DECmate II disk image tooling?

Vincent Slyngstad vincent.slyngstad at
Sun Mar 13 10:32:09 CDT 2022

On 3/13/2022 7:57 AM, David Schmidt via cctech wrote:
> Good point about the CP/M disk - actually it is read just fine with
> cpmtools with this diskdef:
> # PRO CP/M RX50 DZ format (Perhaps only 79 tracks should be used?)
> diskdef dec_pro
>    seclen 512
>    tracks 80
>    sectrk 10
>    blocksize 2048
>    maxdir 128
>    skew 2
>    boottrk 2
>    os 2.2
> end
> So I'm left with figuring out how to pull files off of 12-bit OS/{2}78
> disks.

If you can extract the byte stream from the IMD/IMG files (and 
de-interleave them if necessary into logical order), I have tools to 
read the OS/8, COS, etc. file-systems.

The tools want essentially a 16 bit short for each 12 bit word, in 
logical order.  I think this is essentially what you get for the 
"inefficient" 12 bit mode.  I also have tools to unpack some of the 
interlaced 8-bit formats for RX01/RX02, and those tools may be adaptable 
to the RX50.


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