Mounting ULTRIX CDROMs on Linux

[Christian Groessler]

More top-post alert! :-)


IIRC I had burned the Ultrix CD "normally" (means without fiddling with 
block size, so not 512), but changed the block size to 512 for booting 
it. IIRC #2, burning was done on another drive, not the Plextor.


regards,
chris


On 5/20/21 11:26 PM, Jonathan Stone wrote:
>
> [[ apologies for top-post: Y! issue ]]
>
> I know that to be bootable on DECstation/VAX/early Alpha, CD-ROMs 
> needs to be jumpered to 512-byte blocks. Like RRD4x.
>
> Does the burning CD write need to be jumpered to 512-bytes? Or can one 
> write on a "normal" CD burner, then read on a 512-byte-block CD-ROM ? 
> If the former, I guess I'll have to find an old, 512-byte-block 
> jumperable SCSI CD burner.
> On Thursday, May 20, 2021, 02:15:39 PM PDT, Christian Groessler via 
> cctalk <cctalk at classiccmp.org> wrote:
>
>
> On 5/20/21 11:05 PM, Jonathan Stone via cctalk wrote:
> >  MacOS (Mojave) can mount an image read from a 512-byte UFS CD.
> >
> > What does one have to do (Linux, MacOS, *BSD) to write such an image 
> to the CD with 512-byte blocks, so it can be read by a DEC boot-ROM?
>
>
> I think that's a property of the CD drive, not the disk itself.
>
> I've got a Plextor CD writer which can be jumpered between 2048 and 512
>
> byte blocks.
>
>
> I was able to boot the Ultrix installation CD (MIPS) on a DECServer.
>
> regards,
> chris
>
>
>