[ale] Parallel & serial port cards?

[Boris Borisov]

Well that's from the internet "... Some USB to RS232 converters use
integrated DC/DC converters to create the appropriate voltage levels for
the RS232 signals, but in very cheap implementations, the +5 Volt voltage
is directly used to drive the output."

On Sun, Nov 15, 2020 at 5:44 PM Boris Borisov <bugyatl at gmail.com> wrote:

> I think these DAC worked only in real time with precise interrupts to give
> you constant bitrate aka real time DOS . I doubt there would be +12/-12V on
> serial port.
>
> On Sun, Nov 15, 2020 at 5:02 PM Sam Rakowski <devnull at iamdevnull.info>
> wrote:
>
>> Somewhat related, I've always wondered (it hasn't been an issue for me
>> *yet*) is whether those USB->RS232 adapters actually swing +/- 12V or they
>> just stick to TTL levels or similar.
>>
>> Also, are there actual USB->parallel port adapters that truly provide a
>> 'normal' parallel port, with each pin able to be controlled like GPIO pins?
>> I'd like to make another one of those cheap 'n' dirty R-ladder "DACs" to
>> enjoy the hi-fi output of the PC speaker for nostalgia's sake.
>> Sent via BlackBerry
>>
>> -----Original Message-----
>> From: Boris Borisov via Ale <ale at ale.org>
>> Sender: "Ale" <ale-bounces at ale.org>Date: Sun, 15 Nov 2020 14:54:18
>> To: Phil Turmel<philip at turmel.org>; Atlanta Linux Enthusiasts<ale at ale.org
>> >
>> Reply-To: Boris Borisov <bugyatl at gmail.com>,
>>  Atlanta Linux Enthusiasts <ale at ale.org>
>> Subject: Re: [ale] Parallel & serial port cards?
>>
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