Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!mit-eddie!ll-xn!ames!ucbcad!ucbvax!hoser.berkeley.edu!bryce From: bryce@hoser.berkeley.edu (Bryce Nesbitt) Newsgroups: comp.sys.cbm Subject: 1541C ROM technical question (and vs. 1581) Message-ID: <22080@ucbvax.BERKELEY.EDU> Date: Sun, 6-Dec-87 19:28:41 EST Article-I.D.: ucbvax.22080 Posted: Sun Dec 6 19:28:41 1987 Date-Received: Fri, 11-Dec-87 20:46:28 EST Sender: usenet@ucbvax.BERKELEY.EDU Organization: University of California at Berkeley Lines: 41 [] Have any 1541C ROM revisions been made beyond part #251968-01? If so, what exactly are the changes? (Don't fear being too technical) ^^^^^^^ Also, any running upgrades to the electronics that I should be aware of (byond the track {zero,one} sensor)? Answers to the above would be appreciated. Here is a list of what I *do* already know: This is a summary of the changes in that -01 ROM vs. the standard 901229-05 1541 ROM: * Differing value loaded into DDRA at reset. (anti-hang) * Automatic seek to track {zero,one} at reset (-compatibility problems-) * Restarts all formats from the start, rather than trying to continue an old failed format. * Support for the track {zero,one} detector. * Modifies the fundemental frequency of the job queue. (-compatability problems-). This technique could be used to reduce time the job queue wastes waiting for the next sector header to pop up. (It might have been intended to change the step speed... but there are much better ways to do that) The save@ bug is *not* fixed, though it is very simple to add an elegant patch to the upper half. (This could even be done to the 901229-05 ROM, without affecting the lower half) I really need to know the answer to the above questions. There is also as second, unimporant question to be tossed in: What does the 1581 do about the job queue "mess"? Does it use the same technique, or something new? |\ /| . Ack! (NAK, SOH, EOT) {o O} . bryce@hoser.berkeley.EDU -or- ucbvax!hoser!bryce (") U WARNING: hoser's spool directory eats a *lot* of mail. :-(