MirrorRepos/RomWBW
1
0
Fork 1
mirror of https://github.com/wwarthen/RomWBW.git synced 2026-02-06 22:43:15 -06:00
Code Issues Projects Releases Wiki Activity

Enhance Writing Hard Disk Slices (Discussion #457)

Browse Source 
Per discussion #457 with Hubert Hirsch, I have attempted to enhance the Writing Hard Disk Slices section of the User Guide.
This commit is contained in:
Wayne Warthen
2024-12-01 14:32:51 -08:00
parent 6c96afcb5a
commit b032694e01
6 changed files with 34 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
Source/Doc/UserGuide.md
View File

@@ -2337,12 +2337,21 @@ survive re-imaging, you **must** follow these rules:
This section covers techniques to copy partial images onto pre-existing media,
in effect performing a selective slice copy. These techniques currently **only** apply to
hd1k formatted media, which has a convienient 1MB size metric.
However adapting to hd512 is possible.
hd1k formatted media, which has a convenient 1MB size metric.
However adapting to hd512 is possible, but left to the user.
On Linux/MacOS the `dd` command can be used to write data in a controlled manner.
The `dd` command supports options to define precisly souce
and destination offsets and sizes to copy.
Although Windows does not have a native `dd` command, there are multiple
options for installing it including [MSYS2](https://www.msys2.org/),
[CygWin](https://www.cygwin.com/),
and [dd for Windows](http://www.chrysocome.net/dd).
**WARNING**: The `dd` command is a low-level utility that writes
directly to raw disk sectors with almost no safety checks. It is very
easy to corrupt a disk if this tool is used incorrectly.
The `dd` command supports options to define precisely source
and destination offsets and sizes to copy.
From the documentation of `dd` the following options are important.
```
@@ -2414,6 +2423,27 @@ and 1 is the size of the partition table im megabytes.
Thus we are skipping 6 slices (in the combo image)
and writing to the 7th slice.
#### Example 3 : Copy image using partition
In the previous examples, the hard disk is addressed as a raw disk
device and we took steps to calculate the assumed start of the RomWBW
partition. However, as long as the hd1k format is in use, it is
also possible to just point `dd` directly to the partition itself.
To do this, you must first determine the name that your operating
system is using for the desired partition. Frequently, partitions
are named by simply adding a number after the name of the hard disk
device. For example, if the hard disk is /dev/sdg, the first
partition is frequently /dev/sdg1 or /dev/sdgp1.
Taking advantage of this, it is safer and easier to calculate the
offset of a slice within the partition. It is simply the slice
number \* 8MB. Example 2 above, could now be performed as:
```
Binary % sudo dd if=hd1k_games.img of=/dev/sdg1 seek=48 bs=1M
```
# Operating Systems
One of the primary goals of RomWBW is to expose a set of generic