Re: [Simh] Way out idea for simh

[skyvis]

That is what I meant by support. However not all OS's allow you to have a drive that is not part of the file system. Some OS's allow you to gain access to a drive, many don't. Some like IBSYS don't even have the concept of a file system. For CDC COS and Scope the disk basically was a tape image. The OS kept the directory in core. At boot in case of Scope it determined the available tracks by scanning the disk. COS did not have the concept of a disk boot. Every boot reloaded the system. B5500 MCP also operated similar to Scope.


------- Original Message -------
On 4/20/2016 3:14 PM Paul Koning wrote:


> On Apr 20, 2016, at 3:08 PM, sky...@sky-visions.com wrote:

>

> OS's don't support foreign file systems. What they do is provide the ability to access a drive that does not have what they believe to be a valid file system.



Not necessarily. RSTS does in the lates t versions, but not in early versions. For example, RSTS V4A has no raw disk API, and gives you no access to any disk except via the RSTS file system. The same goes for some other operating systems; I don't know of raw disk access on CDC NOS either, for example. (Well, not unless you write a PPU program; if you don't mind doing that, the job is easy.)



paul







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Richard Cornwell
sky...@sky-visions.com
http://sky-visions.com
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