From: krewat at kilonet.net (Arthur Krewat)
Subject: [COFF] 52-pin D-Sub?
Date: Fri, 28 Feb 2020 11:35:04 -0500 [thread overview]
Message-ID: <6a44c9e7-1e7b-bd0e-df1c-6e2208e8b780@kilonet.net> (raw)
In-Reply-To: <CAC20D2Or=9DnR287GottTO=1hnZyH4F6TLyipHhkqtepquKVdQ@mail.gmail.com>
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On 2/28/2020 9:11 AM, Clem Cole wrote:
>
> [1] The original PC/AT used the NS8250 UART with no input buffering,
> which went through a couple of generations, eventually begat the *550
> version and had I think an 8 character input buffer. But IIRC none of
> them had hardware flow control. I forget the # now, Moto made a nice
> dual UART with 16 chars of input buffering, that many of us on Unix
> workstation business used, but when we moved to BSD 386 and Linux, we
> were stuck with PC hardware, which had a particularly hard time with
> things like the Trailblazer (which was the modem of choice for UUCP).
>
I ran a BBS for a few years back in the early 90's, and used a 486DX2-66
as my "front-end" to a Sun SPARC-IPC USENET setup. Using two V.34 and
one Worldblazer, running them at 38,400 baud, and taking advantage of
compression, it ran 100% download, 100% upload, or a combination across
three modems without even showing much load at all. It could have easily
taken more if I had the physical space (and the IRQs) on the ISA bus to
add more serial ports. Of course, the interrupt coalescing of the
16550's helped a lot. And I don't know what the saturation point was...
That was on x86 SVR4.2 (Consensys), using a shareware 16550 driver of
the time. The Worldblazer talked to a Trailblazer at Motorola for my
USENET feed and used G protocol, acceleration built into the Telebits.
8250's and 16540's were horrible. Much like DZ11's, eh? ;)
art k.
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next prev parent reply other threads:[~2020-02-28 16:35 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-27 23:37 athornton
2020-02-28 0:04 ` dave
2020-02-28 1:37 ` stewart
2020-02-28 2:12 ` athornton
2020-02-28 4:12 ` dave
2020-02-28 4:18 ` dave
2020-02-28 14:11 ` clemc
2020-02-28 14:34 ` athornton
2020-02-28 21:23 ` dave
2020-02-28 16:35 ` krewat [this message]
2020-02-28 21:28 ` dave
2020-02-28 21:44 ` clemc
2020-02-28 21:58 ` dave
2020-02-28 22:20 ` clemc
2020-02-28 23:22 ` pechter
2020-02-29 13:12 ` emu
2020-02-29 15:45 ` krewat
2020-02-29 15:49 ` clemc
2020-02-28 22:38 ` pechter
2020-02-28 22:05 ` drb
2020-02-28 22:28 ` clemc
2020-02-28 22:26 ` pechter
2020-02-28 22:36 ` clemc
2020-02-28 23:40 ` pechter
2020-02-29 16:52 ` clemc
2020-02-28 23:54 ` pechter
2020-02-29 9:59 rudi.j.blom
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