[Info-vax] History question about ODS-1

[Jon Pinkley]

On Monday, July 29, 2019 at 4:42:56 PM UTC-4, Lee Gleason wrote:
---snip---
>   It looks to be a size problem - apparently VMS 7.3 only supports ODS-1 
> volumes up to a certain size. This is an RA92 ODS-1 disk image, from an RSX 
> system, which is apparently too big for VMS. I'm basing this guess on the
> 
> %INIT-F-LARGECNT, disk too large to be supported
> 
> message I get when I try and INIT an RA92 as ODS-1 using the /STRUCT=1 
> switch.
> 
> --
> Lee K. GLeason N5ZMR
> Control-G Consutants

This document, http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rsx11/Files-11_ODS-1_Spec_Apr81.pdf says on page 29, that ODS-1 volumes are limited to 1,044,480 512 byte blocks, ~ 500MB.  Due to size of storage bitmap.

Whether this was ever increased, I don't know.

You may be able to find an old vax version of lddriver, and create a 500MB virtual disk, then init it.