The Unix Heritage Society mailing list
 help / color / mirror / Atom feed
From: Roderick Bartlett via TUHS <tuhs@tuhs.org>
To: Steve Simon <steve@quintile.net>
Cc: tuhs@tuhs.org
Subject: [TUHS] Re: UNIX "Machine Layer"
Date: Mon, 1 May 2023 21:15:48 -0400	[thread overview]
Message-ID: <2B6C7969-FF99-4693-A3E8-22813E6ECF41@mac.com> (raw)
In-Reply-To: <B72AC0F4-F067-4D8B-9FF5-C5BFB0726D5A@quintile.net>

I believe the async lines were connected to I/O boards in the Front End Processor, AKA the Datanet 66xx.  I don't recall having to change baud rates that way but we did have to do periodic FCOs (field change orders) which required wiring changes and occasional chip changes to correct bugs.  I've still got my hand wire wrap tool somewhere but it hasn't been used in at least 30 years.

 - Rod

> On May 1, 2023, at 2:12 PM, Steve Simon <steve@quintile.net> wrote:
> 
> 
> “soldering iron…”
> 
> i do remember the fun of changing the baud rate of an async line on the Honeywell level 66 mainframe at college. This required shutting the whole machine down, removing one of the cards, and the (very careful) use of a wire wrap tool.
> 
> -Steve
> 

      reply	other threads:[~2023-05-02  1:16 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-01 18:11 Steve Simon
2023-05-02  1:15 ` Roderick Bartlett via TUHS [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=2B6C7969-FF99-4693-A3E8-22813E6ECF41@mac.com \
    --to=tuhs@tuhs.org \
    --cc=norwayjose@mac.com \
    --cc=steve@quintile.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).