Info sought about a pocket terminal

[drlegendre .]

Neat item! If you can't turn up any docs.. here's a thought.

Since you'd only need one switch to toggle 110 / 300, that potentially
leaves five for other uses. Not to say they only used one switch for that
setting, maybe their design required two.. but only one is +required+ at a
minimum.

Pretty safe to say that additional switches are used to manually assert /
de-assert various hardware flow control and device / ring detection lines
(CTS, DSR, DCD / RLSD) and/or enable / disable hardware flow control. You
should be able to test for the manual line settings by watching the
appropriate pins with a meter while trying different switches - see which
lines are being pulled high / low.

So how the heck do you operate a one-line terminal, anyway? Does it have a
scroll-back buffer of 5-10 lines? Do you just have to read way, way fast?
;-)

On Sun, Apr 26, 2015 at 9:06 AM, E. Groenenberg <quapla at xs4all.nl> wrote:

>
> Sifting through a box of odds 'n ends I came acros a sort of pocket
> terminal. It's casing is of the earlier models TI wedge calculators
> and has an 8 digit display. Internally there is an inten 8048 processor
> with some support ttl ic's.
> A spiral cable with a Db25 connectors goes out from where normally the
> charger port would have been for the calculators.
> Behind the battery cover (no space for a battery tough) is a disp switch
> block with 6 switches.
>
> It's made by 'G.R. Electronics LTD' wich had 2 addresses,
> one in the UK and one in the USA.
>
> Google did came with an advert of this device ($395 in 1979) and mentiones
> a slectable speed of 110 - 300 baud and requires a 5V at 450mA.
>
> I was wondering if a list member could tell me what the switches are
> supposed to do (besides setting  the speed)
>
> Funny enough, a similar unit was sold recently (item no 220662386232) which
> has a way higher serial (mine has 7786R)
>
>
> --
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> Zeg NEE tegen de 'slimme' meter.
>
>