Notes about copying RomWBW format media between device types

["Douglas W. Goodall" <douglas...@mac.com>]

Friends,

It is one of the design goals that block storage devices (not floppies) 
have identical disk formats for IDE, SD,...

I noticed an odd limitation to the use of "Win32 Disk Imager", when 
using it to manipulate these images.

I started with a Memory Technology Inc 2GB Compact Flash digital memory 
card (CF).
It was formatted with MULTIFMT for 200 logical units. There was space 
for more but that was enough for me.

Over time I used approximately the  first 35 logical units for various 
backups and reference copies of
various software, editors, compilers, and utilities, including the 
development area for my apps.

Once the SD adapter on my N8-2312 was working (Thanks Wayne), I wanted 
to copy the contents of the
compact flash chip to an SD chip so I could move my persistent storage 
to the very convenient on-board
SD adapter.

I used "Win32 Disk Imager" to read the contents of the compact flash 
chip, with the intention of writing it back
to the SD chip. When I tried to write the file back to a fresh SanDisk 
CD card 2G, the imager complained there
wasn't enough room on the SD for the image from the CF. In the 
diagnostic error message, it appeared that there
were just a few fewer sectors on the 2GB SD chip than there had been on 
the 2GB CF.

My recourse at this point is to work around it and use a larger chip 
than I need, but which is large enough for the CF
image. It occurs to me I could get around this perhaps by using "dd" on 
a *nix box, and I haven't tried that yet.

This was unexpected, and I wanted to share this experience with you so 
you can consider this before you waste time
over this.

One other thing I want to mention about the workaround is that if I 
attempt to clone this SD back to a CF, it will have
to be nominally larger or the same size as the source SD, which is 
already slightly less than twice the size desired.

We may want collect specifications on CF and SD chips regarding number 
of sectors so we can be more proactive
about choices regarding media size.  Since RomWBW only fully supports 
2GB media at this time, use of a 2GB chip
was efficient and financially sensible.

Douglas Goodall
do...@goodall.com