Half-duplex VT420?

From: Ethan Dicks <erd_6502_at_yahoo.com>
Date: Mon Oct 8 23:14:28 2001

--- Dave McGuire <mcguire_at_neurotica.com> wrote:
> On October 9, Iggy Drougge wrote:
> > But if I have a toasted line driver, wouldn't that strike both inbound
> > and outbound data?

Nope... there's line drivers and line receivers.

> Nope...many RS232 interfaces are built with 1488 driver and 1489
> receiver chips. Nowadays the Maxim MAX232 (and family) chips are
> popular for that sort of thing since they only require +5V...

Depending on the nature of the circuit - Maxim chips are somewhat
expensive. Older ones use external caps and those are comparitively
expensive, too. If you _don't_ have a ready supply of +/-12V, though,
a Maxim chip might be cheaper.

> but I'll bet the VT420 uses 1488/1489 chips.

Since it's a modern DEC terminal, I'll bet it uses 9636/9637 chips. Those
came in with the VT220.

-ethan


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Received on Mon Oct 08 2001 - 23:14:28 BST

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