From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.2 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,DKIM_VALID_EF,MAILING_LIST_MULTI,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: from minnie.tuhs.org (minnie.tuhs.org [50.116.15.146]) by inbox.vuxu.org (Postfix) with ESMTP id 203712ABB5 for ; Mon, 18 Mar 2024 21:22:18 +0100 (CET) Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id D174C427A7; Tue, 19 Mar 2024 06:22:14 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tuhs.org; s=dkim; t=1710793335; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-owner:list-unsubscribe:list-subscribe:list-post; bh=skS/XiIYAGlxzbUrDCZvQMT/UfazzBoMpHIHqTXqIcs=; b=6xWOJewGZ1y6fZKXXCxaIPndmChZPBbSMPuiRwxjaKsozCnTylal9zkM8qIkLWL1pMS/ca T/3DUPADMe5SGX2bTxuXEU2i622Dk6EuMZGTRVH8z+1bDJ2g7lcCT6W2psRw+sh/pHSblp mNcHmckWormwyhrsY1YZlVN93/hgMYs= Received: from mail-40135.protonmail.ch (mail-40135.protonmail.ch [185.70.40.135]) by minnie.tuhs.org (Postfix) with ESMTPS id 3FAA542704 for ; Tue, 19 Mar 2024 06:22:11 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1710793328; x=1711052528; bh=skS/XiIYAGlxzbUrDCZvQMT/UfazzBoMpHIHqTXqIcs=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=PVHKjYGDrpaDY0493JtYAnoUFYl1w8OZYKUh4qWKdOA3FQQazq6eeM/RZPVKWhGDt 5lmBNBGr7ABMV5s4lqRM0VZqbe+Cle6xDELSMtV7s3fVO/wvTEntsA6e5vq6dqQ+Df Ri1rVsFS86hGQpeWhFPJs7Cl72/dMA2oZUjnOXGiwgAJ2vjXvX7t1Nljq7nJ5Ew0f1 du8FR6YeHdWI3LLPF1V0TQTjc/K/Tq4oe13jh15iCTH4jijgeOSKvOz/LKx/7NK5CF sPRRgVn1wf2GL8ieo3wJe3OsdbLfM2cuz8DEDTOC48ZREvCvb6FG9qoSlTXkC8UCN0 i8NYaas8ALb1g== Date: Mon, 18 Mar 2024 20:21:33 +0000 To: Ron Natalie Message-ID: In-Reply-To: References: <20240318152039.GN13814@mcvoy.com> Feedback-ID: 35591162:user:proton MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Message-ID-Hash: XAQXSYW2QSWRQLIZ3D2DU5XBJA6W2MWT X-Message-ID-Hash: XAQXSYW2QSWRQLIZ3D2DU5XBJA6W2MWT X-MailFrom: segaloco@protonmail.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: The Eunuchs Hysterical Society X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Of /dev/tty8 List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: segaloco via TUHS Reply-To: segaloco On Monday, March 18th, 2024 at 1:08 PM, Ron Natalie wr= ote: > The other problem with the DZ is it was one interrupt per character if I > recall. > Thte DH you could get multiple (output) characters per interrupt. > Greatly decreased the load on the system. >=20 > I do remember the KL kernel prints were not interrupt driven so the > system pretty much froze while the kernel printfs were being output. > There was a comment on the code saying this was =E2=80=9CNot for idle chi= t > chat.=E2=80=9D Yep, synchronous code that writes a character at a time to the transmit reg= ister then spins on a status bit awaiting transmit complete, or something l= ike that. I adapted the V6 kernel printf to a RISC-V board I was working o= n the past year to have a trustworthy print mechanism, only caveat being th= e transmitter status register was a dirty filthy liar and wouldn't flip the= bit on transmit, so just had to put a delay, which it turns out all of the= BSDs currently also do for Ti 16550-family UARTs as well. - Matt G.