3270 controller simulation

Dave Wade dave.g4ugm at gmail.com
Mon Nov 18 11:38:33 CST 2019

> -----Original Message-----
> From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of Grant Taylor via
> cctalk
> Sent: 18 November 2019 17:16
> To: cctalk at classiccmp.org
> Subject: Re: 3270 controller simulation
> On 11/18/19 9:45 AM, Al Kossow via cctalk wrote:
> > …people have gone Cisco to 3174 to get coax terminals talking to
> > Hercules. I believe Guy S., Dave W. and Jay W. have done this.
> Please confirm if it is DLSw between the Cisco and OS running in Hercules?

I go TN3270 from the 3174 -> Hercules so the screens look like local screens to the OS. This is how most folks have done it.
It needs a big(ish) 3174 and the C6.3 or 6.4 microcode.

As MVS 3.8J does not understand DLSw (it has no TCP) Matt unpicks the DLSw in Hercules so MVS sees (I think) an SDLC connected 3174.

> Sorry for being obtuse.  There are a LOT of different things in IBM networking,
> compounded by other vendors, and I want to make sure I'm tracking properly.
> Particularly as this is something I'd like to reproduce for similar reasons.

You are not being obtuse. IBM networking covers so many options its not true.

> > I have the parts to do either token ring or ethernet on a 3174, and
> > just got probably one of the last 1174s in the world with ethernet
> > (but no docs)
> Would you please clarify if you have the "Local" or "Remote" 3174?

I think TN3270 connected screens usually look like they are "local"....

> Can "Local" and / or "Remote" 3174s be converted to the other end of the link?
> I ask because I think most "Local" 3174s expect the host to be channel attached.
> Don't they?

Define "most" and "when". I have 4 x 3174s plus the guts of two more. None have channel interfaces.
The first three I bought years ago had token ring interfaces and serial interfaces which I think can be bi-sync or SDLC.
Two of the others have token ring, and one has ethernet. I think many connected over token ring...

> > One of my projects is to try to get something similar going that is
> > open-source which is why I was interested in ajk's arduino project
> --
> Grant. . . .
> unix || die

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