Resolved Is ReadSpeed.img valid IMG file?

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Dan Stevens

New member
Nov 2, 2020
3
2
Is the Readspeed.img file, hosted at https://www.grc.com/files/readspeed-img.zip valid?

When I try to open it with WinImage I get the error "ReadSpeed.img is not image file".

When I try to boot the img file in VirtualBox I get the error "Missing Operating System".

Am I doing something wrong or is there a fault with the file?
 

PHolder

Well-known member
Sep 16, 2020
627
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Ontario, Canada
I presume it's valid, or it wouldn't have worked for others, and @Steve wouldn't be hosting it. It's probable it is a "floppy image" and not a "cd image" and that is the difference you're experiencing in the tools?
 

millQ

Member
Oct 20, 2020
22
7
Is the Readspeed.img file, hosted at https://www.grc.com/files/readspeed-img.zip valid?

When I try to open it with WinImage I get the error "ReadSpeed.img is not image file".

When I try to boot the img file in VirtualBox I get the error "Missing Operating System".

Am I doing something wrong or is there a fault with the file?
Are you using Linux/macOS?

^
ReadSpeed IMG file
Linux and macOS users, who do not have access to Windows, may download the ReadSpeed IMG file. After unzipping, the Linux 'dd' command, or other image writing utility, can be used to write the filesystem image to any USB stick to create a bootable 8MB DOS filesystem
 
Last edited:

danlock

Well-known member
Sep 30, 2020
132
45
I tried converting the file from .img to .iso using one utility and was told it was not a valid .img file, FWIW.
 

Steve

(as in GRC)
Staff member
Feb 1, 2019
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Southern CA, USA
www.grc.com
Is the Readspeed.img file, hosted at https://www.grc.com/files/readspeed-img.zip valid?

When I try to open it with WinImage I get the error "ReadSpeed.img is not image file".

When I try to boot the img file in VirtualBox I get the error "Missing Operating System".

Am I doing something wrong or is there a fault with the file?
Dan...

Can you explain what it is that you're attempting to do? There's no such thing as an "invalid image file" since any file can declare itself to be an image. In this case, as the ReadSpeed page states, it's simply the "business end" of a bootable 8MB DOS file system. So, if it is "raw copied" to the front of any bootable device — at least 8MB would be best — it will be bootable. This has worked for me and others. ;)
 
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Dan Stevens

New member
Nov 2, 2020
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Dan...

Can you explain what it is that you're attempting to do? There's no such thing as an "invalid image file" since any file can declare itself to be an image. In this case, as the ReadSpeed page states, it's simply the "business end" of a bootable 8MB DOS file system. So, if it is "raw copied" to the front of any bootable device — at least 8MB would be best — it will be bootable. This has worked for me and others. ;)
I'm using YUMI Legacy to create a multi-bootable USB thumb drive. I was able to get SpinRite to boot from the drive via YUMI's boot menu by taking the SpinRite.img file produced by SpinRite.exe and creating a FreeDOS entry in the YUMI setup app and selecting the SpinRite.img. As I understand it, upon at boot time, selecting the 'FreeDOS (SpinRite)' option in the boot menu, YUMI creates an in-memory disk initialised with the img file and boots from it. I thought I'd be able to do the same with the ReadSpeed.img file, however when I try this I get 'Missing Operating System' error.

However, there's no need for disappointment, since I found a different way to make a bootable ReadSpeed image file that works with YUMI:
  1. Using ReadSpeed.exe, format a different USB thumb drive to boot ReadSpeed.
  2. Using WinImage create a blank image file.
  3. Inject the files from the thumb drive into image file.
  4. Set the Boot Sector Properties to match that of SpinRite.img.
  5. In YUMI setup app, create a FreeDOS entry specifying the img file.
  6. Boot from the USB thumb drive and from the YUMI menu select the 'FreeDOS ReadSpeed' option.
If anyone would like this .img file, it's available here: http://danstevens.github.io/ReadSpeed.img
 

Steve

(as in GRC)
Staff member
Feb 1, 2019
351
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Southern CA, USA
www.grc.com
@Dan Stevens : Yeah. The trouble, again, is that there's no clear and clean definition for an "image file." The .IMG file that the SpinRite.exe produces is for a 1.44MB diskette file system — so for a drive with 2 heads, 18 sectors and 80 tracks. So if that is written to anything that is emulating a diskette, it'll boot. But the .IMG file I've posted for ReadSpeed is for an 8MB file system which assumes a modern CHS-to-LBA (pseudo-physical to logical linear) translation. So they are definitely two different beasties, even though that are both definitely file system image formats. :)
 

danlock

Well-known member
Sep 30, 2020
132
45
ok,
What will you do with the ISO?
I was going to put it in the ISOS directory of a multi-boot USB drive I already had to see if it would work. I gave up on that idea pretty quickly and instead used ReadSpeed.exe to create a bootable ReadSpeed on another USB drive.
 

AndreC

Member
Oct 6, 2020
11
1
I'd love to see an image that would work in my multi-boot as well.. I've been using this setup with SpinRite.iso for years.. we need an ISO for ReadSpeed to work the same.