There a little app that can create ramdisks from images - but I'm not sure if this would work from ISO files because I haven't had much time to try and know very little about ISO data.
In case, the author seems quite open to suggestions, and perhaps he wouldn't mind adding support for gzipped ISO and NRG files wich then could be edited or copied to your USB drive, just a wild idea..
Here's the readme.txt:
SHSUFDRV v1.02
SHSURDRV v1.11
Copyright 2005 Jason Hood
Freeware.
===========
Description
===========
A floppy or hard disk image driver and RAM drive. SHSUFDRV works dir-
ectly with image files; SHSURDRV copies the image into memory, and/or
creates a new drive.
=====
Usage
=====
Run the appropriate program with the name of one or more image files, or
the size of one or more RAM drives. If the images are acceptable, each
image/drive will be assigned a drive letter.
-------
Options
-------
/F specify image file name
/W images are writable (SHSUFDRV)
/D specify RAM drive parameters (SHSURDRV)
/R reserve memory (SHSURDRV)
/T top of memory (SHSURDRV)
/C control memory usage (SHSURDRV)
/V display memory usage
/U unload
/Q quiet
/F - File name
This "option" is required (for SHSUFDRV). It's complete syntax is:
[/F[:][?]]filename[,drive]
where FILENAME is the raw disk image and DRIVE is the drive letter to
assign it. The question mark indicates this image should be ignored if
it's invalid (rather than refusing to install). The image is tested for
validity by reading a part of it to see if it looks like a normal disk.
If no drive is specified the first available will be used (note: the
drive letters assigned to subsequent images will always be higher than
those assigned to previous images). SHSUFDRV will leave the file open,
so it should not be moved whilst it is active. SHSURDRV will accept
images compressed by gzip. It will also allow the filename to be an
existing drive, which will then be mirrored to memory; in this case
filename is optional and will be taken as A: if absent. Only drives up
to 32MiB can be mirrored in this manner.
/W - Writable
By default images are not writable, due to problems I had in getting
write to actually work. If you'd like to give it a go, use this option,
but be warned: image and "host" (the drive the image is on) corruption
may occur. To test it, use SHSURDRV to make a RAM drive, copy the image
to that, then use SHSUFDRV on the copy. If you still want some images
to be read-only, make the file itself read-only.
/D - RAM Drive
Create a RAM drive of a specified size. The complete syntax is:
[/D][size][Ssectors][Ccluster][Dentries][Ffats][$[label],][drive]]
although a colon (':') can separate each parameter from its value and
each parameter can be separated by a comma, not just the label. Apart
from SIZE the parameters can be in any order.
SIZE is the amount of free space to give the drive. It can be suffixed
with 'K' to use kibibytes (1024 bytes) or 'M' to use mebibytes (1048576
bytes). The size will be rounded up to a multiple of the cluster size.
If present, it is not necessary to use "/D" (a parameter that starts
with a digit will be assumed "/D", otherwise "/F"). Certain sizes are
used as a predefined floppy format, please use "/?S" to see the list.
SECTORS specifies the exact number of sectors for the drive. If both
SIZE and SECTORS are present, the last used will take effect. The
default is 4101, which is just under 2MiB.
CLUSTER is the cluster size to use, in kibibytes. This value must be a
power of two (ie. 0 = 512 bytes, 1, 2, 4, 8, 16, 32 or 64); any other
value is rounded up to the next, but no higher than 64. The default is
4096 bytes.
ENTRIES is the number of root directory entries. This value will be
rounded up to a multiple of 16. The default is 64.
FATS is the number of file allocation tables. The default is 1 and 2 is
the only other allowed value.
LABEL is the volume label to give the drive. The default is "SHSURDRV".
DRIVE is the drive letter to assign. See /F.
/R - Reserve memory
This option will allocate memory before any drives, then release it upon
exit. It is only necessary in order for Windows to start (when drives
exceed more than 14MiB in total). The default is 4 (kibibytes).
/T - Top of memory
This option will locate each drive at the end of XMS memory, as a more
flexible alternative to /R.
/C - Control memory usage
By default SHSURDRV will automatically relocate itself high. This op-
tion will keep it in conventional memory. Alternatively, if it is al-
ready loaded high, it will automatically relocate into low memory; this
option will then keep it high.
/V - Memory usage
When this option is used at install (it's ignored otherwise), a summary
of the memory usage is given. The summary includes:
Static code and variables
Dynamic data for each image, plus paragraph rounding
SDA swappable data area (to use DOS within DOS)
Total overall memory usage
XMS kibibytes (1024 bytes) or mebibytes (1048576 bytes)
of XMS memory allocated
SDA is used by SHSUFDRV; XMS by SHSURDRV.
/U - Unload
Removes the program from the device driver chain, SHSUFDRV closes its
files, and frees its memory. It is possible to load each program mult-
iple times, in which case only the latest will be removed.
/Q - Quiet
Use this option to prevent the display of the sign-on banner. If used
twice (ie. /QQ), no display will be output at all.
=====
DRVON
=====
The new drives cannot be formatted, but if you try anyway FORMAT (from
MS-DOS) will disable the drive. DRVON can be used to enable the drive -
just run it with the drive letter. It's very simple, so the letter must
be the second character (the separating space counts as the first).
=======
Windows
=======
SHSUFDRV will not work with Win9X; Win3 is fine.
RAM drives greater than 64MiB will not be accessible after starting Win-
dows (Win9X denies access; Win3 just stuffs up).
NT/2K/XP users can use FileDisk (floppy images) or Virtual Floppy Drive/
Disk Driver (floppy/hard disk images, respectively):
http://www.acc.umu.se/~bosse/
http://chitchat.at.i...k.co.jp/vmware/
=========
Exit Code
=========
0 Uninstalled, help displayed
1-32 First drive letter assigned (A: = 1)
255 Not installed, not uninstalled
========
Examples
========
shsurdrv 8192K,Q:
Create a RAM drive that has 8MiB free and access it at Q:.
shsurdrv /f b:,y
Mirror A: to the first available drive letter (which will be returned in
ERRORLEVEL) and mirror B: to Y:.
shsurdrv 1680c1d16m /d:1680,c:2,d:16,s:
Create DMF 1024 and DMF 2048 drives at M: and S:.
=========
Compiling
=========
I have used NASM 0.98.39. Due to my heavy use of the NASM preprocessor,
a 32-bit version is required, with about 6MB of free memory (to avoid
paging). I think version .36 may compile, but not before that. Please
see the MAKEFILE.
There's no need to tell me about UPX, but feel free to use it yourself.
Gzip decompression used by SHSURDRV is from a modified zlib 1.2.3. The
compiled library is supplied, so zlib is not needed, unless you want to
use a different compiler or upgrade to a new version. My modifications
to zlib are in the SHSUCDRD.TXT patch file (apply with -p1). It's
designed for Borland; other compilers may require modification (to
SHSURDRV, as well).
=====
Files
=====
The following files are included in the package:
README.TXT This file
SHSUFDRV.EXE Image file driver (386+)
SHSURDRV.EXE Image file in memory driver, RAM drive (386+)
SHFDRV86.EXE Image file driver (286+)
SHRDRV86.EXE Image file in memory driver, RAM drive (286+)
DRVON.COM Enable a drive
SHSUFDRV.NSM NASM source code for SHSUFDRV
SHSURDRV.NSM NASM source code for SHSURDRV
DRVON.NSM NASM source code for DRVON
NASM.MAC General purpose NASM macros
MAKEFILE (Borland) Makefile
ZLIBCDRD.LIB Library used by SHSURDRV to decompress images
ZLIBCDRD.TXT Patches to zlib 1.2.3 to generate above
=======
History
=======
Legend: + added, - bug-fixed, * changed.
SHSUFDRV v1.02, SHSURDRV v1.11 - 21 December, 2005:
* always use F8 as the media byte (for DV/X File Manager)
SHSUFDRV:
* prevent error on partial images (which have no unused sectors), but
actual read errors may not be found
SHSURDRV:
- incorrectly restored UMB state
* default to 4096-byte cluster; C0 will select 512-byte cluster
SHSUFDRV v1.01, SHSURDRV v1.10 - 14 October, 2005:
- prevent the same drive being assigned more than once
* allow drive letter to be followed by colon
SHSURDRV:
* allow ':' to separate drive parameters
+ F parameter to control number of FATs
+ predefined floppy formats
+ /T to allocate at top of XMS
+ mirror drives
* upgraded zlib to 1.2.3
=======
Contact
=======
mailto:jadoxa@yahoo.com.au
http://shsufdrv.adoxa.cjb.net/
Jason Hood
11 Buckle Street
North Rockhampton
Qld 4701
Australia
==============================
Jason Hood, 21 December, 2005.
