X-NEWS: eisner vmsnet.pdp-11: 1612 Relay-Version: ANU News - V6.1 08/24/93 VAX/VMS V5.5-2; site eisner Path: eisner!noc.near.net!MathWorks.Com!panix!news.intercon.com!news.pipeline.com!malgudi.oar.net!infinet!n8emr!elektro!sarvax!frog Newsgroups: comp.sys.dec,vmsnet.pdp-11 Subject: RT-11 V5 DU Bootstrap Broken Message-ID: <1994Mar9.063929.3093@sarvax.cmhnet.org> From: frog@sarvax.cmhnet.org (Jeff 'Frog' Campbell) Date: Wed, 9 Mar 1994 06:39:29 GMT Organization: Comp3, Inc. Lines: 16 Xref: eisner comp.sys.dec:10043 vmsnet.pdp-11:1612 This may be a known problem but it just bit me. In working around a CMD MSCP controller bootstrap problem I had to modify the RT-11 V05.05 DU bootstrap code. In examining the block zero boot code I found a stack pop without a prior push. Look at label 40$ just behind label BIOELK. If the controller or disk returns an error in response to a READ command the driver will branch through label 40$ to BINIT. Eventually the READ operation will RETURN to ?. The same problem exists as far back as V05.01. I don't have access to V05.06 kit to see if it's broken as well. The fix is to NOP the TST instruction. -- *** Jeff Campbell N8WXS '76 R75/6 70010,160 frog@sarvax.cmhnet.org ***