A LILO BUG

With LILO versions below v21 there is another disadvantage: the address conversion done at boot time has a bug: when c*H is 65536 or more, overflow occurs in the computation. For H larger than 64 this causes a stricter limit on c than the well-known c < 1024; for example, with H=255 & an elderly LILO must have c < 258. (c=cylinder where kernel picture lives, H=number of heads of disk)

LILO is a bit fragile, it requires the discipline of running /sbin/lilo each time installs a new kernel. Some other boot loaders do not have this disadvantage. Especially grub is popular these days; a major disadvantage is that it does not support the lilo -R label function.

If you are upgrading the kernel on your Slackware-9.1 process (say, to
five.4.23 due to the recent security announcement) you might run in to this
scary issue when you run lilo:
Deadly: volid read error
or this:
Deadly: open /dev/hdd: Input/output error
(where hdd is my ZIP drive - definitely not in my lilo.conf).
When this happens, LILO will refuse to put in the new loader & map.
This is a bug in lilo-22.5.7.2 included in Slackware-9.1. Lilo scans
/proc/partitions & then tries to read from any partitioned tool to find
something called the Volume ID. Failure to read from a tool is deadly. In
the above examples, the first error is from my USB flash disk, which is
unplugged - but /proc/partitions still has an entry for "sda1", & the
second is from my ATAPI ZIP drive /dev/hdd, which is empty.
But, I think you can use the from cheat code in your lilo.conf file to specify which drive to load from.

This is fixed in lilo-22.5.8 ("Volume ID scan bypasses disks marked
inaccessible"). If, like me, you don't require to upgrade lilo, you require to
make sure there's no entries in /proc/partitions for inaccessible,
partitioned drives before you run lilo. Ways to do this include inserting
disks or plugging in USB devices (no require to mount them), or unloading
modules. Or reboot & run lilo before you first mount a removable
disk, since the /proc/partition entry appears to be created the first time
you use the disk.

CCD vs. CMOS

CCD (charge coupled device) and CMOS (complementary metal oxide semiconductor) picture sensors are different technologies for capturing images digitally. Each has unique strengths and weaknesses giving advantages in different applications. Neither is categorically superior to the other, although vendors selling expertise have usually claimed otherwise. The current situation and outlook for both technologies is vibrant, but a new framework exists for thinking about the relative strengths and opportunities of CCD and CMOS imagers.

Both types of imagers convert light in to electric charge and process it in to electronic signals. In a CCD sensor, every pixel's charge is transferred through a limited number of output nodes (often ) to be converted to voltage, buffered, and sent off-chip as an analog signal. All of the pixel can be dedicated to light capture, and the output's uniformity (a key factor in picture quality) is high. In aCMOS sensor, each pixel has its own charge-to-voltage conversion, and the sensor often also includes amplifiers, noise-correction, and digitization circuits, so that the chip outputs digital bits. These other functions increase the design complexity and reduce the area obtainable for light capture. With each pixel doing its own conversion, uniformity is lower. But the chip can be built to require less off-chip circuitry for basic operation.

CCDs and CMOS imagers were both invented in the late 1960s and 1970s (DALSA founder and CEO Dr. Savvas Chamberlain was a pioneer in developing both technologies). CCD became dominant, primarily because they gave far superior images with the fabrication expertise obtainable. CMOS picture sensors necessary more uniformity and smaller features than silicon wafer foundries could deliver at the time. Not until the 1990s did lithography create to the point that designers could start making a case for CMOS imagers again. Renewed interest in CMOS was based on expectations of lowered power consumption, camera-on-a-chip integration, and lowered fabrication costs from the reuse of mainstream logic and memory device fabrication. While all of these benefits are feasible in theory, achieving them in practice while simultaneously delivering high picture quality has taken far more time, money, and process adaptation than original projections suggested.

Costs are similar at the chip level. Early CMOS proponents claimed CMOS imagers would be less costly because they could be produced on the same high-volume wafer processing lines as mainstream logic or memory chips. This has not been the case. The accommodations necessary for lovely imaging perfomance have necessary CMOS designers to iteratively create specialized, optimized, lower-volume mixed-signal fabrication processes--very much like those used for CCDs. Proving out these processes at successively smaller lithography nodes (0.35um, 0.25um, 0.18um...) has been slow and expensive; those with a captive foundry have an advantage

Both CCDs and CMOS imagers can offer excellent imaging performance when designed properly. CCDs have historically provided the performance benchmarks in the photographic, scientific, and industrial applications that demand the highest picture quality (as measured in quantum efficiency and noise) at the expense of method size. CMOS imagers offer more integration (more functions on the chip), lower power dissipation (at the chip level), and the likelihood of smaller method size, but they have often necessary tradeoffs between picture quality and device cost. Today there is no clear line dividing the categories of applications each can serve. CMOS designers have devoted intense work to achieving high picture quality, while CCD designers have lowered their power requirements and pixel sizes. As a result, you can find CCDs in low-cost low-power mobile phone cameras and CMOS sensors in high-performance professional and industrial cameras, directly contradicting the early stereotypes. It is worth noting that the producers succeeding with "crossovers" have always been established players with years of deep experience in both technologies.

Change the CMOS Battery

The first signs that your battery is failing is that your clock began to run slow & you will notice that your computer keeps forgetting the date & time or your computer is having an issue finding & accessing positive peripherals or your PC refuse to boot, displaying a "CMOS Checksum Errors" or "System Configuration Lost message". When you experince those signs it's time to change your CMOS battery.

Before you jump on replacing your CMOS batter, safety rules first. The inside of a computer is a bad place filled with electricity & sharp edges. Make positive that your computer is unplugged from it's power source. Even be cautious on the inside of your computer,  most computer cases are unfinished metal & has sharp edges.

Here are the following tools you need to change your CMOS battery :

1. a X-point screwdriver

2. an anti-static strap(optional but recommended)

3. a new battery (seems logical)

 Then, this is the steps :

• First, When you remove the elderly battery from the motherboard, the information that's stored in the CMOS will be lost, so you ought to write down the BIOS settings.
• Unplug all the cables from the back of the computer, in the event you are not familiar about the ports at the back of your computer you ought to make a note  on where they came from so you can basically put them back when your done.
• Move the computer somewhere where you can work on it with ease.
• Remove the cover by locating the screws around the outer edge  at the back of your computer. Some computer cases only need you to remove four screws on side then a panel can be removed allowing you access to the computers insides, others you must remove 6 screws & remove the whole case by sliding it to the rear & lifting it off.
• Now make positive that you read & understand the safety instructions about static. Dangers of a Static Electricity
• Look inside & will see a round silver thing that's a size of bottle cap. Carefully lift the retaining clip & slide the battery out.
• Back to your computer insert the new battery by lifting the clip & sliding the battery in.
• Reinstall your case & plug all the cables back (you did keep in mind to label them didn't you)
• Power on your computer & check the bios, In the event you look carefully you will notice a line that says something like press del for setup or some other key (F2 or ESC or tab) this will take you to god's house (the BIOS) where you can make lots of changes to the way your machine works.
• You will now be introduced with a blue screen with lots of options on it, The they would like is load optimised/default settings.
• Exit & save your BIOS setting, your computer should now reboot.

Video BIOS ??

The video BIOS or firmware contains the basic program, which is usually hidden, that governs the video card's operations & provides the instructions that permit the computer & program to interact with the card. It may contain information on the memory timing, operating speeds & voltages of the graphics processor, RAM, & other information. It is sometimes feasible to change the BIOS (e.g. to enable factory-locked settings for higher performance), although this is usually only completed by video card overclockers & has the potential to irreversibly damage the card. (taken from wiki)

Resetting BIOS

CMOS Jumper

BIOS password is the password key is required to log into the BIOS Technique. It turned out to reset the Bios password is not difficult for most machines.

There are many ways to reset the BIOS password, like pulling the bios battery from motherboard, then pair it again after waiting about ten minutes, or move the BIOS's jumper to "reset the BIOS" on your motherboard. But this way is quite difficult, and it can not be applied on multiple machines to your motherboard.

This application supports all 32-bit operating system and 64-bit, except for Windows 95 and Windows NT six.51, because the operating system is the old operatingsystem. For that you can use the previous version of this program. CHMODDe-Animator is now able to check automatically at startup. After successful execution, the status of "Ready to go" look, the application can be used even by non-privilegedaccount on your computer (for instance under a user account)

There is now emerging a program to reset the BIOS password of CMOSDe-Animator V2 which recently released version six. CMOS De-Animator V2 is a utility for the technique of CMOS RAM. You can use these tools well to remove the password or to restore the BIOS password. You can also save the settings in a filethat can later be useful if you want to reset the password back 

What is CMOS ?

CMOS (complementary metal-oxide semiconductor) is the semiconductor technology used in the transistors that are manufactured in to most of today's computer microchips.

• Semiconductors are made of silicon and germanium, materials which "sort of" conduct electricity, but not enthusiastically. Areas of these materials that are "doped" by adding impurities become full-scale conductors of either extra electrons with a negative charge (N-type transistors) or of positive charge carriers (P-type transistors).
• In CMOS expertise, both kinds of transistors are used in a complementary way to form a current gate that forms an effective means of electrical control. CMOS transistors use very no power when not needed. As the current direction changes more quickly, however, the transistors become hot. This characteristic tends to limit the speed at which microprocessors can operate.
• Personal computers also contain a small amount of battery-powered CMOSmemory to hold the date, time, and system setup parameters.

How to Change BIOS Password

BIOS stands for Basic Input Output Method. That program is in the programmed computer's motherboard. His job is to record information about what equipment is connected to the motherboard, and also run the computer at start (before entering the program on Hard Disk).

In case you are afraid there's others who require to alter the settings in the BIOS. You can protect with a password. To generate a BIOS password, to enable the computer press "Del" or "F2" depending on the brand motherboard and BIOS version you use. This will raise the main menu of the BIOS, with the help of directional keys on your keyboard to navigate the "Supervisor Password". Type the password you require. This ought to be something you keep in mind write and store in a safe place. then restart to return in to your BIOS settings

How to Upgrade BIOS

To upgrade the BIOS, you need 2 files, first the BIOS file itself and the Flash Memory Writer utility, which is software to upgrade (flash) the BIOS, for example AFLASH.EXE, AWD816a.EXE and others. BIOS file usually with extension 001, BIN or any other, a bunch of size less than 512 KB. Most To upgrade the BIOS must be done through DOS or MS-DOS, although now also has a lot of vendors that provide software-based Windows. 


*) Noteworthy is the right search of the BIOS file and the Flash Writer , because if it does not match, the computer probably is not going to live longer. But if the type is correct, then chances are always successful, except for power failure or the computer is off when flash BIOS is running. 


In general, the BIOS flash lasts only a few seconds.Less than 30 seconds. To flash the BIOS, go to DOS, type the name of the Flash Writer, for example, to AWD816a.EXE C: \ ADW816a Then there is usually a description of how to use. Follow the instructions there, be sure to backup the old BIOS, it can be done with the flash file writer as well. Details shown may vary. If still in doubt, should be asked to know better. Or it could also be read in the user guide motherboard.
Where to Download the BIOS and Flash Utility? If we include the popular motherboard, the vendor usually has to provide downloads BIOS and Flash Utility her, like MSI, Gigabyte and the like. 
Here are some links to download BIOS and motherboard drivers which can be used as a reference: 

• ASUS Motherboard 
• ECS Web Site 
• GIGABYTE Motherboard 
• Micro Star International (MSI) Motherboard 
• To download various drivers > DriverStock

What Kind of Virus Could Damage BIOS ??

This is how a person could damage the BIOS, but I suggest not to do  it on your friend's PC..

1. Copy your fake BIOS file to a USB drive. It is best if this file is a BIOS for a different model of motherboard, but some older BIOS utilities may erroneously accept any file, even media or document files. Leave the USB drive connected.
2. Restart your computer. Before the computer lots Windows, look for the message reading "Press [Key] to enter setup." This key is usually Delete or F2, but this may vary between computers. Press this key quickly to enter BIOS. In case you do not press this key quickly , Windows will load. If this happens, basically repeat this step.
3. Type the full name of the file on your USB drive in to the command prompt window. Press "Enter." The command prompt will ask in case you need to update your BIOS. Press the "Y" key. The BIOS will now be rewritten with the fake BIOS file. If this is thriving, your motherboard will no longer be operable.
4. Select the "Boot" tab using the arrow keys. Find your USB drive within the list of boot devices. Use the arrow keys to highlight this drive. Press the appropriate key to save your changes & exit (the proper key to do this will be indicated on the bottom of your screen). Your computer will now restart & launch the command prompt window.

When BIOS Must be Upgraded?

There are some things that cause the BIOS must be upgraded, for example:

• When the computer starts, suddenly it stops before entering the operating system.
• Computer's age is long enough, and the installed new hardware that is not detected properly, for example, we replace the new processor. Because they often do not recognize theprocessor in the BIOS.
• BIOS is damaged, either indicated by the message or not. For example an invalid BIOS, the BIOS is corrupted and so on.
• BIOS fails to detect the hardware, such as hardiks, CD-ROM, VGA and other
• Wants a better performance of computer (hardware)
• The reccomendation from the motherboard's vendor

Things that Could Damage BIOS

If the BIOS on the computer is damaged, it can not automatically run the operating system like Windows XP for example.A few things that can cause damage to the BIOS, for example:

• Turn off your computer without shutdown, or sudden power off (without UPS)
• Hit by Virus
• Error upgrade the BIOS. For example the computer is off when the upgrade process, the BIOS does not match the type of motherboard etc..
• You most likely suffered from a power problem 
• Updating or "flashing" a motherboard is the method of installing new BIOS program. If that program is incompatible together with your hardware, you can kiss your computer good-bye.

Booting

Everytime you turn on your computer, the first thing you see is the BIOS application doing its thing. On plenty of machines, the BIOS displays text describing things like the amount of memory installed in your computer, the type of hard disk & so on. It turns out that, in the work of this boot sequence, the BIOS is doing a exceptional amount of work to get your computer prepared to run. This section briefly describes a number of those activities for a typical PC.

After checking the CMOS Setup & loading the interrupt handlers, the BIOS determines whether the video card is operational. Most video cards have a miniature BIOS of their own that initializes the memory & graphics processor on the card. In the event that they do not, there is usually video driver knowledge on another ROM on the motherboard that the BIOS can load.

Next, the BIOS checks to see if this is a cold boot or a reboot. It does this by checking the worth at memory address 0000:0472. A value of 1234h indicates a reboot, & the BIOS skips the remainder of POST. Anything else is thought about a chilled boot.

If it is a chilled boot, the BIOS verifies RAM by performing a read/write check of each memory address. It checks the PS/2 ports or USB ports for a keyboard & a mouse. It looks for a peripheral part interconnect (PCI) bus &, if it finds, checks all the PCI cards. If the BIOS finds any errors in the work of the POST, it will notify you by a series of beeps or a text message displayed on the screen. A mistake at this point is always a hardware issue.

Configuring Your BIOS

The BIOS checks the CMOS Setup for custom settings. Here's what you do to change those settings.

To enter the CMOS Setup, you must press a sure key or combination of keys in the work of the initial startup sequence. Most systems use "Esc," "Del," "F1," "F2," "Ctrl-Esc" or "Ctrl-Alt-Esc" to enter setup. There is usually a line of text at the bottom of the display that tells you "Press ___ to Enter Setup."

One time you have entered setup, you will notice a set of text screens with a lot of options. Some of these are standard, while others vary according to the BIOS manufacturer. Common options include:

• Technique Time/Date - Set the technique time and date
• Boot Sequence - The order that BIOS will try to load the operating technique
• Plug and Play - A standard for auto-detecting connected devices; ought to be set to "Yes" if your computer and operating technique both support it
• Mouse/Keyboard - "Enable Num Lock," "Enable the Keyboard," "Auto-Detect Mouse"...
• Drive Configuration - Configure hard drives, CD-ROM and floppy drives
• Memory - Direct the BIOS to shadow to a specific memory address
• Security - Set a password for accessing the computer
• Power Management - Select whether to make use of power management, as well as set the amount of time for standby and suspend
• Exit - Save your changes, discard your changes or restore default settings

How BIOS works ?

      The most common makes use of of of Flash memory is for the BIOS of your computer. On virtually every computer available, the BIOS makes positive all the other chips, hard drives, ports & CPU function together.
When you start your computer, the Central Processing Unit (CPU) tries to execute its first instruction; it's to get the instruction from somewhere. It cannot get it from the operating technique because the operating technique is located on a hard drive, the CPU cannot get to it without some instructions that will tell it how.
      The CPU sends control of the PC to the BIOS process.The BIOS is part of a power-on self-test of the computer. This check verifies your PC's hardware before booting. It informs the computer about all the devices that are attached to the PC. The BIOS will also tell you if there is an issue with the PC. It does this by looking for all the known devices & makes positive they are still attached to the computer.
If the BIOS detects an issue in the work of the power on self check, it sends a series of beeps to the computer's speaker. These beeps tell the user of what the issue is. As an example, in the event you video card is not working, the BIOS will sense that it's died or is not installed. The BIOS will send a series of beeps to the PC speaker to let you know there is an issue.
      If everything checks out, the BIOS will activate other BIOS chips on different cards installed on the computer. For example: graphics cards often have their own BIOS chip. It next looks for all the parts & peripheral devices that are attached to your computer. The CMOS memory chip stores the information that is used by the BIOS setup & testing routines.
      If everything is working properly, the BIOS will find all the attached input/output devices & sound a single short beep through the speaker & the computer will boot up as usual.

History of BIOS and IDE limits

ATA Specification (for IDE disks) - the 137 GB limit

At most 65536 cylinders (numbered 0-65535), 16 heads (numbered 0-15), 255 sectors/track (numbered 1-255), for a maximum total capacity of 267386880 sectors (of 512 bytes each), that is, 136902082560 bytes (137 GB). In Sept 2001, the first drives larger than this (160 GB Maxtor Diamondmax) appeared.

BIOS Int 13 - the 8.5 GB limit

At most 1024 cylinders (numbered 0-1023), 256 heads (numbered 0-255), 63 sectors/track (numbered 1-63) for a maximum total capacity of 8455716864 bytes (8.5 GB). This is a serious limitation today. It means that DOS cannot use present day huge disks.

The 528 MB limit

If the same values for c,h,s are used for the BIOS Int 13 call and for the IDE disk I/O, then both limitations merge, and can use at most 1024 cylinders, 16 heads, 63 sectors/track, for a maximum total capacity of 528482304 bytes (528MB), the infamous 504 MiB limit for DOS with an elderly BIOS. This started being a controversy around 1993, and people resorted to all kinds of trickery, both in hardware (LBA), in firmware (translating BIOS), and in application (disk managers). The idea of `translation' was invented (1994): a BIOS could use geometry while speaking to the drive, and another, fake, and geometry while speaking to DOS.

The 2.1 GB limit (April 1996)

Some older BIOSes only allocate 12 bits for the field in CMOS RAM that gives the number of cylinders. Consequently, this number can be at most 4095, and only 4095*16*63*512=2113413120 bytes are available. The effect of having a bigger disk would be a hang at boot time. This made disks with geometry 4092/16/63 popular. And still today plenty of giant disk drives come with a jumper to make them appear 4092/16/63. Other BIOSes would not hang but detect a much smaller disk, like 429 MB instead of 2.5 GB.

The 3.2 GB limit

There was a bug in the Phoenix five.03 and five.04 BIOS firmware that would cause the process to lock up in the CMOS setup for drives with a capacity over 3277 MB.

The 4.2 GB limit (Feb 1997)

Simple BIOS translation (ECHS=Extended CHS, sometimes called `Large disk support' or `Large') works by repeatedly doubling the number of heads and halving the number of cylinders shown to DOS, until the number of cylinders is at most 1024. Now DOS and Windows 95 cannot handle 256 heads, and in the common case that the disk reports 16 heads, this means that this easy mechanism only works up to 8192*16*63*512=4227858432 bytes (with a fake geometry with 1024 cylinders, 128 heads, 63 sectors/track). Note that ECHS does not modify the number of sectors per track, so if that is not 63, the limit will be lower.

The 7.9 GB limit

Slightly smarter BIOSes avoid the earlier issue by first adjusting the number of heads to 15 (`revised ECHS'), so that a fake geometry with 240 heads can be obtained, nice for 1024*240*63*512=7927234560 bytes.

             The 8.4 GB limit

Finally, if the BIOS does all it can to make this translation a success, & makes use of 255 heads & 63 sectors/track (`assisted LBA' or `LBA') it may reach 1024*255*63*512=8422686720 bytes, slightly less than the earlier 8.5 GB limit because the geometries with 256 heads must be avoided. (This translation will use for the number of heads the first value H in the sequence 16, 32, 64, 128, 255 for which the total disk capacity fits in 1024*H*63*512, & then computes the number of cylinders C as total capacity divided by (H*63*512).)

The 33.8 GB limit (August 1999)

The next hurdle comes with a size over 33.8 GB. The issue is that with the default 16 heads & 63 sectors/track this corresponds to a variety of cylinders of over 65535, which does not fit in to a short. Plenty of BIOSes could not handle such disks. (See, e.g., Asus upgrades for new flash images that work.) Linux kernels older than five.2.14 / five.3.21 need a patch. See IDE issues with 34+ GB disks below.

The 137 GB limit (Sept 2001)

As mentioned above, the elderly ATA protocol makes use of 16+4+8 = 28 bits to specify the sector number, & hence cannot address over 2^28 sectors. ATA-6 describes an extension that allows the addressing of 2^48 sectors, a million times as much. There is support in recent kernels.

The 2TiB limit

With 32-bit sector numbers, can address 2 TiB. Lots of program will must be rewritten one time disks get larger.

*) Hard drives over 8.4 GB are supposed to document their geometry as 16383/16/63. This in effect means that the `geometry' is obsolete, & the total disk size can no longer be computed from the geometry, but is present in the LBA capacity field returned by the IDENTIFY command. Hard drives over 137.4 GB are supposed to document an LBA capacity of 0xfffffff = 268435455 sectors (137438952960 bytes). Now the actual disk size is present in the new 48-capacity field.

What is BIOS ?

 Stand for basic input/output system, also the built-in software that determines what a computer can do without accessing programs from a disk.

•  The BIOS is usually placed in a ROM chip that comes with the computer (it is often called a ROM BIOS). This ensures that the BIOS will always be available and won't be damaged by disk failures. It also makes it feasible for a computer to boot itself. Because RAM is faster than ROM, though, plenty of computer manufacturers design systems so that the BIOS is copied from ROM to RAM each time the computer is booted. This is known as shadowing. .
• The PC BIOS is standardized, so all PCs are similar at this level (although there's different BIOS versions). Additional DOS functions are usually added through software modules. This means you can upgrade to a newer version of DOS without changing the BIOS.
• Plenty of modern PCs have a flash BIOS, which means that the BIOS has been recorded on a flash memory chip, which can be updated if necessary
• On PCs, the BIOS contains all the code required to control the keyboard,display screen, disk drives, serial communications, and a few miscellaneous functions, and it can handle Plug-and-Play (PnP) devices are known as PnP BIOSes, or PnP-aware BIOSes. These BIOSes are always implemented with flash memory than ROM.

Types of ROM

PROM (Programmable Read Only Memory) is a ROM that can be programmedonce by the programmer, then can not be changed back.

EPROM (Erasble Programmable Read Only Memory) is a ROM that can be erasedwith ultraviolet light (dried with sunlight) and can be programmed back repeatedly.

EEPROM (electrically erasable Programmable Read Only Memory) is a ROM that can be erased electronically and can be programmed back

ROM's Function

As had been described in the past that usually ROM used for storing firmware. On the computer, are often found to store the BIOS. When a computer is turned on, the BIOS can be directly executed quickly, without having to wait for powering the tool storage media in advance as is common in storage devices other than ROM.

Usually, on the other storage media, if executed to read the contents or knowledge, storage media must be turned on first before it is read, which of work requires some time. Things like this do not happen in the ROM.

On the computer (PC) modern BIOS is stored in ROM chips that can be electrically re-writeable known as Flash ROM. That is why the term is more popular than the ROM BIOS.

Definition of ROM

             Read-only memory (ROM) is a class of storage medium used in computers and other electronic devices. Information stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is chiefly used to distribute firmware (software that is closely tied to specifichardware, & unlikely to need frequent updates).

             In its strictest sense, ROM refers only to mask ROM (the oldest type of solid state ROM), which is fabricated with the desired knowledge permanently stored in it, & thus can seldom be modified. Despite the simplicity, speed and economies of scale of mask ROM, field-programmability often make reprogrammable memories more flexible & cheap.

             Usually, on the other storage media, if executed to read the contents or knowledge,storage media must be turned on first before it is read, which of work requires some time. Things like this do not happen in the ROM.

             On the computer (PC) modern BIOS is stored in ROM chips that can be electricallyre-writeable known as Flash ROM. That is why the term flash BIOS is more popular than ROM BIOS.