Received: from PCH.mit.edu (18.7.21.50) by mail.efplus.com (192.168.0.8) with Microsoft SMTP Server (TLS) id 8.3.485.1; Mon, 22 Feb 2021 11:31:46 -0800 Received: from PCH.MIT.EDU (localhost.localdomain [127.0.0.1]) by PCH.mit.edu (8.14.7/8.12.8) with ESMTP id 11MJLnIj020897; Mon, 22 Feb 2021 14:22:45 -0500 Received: from outgoing-exchange-7.mit.edu (OUTGOING-EXCHANGE-7.MIT.EDU [18.9.28.58]) by PCH.mit.edu (8.14.7/8.12.8) with ESMTP id 11MJLlho020894 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 22 Feb 2021 14:21:47 -0500 Received: from w92exedge4.exchange.mit.edu (W92EXEDGE4.EXCHANGE.MIT.EDU [18.7.73.16]) by outgoing-exchange-7.mit.edu (8.14.7/8.12.4) with ESMTP id 11MJLPsj025830 for ; Mon, 22 Feb 2021 14:21:47 -0500 Received: from w92expo21.exchange.mit.edu (18.7.74.75) by w92exedge4.exchange.mit.edu (18.7.73.16) with Microsoft SMTP Server (TLS) id 15.0.1293.2; Mon, 22 Feb 2021 14:21:09 -0500 Received: from oc11exhyb7.exchange.mit.edu (18.9.1.112) by w92expo21.exchange.mit.edu (18.7.74.75) with Microsoft SMTP Server (TLS) id 15.0.1365.1; Mon, 22 Feb 2021 14:21:33 -0500 Received: from NAM11-DM6-obe.outbound.protection.outlook.com (104.47.57.171) by oc11exhyb7.exchange.mit.edu (18.9.1.112) with Microsoft SMTP Server (TLS) id 15.0.1395.4 via Frontend Transport; Mon, 22 Feb 2021 14:21:32 -0500 Received: from BN9PR03CA0785.namprd03.prod.outlook.com (2603:10b6:408:13f::10) by PH0PR01MB6117.prod.exchangelabs.com (2603:10b6:510:9::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3868.31; Mon, 22 Feb 2021 19:21:32 +0000 Received: from BN8NAM11FT032.eop-nam11.prod.protection.outlook.com (2603:10b6:408:13f:cafe::c3) by BN9PR03CA0785.outlook.office365.com (2603:10b6:408:13f::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3868.27 via Frontend Transport; Mon, 22 Feb 2021 19:21:31 +0000 Received: from mail-ej1-f52.google.com (209.85.218.52) by BN8NAM11FT032.mail.protection.outlook.com (10.13.177.88) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3868.27 via Frontend Transport; Mon, 22 Feb 2021 19:21:31 +0000 Received: by mail-ej1-f52.google.com with SMTP id hs11so31196268ejc.1 for ; Mon, 22 Feb 2021 11:21:31 -0800 (PST) From: David C Brown To: Microcontroller discussion list - Public. Sender: "piclist-bounces@mit.edu" Date: Mon, 22 Feb 2021 11:21:31 -0800 Subject: [PIC] Double length decrement Thread-Topic: [PIC] Double length decrement Thread-Index: AdcJUVwbpd+XJB3eSc+mUoZQzSxd5w== Message-ID: List-Help: List-Subscribe: , List-Unsubscribe: , Reply-To: Microcontroller discussion list - Public. Accept-Language: en-US X-MS-Exchange-Organization-AuthAs: Anonymous X-MS-Exchange-Organization-AuthSource: TS500.efplus4.local X-MS-Has-Attach: X-Auto-Response-Suppress: All X-MS-Exchange-Organization-SenderIdResult: Pass X-MS-Exchange-Organization-PRD: mit.edu X-MS-TNEF-Correlator: received-spf: Pass (protection.outlook.com: domain of gmail.com designates 209.85.218.52 as permitted sender) receiver=protection.outlook.com; client-ip=209.85.218.52; helo=mail-ej1-f52.google.com; dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=8mEiwmq/s9cK2ze7hRkJpX0seXoV8tYRs5TGfCGWYL8=; b=gho5xMMamtkGtx06FGWQnD1+tmJritw4g59kiZHTjkBLmSKkh2OzS/qs+ogt0dKjfM qCOlnFG2LCNja8piGoC9uutKd6kLETL480euXn/GeXOnH7pzbws2AOI6+i483MTIR6q5 dvI90ZIJMkWvzcD2lCB9IriuwRS3Dl8glW9ereZ1Mn/sZZTVmiyDD/DFkzMRjIq6ls6y O5h/KQdGkCpFLvwbfeRgo8m76E16XXof2EVEOqjlvNUuh3SVTlsvPZLCBmqo8NDXyJTU LfD21sD8csbiubC1r1g635UK5m6z+D6H28znIY4i/3XdlxBcXr629pgyWB7jOh1URakA KPVA== authentication-results: spf=pass (sender IP is 209.85.218.52) smtp.mailfrom=gmail.com; mit.edu; dkim=pass (signature was verified) header.d=gmail.com; mit.edu; dmarc=pass action=none header.from=gmail.com; errors-to: piclist-bounces@mit.edu list-id: "Microcontroller discussion list - Public." list-post: x-beenthere: piclist@mit.edu x-mailman-version: 2.1.6 x-received: by 2002:a17:906:259a:: with SMTP id m26mr22636347ejb.399.1614021690794; Mon, 22 Feb 2021 11:21:30 -0800 (PST) x-topics: [PIC] x-content-filtered-by: Mailman/MimeDel 2.1.6 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 I am ashamed to admit that I am struggling to do this in a PIC18F88. Subtract 1 from a sixteen bit number and indicate when it goes negative Can anyone spare my blushes? __________________________________________ David C Brown 43 Bings Road Whaley Bridge High Peak Phone: 01663 733236 Derbyshire eMail: dcb.home@gmail.com SK23 7ND web: www.bings-knowle.co.uk/dcb *Sent from my etch-a-sketch* --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .