OT: Memtest86 - a FLOP!

How would Avast and Memtest86 overlap functions?

A virus scanner and a memory tester??

What are you trying to do?

Virus scanners thrash all available RAM until something breaks?

Who knows....

He should get together with skybuck flying, combine their respective software- and hardware- breaking talents.

--

John Devereux

What are you trying to accomplish? What do you have to work with? What did you try and what happened? Where are you stuck?

If you want a bootable memory tester, try Memtest86+ 4.20 USB version at: or Memtest86 4.10 at: Just follow the USB install instructions. You'll also find memtest on most Linux LiveCD's as one of the boot menu choices.

If you're having problems making a bootable CD from an ISO image, see the above URLs for instructions.

Umm... Avast is not a memory tester.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Find it in the grub (or BURG) subdirectory.

It is a Linux binary, not a DOS executable.

Take that source and write your own. Not much to it.

Use the USB flash drive version. It's dead simple.

I've used memtest86 for years with floppy (before they became extinct), CD and now flash drives. At the moment, I have the flash drive version installed on an 8MB SD card that came with my old camera. I use it with a card reader all the time when troubleshooting computers.

memtest86 doesn't use an OS. It expects to be executed directly by either the BIOS or a bootloader (which is why it's often bundled with GRUB or LILO).

It works fine off a floppy; you just need to "raw write" it directly to a floppy disk (copying it to a floppy containing a filesystem won't work). With Linux, you can use e.g. "dd if=memtest86 of=/dev/fd0"; for Windows there's "RawWrite".

A "floppy image" would just be the memtest86 binary, padded to 1440 kiB. Any tool which can write such an image can also write an unpadded memtest86 binary.

A search on my computer found no such a thing as "rawwrite". Also, if that program did an EXACT copy to the floppy, there would be some serious problems:

1) the ISO file starts with some kind of a header that does not belong ("SYSLINUX" for one). 2) the file length is quite a bit longer than a standard 1.44K floppy.

What if you start by reading the manual... I have used memtest86+ before and it is extremely simple. Are you looking at the latest version of memtest86? IIRC there are two versions one of which is no longer supported.

--
Failure does not prove something is impossible, failure simply 
indicates you are not using the right tools... 
nico@nctdevpuntnl (punt=.) 
--------------------------------------------------------------

Not "rawwrite"; RAWRITE.EXE. It's included with the floppy versions of MemTest86+ 4.20 and MemTest86 ver.

3.5x

I had trouble making a bootable USB stick for MemTest86 under Windows, so I ran the USB stick creator for MemTest86+ and substituted the MemTest86 binary file in the USB stick by renaming it MT86PLUS. (no extension). Sometimes MemTest86 and MemTest86+ give different test results, despite using the same test methods.

You could instead create a CD or DVD from UBCD.com (Ultimate Boot CD), which includes MemTest86 and MemTest86+, along with several other diagnostics.

I think both MemTest86 and MemTest86+ went without official updates since early 2011, but this January MemTest86 ver. 4.10 was released, and MemTest86+ ver. 5.00 beta has been out for almost a year, in several versions (latest dated today). I tried an older 5.00 beta and it worked fine with an old BioStar Intel G41-M7 motherboard but showed loads of probably false errors with an MSI Intel Z68-G43 (G3). I'm pretty sure they're false errors because I didn't use A-1 finest quality you betcha memory with useless heatsinks hiding junk or overclocked DRAM chips but instead used Samsung modules.

with an MSI Intel Z68-G43 (G3).

overclocked DRAM chips but instead used Samsung modules.

If you already know that your Samsung memory is flawless, what use is the test? And what do you mean by a false error in a memory test? ISTM that either the program is junk or the memory is broken.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Memtest will also show problems with DMA controllers and various motherboard related issues. The RAM can be fine, but the motherboard defective. There are also RAM brands and motherboard combinations that don't seem to get along. I use it as an overnight burnin test. While RAM errors are the most common, I still find plenty of odd motherboard errors, especially when badly soldered BGA chips are involved.

Agreed. In my experience, when MEMTEST86+ shows an error, there's something wrong. I have never seen a "false error". It's much like the tube testers of bygone days. When the tester says it's bad, it's definitely bad. When the tube tester says it's good, it may still be bad. The difficult part with MEMTEST86+ is decoding the display to determine where the error is located.

Another possible complexication is testing video RAM. This appears in the memory map, but because it appears in a window, it is not tested by MEMTEST86+. For video, I use the free DX9 version of 3DMark: for both testing and benchmarking. It's a 600KByte download that expands to about 1.5GB when installed. However, that's not important with todays oversized hard disks.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Not so.

The CD versions are ISO format (ISO9660 image).

The floppy versions are standard disk image (img) files.

as all one of 7 supposed

I had no trouble making CDs from both Windows and linux versions. The Win and linux versions are, in fact, identical. Both successfully booted.

CDs made using XCDRoast frontend to mkisofs and cdwrite.

You need to set your CD writer *NOT* to pad tracks, and (preferably) to write disk-at-once mode. The CD won't boot with padded tracks.

CD info from written CD:

# isoinfo -d -dev=0,0 CD-ROM is in ISO 9660 format System id: LINUX Volume id: CDROM Volume set id: Publisher id: Data preparer id: Application id: GENISOIMAGE ISO 9660/HFS FILESYSTEM CREATOR (C) 1993 E.YOUNGDALE (C) 1997-2006 J.PEARSON/J.SCHILLING (C) 2006-2007 CDRKIT TEAM Copyright File id: Abstract File id: Bibliographic File id: Volume set size is: 1 Volume set sequence number is: 1 Logical block size is: 2048 Volume size is: 584 El Torito VD version 1 found, boot catalog is in sector 26 NO Joliet present NO Rock Ridge present Eltorito validation header: Hid 1 Arch 0 (x86) ID '' Key 55 AA Eltorito defaultboot header: Bootid 88 (bootable) Boot media 0 (No Emulation Boot) Load segment 0 Sys type 0 Nsect 4 Bootoff 1B 27

Both floppy images use syslinux boot. Both linux and Win floppies worked fine. The Win one actually boots a linux system.

You need a utility like dd (linux) or rawrite (Win), to make floppies from an image, since it needs a block-by block copy.

: HAHAR!, Avast there!

--
"For a successful technology, reality must take precedence  
over public relations, for nature cannot be fooled." 
                                       (Richard Feynman)

Same as any Windows computer. It's not a provided utility.

It's readily available on the 'net. Used to be included with just about every linux distribution CD.

It's needed only on Windows, because that OS doesn't include raw disk read/write.

The ISO file is a ***CD*** image (ISO9660 filesystem). NOT a floppy image. You need to download the floppy image from the same site, and rawrite it to a HD floppy.

Syslinux does belong, it's one of several linux boot systems.

1.44K floppy.

That's because of the above. The proper floppy image is the correct size to fit. (FAT12 filesystem).

The CD images include extra files, a full manual. That's why they're bigger.

I think you need to read the quite explicit installation notes provided on the memtest site.

An understanding of how different filesystems are organized at the hardware level will help.

--
"For a successful technology, reality must take precedence  
over public relations, for nature cannot be fooled." 
                                       (Richard Feynman)

an MSI Intel Z68-G43 (G3).

overclocked DRAM chips but instead used Samsung modules.

I have been using Kingston modules for years and usually they are excellent but there can always be a module which passed QC but isn't just right. One machine I got started to act funny under high loads and one of memory modules turned out to be the culprit (*). If memtest shows your memory is faulty, IT IS FAULTY especially when memtest shows loads of errors. You just may not notice it during normal use. Memory faults can depend on the order of how memory is accessed, read or writting and even certain bit patterns. Why do you think it takes Memtest hours to go through one loop? The memory module I'm talking about only showed 2 errors but those where enough to mess things up every now and then.

(*) I send the module back and got a brand new one.

--
Failure does not prove something is impossible, failure simply 
indicates you are not using the right tools... 
nico@nctdevpuntnl (punt=.) 
--------------------------------------------------------------

I got a new motherboard and wanted to test it, and a memory diagnostic was the easiest way. I tried 2 versions of MemTest86+, 4.20 and 5.00b1. 4.20 found no errors with that Samsung RAM in 2 very different motherboards, while

5.00b1 said the same RAM had tons of errors with the new motherboard. Other people have reported false positives with 5.00b, and the author admits them:

There is a memory tester on the installation disk of most linux distributions. You can do this from a memory card or thumbdrive.

Go to Costco and buy a new computer. You are wasting time trying to figure this out.

Michael

and MemTest86+ give different test results, despite using the same test methods.

Got that,made the floppy, all computers pass.