1. What is a (Flash) BIOS ?
Pronounced “bye-ose,” BIOS is an acronym for basic input/output system. The BIOS is built-in software that determines what a computer can do without accessing programs from a disk. On PCs, the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions.
The BIOS is typically placed on 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 will not be damaged by disk failures. It also makes it possible for a computer to boot itself.
Because RAM is faster than ROM, many 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, and should be disabled in the BIOS setup before flashing.
Most modern PCs have a flash BIOS, which means that the BIOS has been recorded on a rewriteable memory chip, which can be updated if necessary.
The PC BIOS is standardized, so all PCs are alike at this level (although there are 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.
PC BIOSes that can handle Plug-and-Play (PnP) devices are known as PnP BIOSes, or PnP-aware BIOSes. These BIOSes are always implemented with flash memory rather than ROM.
2. How do you determine if your system has a Flash Bios chip ?
Take the cover of the computer and look inside. Peel the sticker of the BIOS chip (28 or 32-pin DIP IC with the BIOS brand sticker on it). (source: c’t 2/97/110)
- Am29F010: AMD 5 volt flash ROM
- Am28F010, Am28F010A: AMD 12 volt flash ROM
- AT28C010, AT28MC010, AT29C010, AT29LC010, AT29MC010: Atmel 5 volt flash ROM
- CAT28F010V5, CAT28F010V5I: Catalyst 5 volt flash ROM
- CAT28F010, CAT28F010I: Catalyst 12 volt flash ROM
- 28F010: Fujitsu 12 volt flash ROM or ISSI 12 volt flash ROM
- HN58C1000: Hitachi 5 volt flash ROM
- HN28F101, HN29C010, HN29C010B, HN58C1001, HN58V1001: Hitachi 12 volt flash ROM
- A28F010, 28F001BX-B, 28F001BX-T, 28F010: Intel 12 volt flash ROM
- M5M28F101FP, M5M28F101P, M5M28F101RV, M5M28F101VP: Mitsubishi 12 volt flash ROM
- MX28F1000: MXIC 12 volt flash ROM
- MSM28F101: OKI 12 volt flash ROM
- KM29C010: Samsung 5 volt flash ROM
- DQ28C010, DYM28C010, DQM28C010A: SEEQ 5 volt flash ROM
- DQ47F010, DQ48F010: SEEQ 12 volt flash ROM
- M28F010, M28F1001: SGS-Thomson 12 volt flash ROM
- 28EE011, 29EE010: SST 5 volt flash ROM
- PH29EE010: SST ROM Chip – Flashable
- TMS29F010: Texas-Instr. 5 volt flash ROM
- TMS28F010: Texas-Instr. 12 volt flash ROM
- W29EE011: Winbond 5 volt flash ROM
- W27F010: Winbond 12 volt flash ROM
- X28C010, X28C010I, XM28C010, XM28C010I: XICOR 5 volt flash ROM
- 29LVxxx – 3V Flash memory (rare)
- 28Cxxx – EEPROM, similar to Flash memory
- 27Cxxx – With window. EPROM: read-only, requires programmer to write and UV to erase.
Anything without a Window that doesn’t have a 28 or 29 as the preceding numbers of the part #, is most likely a standard ROM.
3. Do you really need a (Flash) BIOS upgrade ?
OS Support – It’s possible that Windows 95 isn’t configured 100% correctly on a computer with an outdated BIOS. To let Windows 95 fully support Plug ‘n Play you also need a PnP-BIOS. This is a very important reason to update your BIOS.
Large HDD support – All harddisks that are sold today are more then 528 megabyte. To support these harddisks the BIOS must have LBA (Logical Block Addressing) support. When your BIOS doesn’t support LBA and you want to use your new harddisk at full capacity you have to use software drivers that trick the BIOS. With some of these software drivers Windows 95 will load your HD in compatibility mode which means a performance loss.
A third important reason to upgrade your BIOS is to solve bugs. Other reasons are e.g. new settings in your BIOS: Booting from CD-ROM, Boot from SCSI before IDE harddisks,…
There is no guarantee a new BIOS will solve your problems, and flashing can be risky.
4. Where can I download Flash BIOSs ?
Well, start looking at my page. If your motherboard manufacturer isn’t listed on the BIOS Upgrades page then there is big chance they don’t have a web site, or are out of business. Post in our BBS and if it exists, someone will find it for you. (But do your own web search before you post, and let us know what you find out.)
If that fails, contact us and we’ll add your description to the Wanted BIOS page. If you know of any Flash BIOSs not listed on my Flash BIOS page, please let me know.
If you found your Flash BIOS stored on this site, you should first check the Flash BIOS page from the motherboard manufacturer to see if there are any updates. (I can’t check all the sites of motherboard manufacturers daily to see if there are any updates.)
5. What if you don’t know the name of your motherboard ?
The part number of each Award & AMI BIOS usually contains information identifying the chipset it supports, and the manufacturer. This information appears at the bottom of your screen after power on, during memory count up.
Copy down your BIOS id string EXACTLY when it appears on your screen. Better yet, dump it to the printer (Print screen key). The PAUSE key should work at that point, allowing you to read the part number, the BIOS date, and the version.
Unfortunately, in some cases, the manufacturer removes that information. Then your only recourse is to contact the board manufacturer.
Check either the Award or AMI BIOS Numbers page and search for your BIOS number. Partial searches work best, ie: 2A5LDH09C.
If you can’t find it, post a question in our BBS. Before you post, run CTBios 1.5 (written by CT), and put the results in your post. Make sure the full BIOS id string is included. If you have an AMI BIOS you can also try the AMIBIOS Motherboard ID Utility (written by AMI)
If you have an Award BIOS, you can also email AWARD at award888@ms1.hinet.net or support@unicore.com and give them a) version, b) part number and c) release date.
6. How do you flash your BIOS ?
- To flash your BIOS you’ll need a) a flasher, and b) a data-file. The flasher programs the data-file into the BIOS chip.
- Boot to the DOS prompt, either using a CLEAN boot disk or Safe Mode DOS Prompt.
- Type the following at the DOS prompt, where xxx is the name of the BIOS file you downloaded:
awdflash xxx.bin (for Award BIOSs) / amiflash xxx.rom (for AMI BIOSs) / mrflash xxx.bin (for MRBIOSs)
Notes:
- Most flashers will ask you to save the current BIOS. Choose Yes, so that you can always flash back to the original version if you’re having problems with the new one.
- Some manufacturers may use their own utilities to upgrade the BIOS (mostly non-clones)
- Disable the System BIOS Cacheable option in the BIOS before flashing.
- Do NOT flash under Windows or any OS other than plain DOS.
- By using the switch /? (eg. awdflash /?) the flasher will display all available switches.
7. What to do when the Award flasher says: Insufficient memory
- In CMOS Chipset Features Setup, disable every form of caching and shadowing you can find, ie: Video Bios Cacheable. Save and exit.
- Reboot and hit Ctrl+F5,when you see “Windows Starting” (This temporarily prevents Drvspace.bin from loading-making 108K more Memory available.)
- Award 7.x flashers now have a switch /tiny . If you use that switch (eg. awd7xx /tiny newbios.bin) the Award flasher will need less free memory.
