DecServer 550 chassis

Johnny Billquist bqt at
Mon Oct 19 13:46:56 CDT 2015

On 2015-10-19 20:43, Paul Koning wrote:
>> 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.

The amount of swearwords from TOPS-20 people exceed all others combined, 
in my experience. So if they intended CTERM to be something reasonable 
for TOPS-20 it was an utter failure. :-)

And it's really silly and sad, considering that something like telnet is 
very simple and straight forward, and can be done right on both VMS and 
TOPS-20, and will in the end work much better for people connecting from 
one to the other, than using CTERM...
(I have the same issues with CTERM under RSX. telnet makes so much more 


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