Digital Devices U-CALL Universal Modem Interface

[AtariGeezer]

Anyone ever seen one of these?

 

I have one arriving on Tuesday and was wondering if they use a standard R: handler or what?

 

[+Stephen]

Wow - that's new to me.

[AtariGeezer]

Same here, After buying it, I looked for reviews of it but only saw a couple ads in Antic and Compute! mags...

[Brentarian]

Good find! If I had to guess I would say probably RVerter.

[AtariGeezer]

It arrived today, it's not a RVerter circuit that uses a Max232, but rather all discrete components: transistors, diodes, resistors and capacitors.

I'll draw up a schematic and post when finished...

[AtariGeezer]

Here is the Digital Devices U-Call Schematic that I back engineered...

 

[_The Doctor__]

with some small modification this could well go reliably beyond the 19,200 mark... my only gripe was the lack of dtr and now I know why.... just tied to 5v..grrr

Supra had one for pairing with an AVATEX modem but it was a combination somewhere between this an actual r device... it buffered some.. this also explains something in terms of evolution of the product

[AtariGeezer]

Yep, the PCB has a provision for an additional transistor that ties to the DTR Line, but it's also shared with the TXD circuit so that probably wouldn't fly...

[Kyle22]

I have been saying for a while that R:Verter is the simple, cheap interface. The problem is that it lacks proper control lines. What we need is to use a joystick port to add the missing lines so we can have full flow control.

 

Ideas?

[_The Doctor__]

as you can see this device did have the lines... just not dtr in this version.. though I am certain it could be added... supra had one that did dtr... used the modem with... It worked over sio no weird wires to the joystick port... ri (ring indicate) is really not used by anything at all even back then.. the bbs just looked for the connect message, ring, carrier detect, and dtr to hang up.... in any event, I bet a close look, rework and a capable driver will yield a suitable modern day device that suits the purpose...

[+hunmanik]

Do we have an answer to the original question? What software or type of R: handler would work with the U-CALL? Was it distributed with software?

[AtariGeezer]

It would use a Handler similar to the R-Verter, but not the exact same one. The U-Call uses RI (Ring Indicator) and R-Verter uses RTS.

I'm sure it was it distributed with software to use it...

[+hunmanik]

A couple years back I constructed what I think is a very comprehensive collection of R: handlers, but I don't have anything I can recognize as being for the U-CALL.

 

Another possibility is if it were distributed with a complete communications program with built-in handler. But I don't know of a program like that either.

 

So I'm hoping someone can post or share any original software, or original documentation, that goes with the U-CALL.

[_The Doctor__]

Geezer is correct in order to use it with TurboTwin2000 BBS it loaded a handler of sorts before the BBS... please check your files for the supra version as well... it was in a black half cartridge sized case with one end completely open that was circa 1985 ish give or take...

 

You could access the device directly but that is pretty much like writing your own driver...

Edited June 15, 2017 by _The Doctor__