DecServer 550 chassis

Paul Koning paulkoning at
Mon Oct 19 13:43:30 CDT 2015

> On Oct 19, 2015, at 2:30 PM, Johnny Billquist <bqt at Update.UU.SE> wrote:
> On 2015-10-19 19:42, Paul Koning wrote:
>> ...
>> CTERM was an attempt to wrap a single protocol around the terribly inconsistent semantics of the terminal drivers in all the DEC operating systems, and to export as much as possible to the server end. ...
> An interesting way to describe it.
> I've always looked at CTERM as an RPC service that essentially have all the functions of the VMS terminal driver. Makes it easy to implement in VMS, as you have a 1:1 mapping. Makes it horrible for everyone else, since other systems do not have the same functionality in the terminal driver, and now have to implement all the remote procedure calls of the VMS terminal driver, and somehow map that into how the native terminal driver works...

You can certainly view it as an RPC, and given that Cterm ended up basically doing VMS, looking at it as the RPC version of the VMS terminal driver is reasonably accurate.  But the original version aimed to support both VMS and TOPS-20 as primary clients, and other operating systems as well.  So it was supposed to be an RPC version of the union of all terminal drivers.  Which means that a full CTERM server (as opposed to client) would be hard to do for everyone, even VMS.


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