset 6.3 P5-100, PCI bus, IDE Drive Clone PCI w/Intel Chipset 3.5 P5-90, PCI bus, RAM Drive Intel Plato Motherboard 11.7 P5-90, PCI bus, IDE Drive Intel Plato Motherboard 3.6 P5-66, PCI bus, RAM Drive Computer Sales Professionals 7.1 P5-66, PCI Bus, IDE Drive 3.8 P5-60, PCI bus, RAM Drive ZEOS Pantera 6.5 P5-60, PCI bus, IDE 528 Drive ZEOS Pantera 3.6 P5-60, Local Bus, RAM Drive Dell 3.8 AMD 5x86-P75-133, RAM Drive UMC 486 PCI Motherboard 6.6 AMD 5x86-P75-133, IDE Drive UMC 486 PCI Motherboard 3.9 Cyrix P6-133, RAM Drive 4.0 486-100, Local Bus, RAM Drive 6.7 486-100, Local Bus, IDE Drive 4.8 AMD 5x86-P75-133, RAM Drive UMC 486 VESA Motherboard 9.2 AMD 5x86-P75-133, IDE Drive UMC 486 VESA Motherboard 6.2 486-50, Local Bus, RAM Drive 11.6 486-50, Local Bus, from Hard Drive 5.9 486-66 Micronics, Local Bus, RAM Drive Gateway 12.6 486-66 Micronics, Local Bus, IDE Drive Gateway 12.1 486-33, RAM Drive Opti Chipset, AMI 12.6 486-33, IDE Drive Opti Chipset, AMI 12.3 486-25, RAM Drive Micronics Motherboard 19.8 486-25, IDE Drive 15.6 AMD 386-40, Co-Processor, RAM Drive Opti Chipset 22.0 AMD 386-40, Co-Processor, MFM Drive, 1:1 Controller 32.2 AMD 386-40, Co-Processor, IDE Drive 24.3 386-25, Co-Processor, RAM Drive Unisys 39.6 386-25, Co-Processor, IDE Drive Unisys 54.2 386-25, Co-Processor, SCSI Drive Unisys 65.0 AMD 386-40, RAM Drive Opti Chipset 74.0 AMD 386-40, IDE Drive Opti Chipset 76.0 386-33, RAM Drive 84.0 386-33, SCSI Drive 45.9 386sx-16, Co-Processor, RAM Drive 54.8 386sx-16, Co-Processor, MFM Drive, 1:1 Controller 79.8 386sx-16, Co-Processor, IDE Drive 98.0 286-12, Co-Processor, MFM Drive Phoenix BIOS 2:42 Min:Sec 386-20, RAM Drive 2:30 386-30, MFM Stacker 3.1 Drive 3:41 386sx-16, IDE Drive 7:48 286-8, MFM Drive HP Vectra
NOTE: Test runs faster without a mouse driver loaded. Most tests were run without a mouse. 09-24-96 Go To Top
Subject: RAM Chip Speeds
Minimum timing requirements for PC Memory Chips ---------------------------------------------------
PC BUS Chip Speed (in MHz) (in Nano-Seconds) (zero wait states) (one wait state)
4.77 410 8.0 250 Note: slowest chip available 12.0 166 is 150 Micro-Seconds
16.0 126 189 20.0 100 150 25.0 80 120
33.0 60 90 50.0 40 60 66.0 30 45
100.0 20 30 133.0 15 22 200.0 10 15
These numbers derived by dividing one by the clock cycles (this equals the time in micro-seconds of one clock cycle), then multiply it by two (it takes two cycles to do a fetch and read). Slower chips can be used if you add "wait states" or do-nothing cycles.
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Subject: RAM Chips Types
Memory Information....(Note: Packard Bell Memory is Special, not interchangeable!)
What is the difference between ECC and non-parity memory? Is there a performance difference?
ECC is indicated by a 36 or 72 in the part number. Non-parity is designated with a 32 or 64. If you already have a PC and are unsure which type you have, count the number of small, black, IC chips mounted on one of your existing DIMMs. If the number of chips is evenly divisible by three, then you need ECC. If the number of chips is NOT evenly divisible by three, you have non-parity memory.
If you are building a PC and deciding which type to use, the following guidelines should help. If you plan to use your system as a server or a similar mission critical type machine, it is to your advantage to use ECC. If you plan to use your PC for regular home, office, or gaming applications, you are better off with non-parity.
ECC (Error Checking and Correcting) performs "double bit detection and single bit correction." This means that if you have a single bit memory error, the chipset and memory will find and repair the error on the fly without you knowing that it happened. If you have a double bit memory error, it will detect and report it. Using ECC decreases your PC's performance by about 2%. Current technology DRAM is very stable and memory errors are rare, so unless you have a need for ECC, you are better served with non-parity SDRAM.
What do 16x64, 16x72, etc. represent when describing memory, and how do they affect what I should buy?
If you are shopping by motherboard, you may see the size of your module written in the format 16Meg x 64, 16Meg x 72, etc. In this format, the second number gives the width of the data path in bits. If this number is divisible by nine, it is a parity or ECC module; otherwise, it is a non-parity module.
You can determine the size of your module from this format by multiplying the two numbers together, then dividing by eight or nine, whichever results in an even number. This gives you the size of your module in megabytes (MB).
What is the difference between a DIMM and a SIMM?
DIMM stands for dual inline memory module, and SIMM stands for single inline memory module. The gold or tin pins on the lower edge of the front and back of a SIMM are connected, providing a single line of communication paths between the module and the system. The pins on a DIMM are not connected, providing two lines of communication paths between the module and the system, one in the front and one in the back.
SIMMs and DIMMs are not interchangeable; they are different sizes and they install into different types of sockets.
SDRAM (synchronous dynamic random access memory) is one type of DRAM (dynamic random access memory). Other types of DRAM include FPM (fast page mode) and EDO (extended data out).
Extended data out (EDO) memory and synchronous dynamic random access memory (SDRAM) are two different types of memory technology. SDRAM is the newer, faster type of the two. The biggest difference between the two is that SDRAM is synchronized to the CPU clock.
Synchronous graphics random access memory (SGRAM) is a type of DRAM that is designed for graphics hardware requiring high-speed throughput for applications such as 3-D rendering and full-motion video. SGRAM is often integrated into your motherboard or graphics card.
SDRAM and SGRAM are not interchangeable
Extended data out (EDO) and fast page mode (FPM) are two different types of memory technology. FPM is the oldest type of memory that and is used primarily in 386, 486, and early Pentium systems. In the FPM scheme, information from the same row of DRAM can be accessed an infinite number of times after supplying the row address only once.
EDO memory came into use in 1995 and is found in some Pentium and Pentium II systems. Enhancements in its addressing system allow EDO to operate 10 to 15% faster than FPM.
Virtual channel RAM (VCRAM) is a proprietary type of SDRAM. Very few systems accept VCRAM; however, those that take VCRAM will also accept standard SDRAM.
If your system already has VCRAM, you can add standard SDRAM, but you need to follow a particular pattern for which type of memory goes into which slot in your system. To find the configurations that will work, see Micronpc.com support.
DDR SDRAM comes in two speeds: PC1600 and PC2100. Despite what these names imply, DDR is twice as fast as PC100, not roughly twenty times faster.
PC100 SDRAM modules have a bandwidth (the amount of data they can move) of 0.8GB/sec. Since DDR SDRAM can move data twice as fast as SDR SDRAM, 200MHz DDR (100MHz doubled) has the bandwidth of 1. 6GB/sec, or 1600MB/sec. Hence, the name PC1600. 266MHz DDR SDRAM (133MHz doubled) has the bandwidth of 2.1GB/sec and is referred to as PC2100.
DDR and Rambus DRAM are two new types of memory promising to make computers run faster. But before we discuss them, relax! They will NOT make SDRAM obsolete in the near future.
First, let's start with a quick review. In the last few years, SDRAM (synchronous DRAM) has become the standard type of memory for PCs. The main reason for this is that SDRAM is tied to the front-side bus clock in your system. SDRAM and the bus execute instructions at the same time rather than one of them having to wait for the other. As bus speeds have increased to 100MHz and beyond, this has improved system performance.
DDR SDRAM DDR (Double Data Rate) memory is the next generation SDRAM. Like SDRAM, DDR is synchronous with the system clock. The big difference between DDR and SDRAM memory is that DDR reads data on both the rising and falling edges of the clock signal. SDRAM only carries information on the rising edge of a signal. Basically this allows the DDR module to transfer data twice as fast as SDRAM. For example, instead of a data rate of 133MHz, DDR memory transfers data at 266MHz.
DDR modules, like their SDRAM predecessors, are called DIMMs. They use motherboard system designs similar to those used by SDRAM, however DDR is not backward compatible with SDRAM designed motherboards. DDR memory supports both ECC (Error Correction Code, typically used in servers) and non-ECC (used on desktops/laptops.)
Rambus DRAM Rambus memory (RDRAM) is a revolutionary step from SDRAM. It's a new memory design with changes to the bus structure and how signals are carried. Rambus memory sends less information on the data bus (which is 18 bits wide as opposed to the standard 32 or 64 bits) but it sends data more frequently. It also reads data on both the rising and falling edges of the clock signal, as DDR does. As a result, Rambus memory is able to achieve effective data transfer speeds of 800MHz and higher.
Another difference with Rambus memory is that all memory slots in the motherboard must be populated. Even if all the memory is contained in a single module, the "unused" sockets must be populated with a PCB, known as a Continuity Module, to complete the circuit.
Rambus DRAM modules are known as RIMM modules (Rambus Inline Memory Modules). Rambus memory supports both ECC and non-ECC applications.
Production Challenges One of the challenges Rambus memory currently faces is that it is expensive to produce compared to SDRAM and DDR. Rambus memory is proprietary technology of Rambus Inc. Manufacturers that want to produce it are required to pay a royalty to Rambus Inc., whereas DDR designs are open architecture. Other cost factors for Rambus memory include additional module manufacturing and testing processes and a larger die size. Rambus die (chips) are much larger than SDRAM or DDR die. That means fewer parts can be produced on a wafer. For more information on manufacturing memory, see Micron Manufacturers
Many major computer makers announced Rambus systems in late 1999. These initial systems use motherboards built around the Intel 820 (Camino) or 840 chip sets.
Performance Now for the million-dollar question: How do DDR and Rambus memory compare performance wise? - that depends. Both technologies have their own ardent supporters and we have seen several different benchmarks to date that provide conflicting results.
On the surface, it seems simple: Data flow at 800MHz is faster than data flow at 266MHz, right? Unfortunately, it isn't that simple. While Rambus modules may have the ability to transfer data faster, it appears to have higher latency (the amount of time you have to wait until data flows) than that of a DDR system. In other words, the first data item transferred in a Rambus transaction takes longer to initiate than the first data item moved in a DDR system. This is due in part to how the systems are constructed.
In a DDR or SDRAM system, each DIMM is connected, individually and in parallel, to the data bus. So whether you have a single DIMM or multiple DIMMs, the amount of time it takes to initiate a data transfer is effectively unchanged.
In a Rambus system, RIMM modules are connected to the bus in a series. The first data item transferred must pass through each RIMM module before it reaches the bus. This makes for a much longer distance for the signal to travel. The result is higher latency. That's not necessarily a problem in an environment where data transactions involve lengthy streams of data, such as gaming. But it can become an issue in environments where many small transactions are initiated regularly, such as a server.
To further explain, here's an example that we can all relate to - driving your car to the store. You can take the roundabout freeway and drive 20 miles at 70 MPH. Or, you can take a more direct route and drive just 5 miles at 50 MPH. You might go faster on the freeway but you'll get to the store (Memory Controller) faster on the straight-line route.
Looking to the Future So which technology will become the memory of choice for the computer industry? That probably won't be clear until sometime in the near future. However, it really doesn't matter to a certain extent.
Generally speaking, motherboards are built to support one type of memory. You cannot mix and match more than one type of SDRAM, DDR, or Rambus memory on the same motherboard in any system. They will not function and, in many cases, will not even fit in the sockets. The right type of memory to use is the one that your motherboard takes! And no matter what type of memory you use, more is typically better. A memory upgrade is still one of the most cost-effective ways to improve system performance.
At this point in time, the market for DDR and Rambus memory is relatively small.
DDR transfers data twice as fast as SDR SDRAM modules. This doesn't mean your system will run twice as fast, but your memory will. And the faster memory will improve your PC's performance.
My motherboard supports SPD and non-SPD memory. What's the difference and which is better?
SPD (serial presence detect) is a small non-volatile RAM chip attached to SDRAM modules that contains information about the memory. This information includes the number of row addresses, number of column addresses, error detection/correction, refresh rates, data width, and the interface standard. It also contains less important information such as the module serial number and manufacturer code. When your computer powers up, it sets the row and column settings and the timings for the module based on the information in the SPD.
SPD is required in SDRAM that is 66MHz, PC100 and PC133 compliant. Standards set by Intel and JEDEC ensure that data is entered in appropriate locations so the motherboard BIOS can understand what this data means. The SPD standard allows greater flexibility for incorporating identification of new features and technologies on memory modules.
What is the difference between buffered and registered memory?
DDR and SDRAM can be unbuffered or registered. EDO and FPM can be buffered or unbuffered. Buffered modules contain a buffer to help the chipset cope with the large electrical load required when the system has a lot of memory. Registered modules are unbuffered modules that contain a register that delays all information transferred to the module by one clock cycle. Buffered and registered modules are typically used only in servers and other mission-critical systems where it is extremely important that the data is properly handled.
What is the difference between 3.3V modules and 5V modules?
Some systems require 3.3-volt modules, and others require 5-volt modules. The two are not interchangeable, and the different modules actually have slightly different notches so that you won't accidentally install a 5V part in a 3.3V slot or vice versa.
What is the difference between 7.5ns and 8.0ns?
8.0ns (8-nanosecond) parts are PC100 compliant and are designed for use with a 100MHz front side bus. Our 7.5ns parts are PC133 compliant and are designed for use with a 133MHz front side bus.
You can use PC133 modules with a 100MHz front side bus and vice versa. However, keep in mind that your memory will only be as fast as the slowest "link" in the system. If you install PC133 modules with a 100MHz front side bus or PC100 modules with a 133MHz front side bus, your memory will only run at 100MHz.
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Subject: RAM Chips Part Numbers - LINK to Manufacturers
Samsung Memory Chip Part Diagram
Memory.Com Part Number Listing
Micron Memory Index page for many options on part numbers
Micron Memory Data Sheets
ASI Memory - Scroll Down long page
Link to Links page for all Memory Manufacturers
Type in your current Part Number to determine type
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Subject: CPU Core Voltages
AMD 486- 40,80 DX2-66 DX4-100,120 (3.45 Volts)
AMD 5x86-133 (3.45 Volts)
AMD K5- 75,90,100,120,133,166 (3.52 Volts)
AMD K6- 166,200 (2.9 Volts) 233 (3.2 Volts) 266,300 (2.2 Volts)
AMD K6-2- 300,333,350,366,380,400,450 (2.2 Volts)
AMD K6-3- 400,450,500 (2.4 Volts)
Athlon - 500 to 750 (1.6 Volts) 800,850 (1.7 Volts) 1Ghz (1.8 Volts)
486SX- 16,20,25,33 (3.3 or 5 Volts)
486DX- 25,33,50 (3.3 or 5 Volts)
486SX2-50 (3.3 or 5 Volts)
486DX2- 50,66 (3.3 or 5 Volts)
486DX4- 75,100 (3.3 Volts)
Classic Pentium (P54C) 60,66 (5v) 75,90,100,120,133,150,166,200 (3.3v)
Pentium Pro 166,180,200 (3.3 Volts)
Pentium MMX (P55C) 166,200,233 (2.8 volts) 266 (1.9 or 2.0 volts)
Some low-power 166 units use 1.8 or 1.9 volts - check model number
on Intel web site.
Pentium II 233,266,300 (2.8 Volts) 333,350,400,450 (2.0 Volts)
Pentium Celeron 300,360,433 (2.0 Volts)
Pentium III 450,500,550 (2.0 volts) 600 (2.05 volts) 650,667,700,733,
800,850,866 (1.65 volts) 1Ghz (1.7 volts) Go To Top
Subject: Interrupts Listing
AT Common Base Port Addresses
Address IRQ DMA ------- --- --- AT Hard disk 1F0 14 Floppy disk 3F0 6 2 Compaticard 370 6 2 SCSI 340,288 11 5,6 Tape 280 4 (also see floppy controller)
Monochrome adapter 3B0 Hercules mono adaptor 3B4 CGA adaptor 3D0 EGA adaptor 3C0,03H 2 VGA adaptor 102,46E8 2,12 Video Ram B00 3 EGA/VGA ROM BIOS C00 4
LPT1 378,3BC 7 LPT2 278 5
COM1 3F8 4 COM2 2F8 3 COM3 3E8 4 or 10 COM4 2E8 3 or 11
Game 200 15
Serial Mouse (see serial port) PC Mouse Bus Mouse 338 10 or 238/15 Microsoft Bus Mouse 023C 2
Voice Card 300 Sound Blaster Sound Card 220 5 1 Pro Audio Sound Card 388,220 7 3
Scanners 280,3E0,2EC 2,3,5 EPROM Programmers 280
Old LAN Card 300,360 9 (AT) or 2 (XT) New LAN Card 300,280 3 6
System Timer 0 System Clock 8 System Co-Processor 13 TSR's 9
Mostly Unused 12,15 Go To Top
Subject: Computer Bus Terms
ISA - Industry Stand Architecture - 8 and 16 bit bus, 8 Megahertz
EISA - Enhanced Industry Stand Architecture - 32 bit bus and was the first go at increasing bus speed above 8 MHz. An EISA slot can accept an ISA or EISA card.
VESA - Video Electronics Standards Association; First standard designed for the Local bus, referred to as VL-Bus, or VESA Local Bus. VL-Bus was a quickly-formed, low cost standard to get on the market. Drawback is that performance degrades when more than two VL-Bus cards are used. 32 bit bus, runs at memory bus speed.
PCI - Peripheral Component Interconnect; Designed by Intel as a high-end alternative to VL-Bus. 32 bit bus, runs at memory bus speed.
SCSI - Small Computer Systems Interface. SCSI Controllers plug into all of the above buses depending on card type, and create a bus that can theoretically control seven devices such as hard drives, tape drives, and CD-ROM drives. Go To Top
Subject: Changing CMOS by direct editing of CMOS Memory (conceived by John Rizzuto 10-95)
Ever have an older PC that you are totally unable to get into the setup routine and correct a setup problem? Then go through the back door. Here's how it works. We had an older 386-20 that would always boot up in the slow or non-turbo mode which required us to hit the Control-Alt-Keyboard + to kick it into turbo on boot up. We tried everything, running every program we could find to get into setup or emulate those keyboard keystrokes with no success. Then John said just edit the BIOS.
There are a number of small programs that will fetch the BIOS or write it to the PC. Once you have one of these programs find a PC that is has the same BIOS manufacture and option that you are trying to change. Run the program (print the screen), change the option, reboot, run the program again, and print the screen. Then see what bit/s changed.
Below is an example of a BIOS memory:
** CMOS -- "CMOS RAM <-> file" transfer utility ** ** Version 1.0 Copyright (C) 1987 by Alan D. Jones **
Current CMOS RAM contents:
0 1 2 3 4 5 6 7 8 9 A B C D E F 00 : 15 24 19 06 07 02 01 27 10 95 26 02 40 80 00 00 10 : 42 91 12 00 0E 80 02 00 3C 00 A0 FF FF FF 0A 39 20 : 00 00 00 00 00 00 00 00 50 00 00 00 00 00 05 E1 30 : 00 3C 19 80 F0 00 00 09 00 00 00 00 00 00 00 00
Checksum = 05 91
Contents on line 00 will change because of the real time clock changes. Most of the special features that you can't get to in any of the standard setup programs will be found on line 30. The speed boot up change is usually between 34 and 37. Be sure to note what you changed so you can't back out of any change you make. In the example above the value of 37 = 09. To make the this computer boot up in the slow mode, all I have to do is change this value to 08. On the older PC it was at 34 which had a value of 80. When I changed it to 90 I found I now had different tone beeps when I changed speeds. When I changed it to 91 it now booted up in FAST mode, and our problem was fixed.
These files will be in a binary format, so you will need a binary editor to change the values. I used Xtree Gold.
If you ever have to do this, be patient while trying different values. If your change had no obvious change, set the value back to what it was and try a different address location or different value.
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