PURPOSE This document is a description of the hook-ups and modifications that I found necessary in adding a 3.5 inch double sided drive to my Atari 520. It is intended solely as a guide to anyone who is interested in saving a few dollars by using an "industry standard" drive in place of the Atari SF314. WARNING This installation seems to function properly for my system, but I cannot guarantee anything. Also, the only way that a saving will result is if a suitable power supply is already available, or can be obtained at a very low price. REQUIREMENTS 1 3.5" Double Sided Drive w/ Installation kit @ $130 (The Unit I used was a Toshiba(tm) ND-352 which came with a multi-purpose mounting kit. BE SURE that the unit is XT compatible!!(720K)) 1 34 pin Card Edge Connector @ $ 3 1 Standard Atari(tm) 3.5 in Disk Drive Cable @ $ 8 PRODECURE There are two ways to proceed with this project depending on whether you want the new drive to be A or B. The Drive B method is the simpler, so I will start with it. _____ 1. Cut the Standard Drive Cable in half _____ 2. Strip back about 2" of the outer insulation from the cable. Do Not cut off the shield wire (a layer of wire woven around the multiple conductors in the cable). Carefully unweave the shield, and twist it to form a wire of its own. _____ 3. Since the 34 pin connector that I used was designed for ribbon cable, some ingenuity is required here. The Connections Follow: (NOTE: the colors mentioned are for an Atari Cable. You should check if you are using an After Market Cable.) 34 pin conn. Atari conn. Signal Color 2 * media chng 4 N/A in use 6 N/A d4 sel 8 4 index yellow 10 5 d0 sel green 12 6 d1 sel violet 14 N/A d2 sel 16 8 motor on brown 18 9 direction orange 20 10 step grey 22 11 wrt data pink 24 12 wrt gate lt. blue 26 13 track 0 lt. brown 28 14 wrt prot lt. green 30 1 read dacrosoft (Presentation Manager), Carnegie-Mellon University, and oddly, even Sun Microsystems' Open Look interface. Afterwards, it will consider whether it should base its standard on an upcoming release of AIX, IBM's version of Unix, or some other Unix dialect, like Berkeley Unix. The OSF estimates that it will have its alternate Unix standard complete by early 1990, while AT&T is saying that Unix Version 5.4 will be shipping by Fall 1989. This gives AT&T (if they deliver on time) at least eight months in which to retake the Unix market. AT&T has already begun to do this by rallying support for Open Look, as toolkits for this graphical interface will be available in the First Quarter of 1989. Then, the question becomes if AT&T and Sun alone should be able to dominate the course of Unix, as IBM/Microsoft have the course of MS-DOS, without the help of other Unix licensees, or if a group of Unix vendors will be able to muster great support for their Unix without AT&T. With the advent of OS/2, the computer industry finally began to take a look at multitasking operating systems, and noticed Unix, with its powerful capabilities. As such, Unix has become very important, having the potential of eventually guiding the microcomputer industry into the 21st Century. Now the issue is if Unix not only can overcome the MS-DOS, Macintosh, and OS/2 alternatives, but can withstand the dissention within its internal ranks to establish a standard worthy of such a feat.... But ponder, if you will, on these two questions: 1) What exactly are the capabilities of the Atari ST and Amiga's bus architectures? 2) What steps do users take to replace or supplement their systems when they become obsolete, orphaned, or don't have enough software? ---=====***=====---