mrr@rayssd.UUCP (10/11/84)
Before I begin...I recently submitted a review of the MAE assembler/devel- opment system, but I think I screwed up on distribution. If you didn't see it and are interested, let me know. Last night I realigned my secondary 1541 disk drive (sigh of relief) with the help of a software package I recently purchased from C.S.M. software of Indiana. Anyone who has owned a 1541 for more than a year (sometimes less) has probably encountered alignment problems by now, even if it is not recognized as such. The problem is especially noticable when loading programs - much clanging (head reset) and flashing of the busy light. Well, my older drive got so bad that it couldn't read disks created by the newer one (and vice versa) so I decided to do it myself. The alignment kit comes with two diskettes - a program diskette and a calibration disk. Operating instructions come in a very thin (but complete) 8 x 11 stapled booklet. My first attempt to load the software resulted in a dismal failure. after about a minute, my screen went blank and the disk continued to spin. After trying several resets, I called the company (Friday afternoon) and talked to someone technically competent who stated that the software protection scheme was preventing the load, probably because my drive was out of alignment - quite a catch-22! He asked if I had access to another 1541. I explained that I did not and that the problem was on my good 1541 which had no problems with other commercial software. That established, he agreed to mail a new set of diskettes. They arrived a week later with a return authorization for the original pair. I guess that establishes a certain amount of respectability though the additional wait was aggravating. The alignment procedure starts out with the dismantling of your drive, removing the chassis from the plastic housing, removing the metal shield and (moan!) removing the printed circuit board from the chassis. The alignment must be done with power applied to the drive in its nude condition with the pc board floating (I protected its bottom with a taped-on double sheet of paper). The first operation consists of a speed adjustment which is quite easy. You adjust a potentiometer while a speed percentage is displayed on the monitor - 100.00 % is the goal, though allowable tolerances are given. You next execute the 'Bump and Alignment' procedure which I found to be quite painful. According to the instructions, the busy light (red indicator) will stay on continuously when you have a good alignment. I never did reach that condition, so I settled for the least amount of flicker I could achieve. Also, the stepper motor cam, after a 'bump', should be pretty close to .010 inch from the cam stop. The 'Check Alignment' test actually steps through a series of tracks and sectors, using the calibration diskette, and timing the operation. After each cycle, a "T.N." number is reported which should be close to 100. Again, tolerances are given. My final result was 100.05 which I assume is pretty good. By repeating these two procedures, it appears that you can achieve a good alignment. I created a new calibration disk (on both drives) and tested them on my newly aligned drive with very consistent good results. I also made a backup copy of a large assembler application on the secondary disk, then ran the assembly on the primary using the backup with no sign of a stutter - impossible before I started. Also included in the instructions is a method for pinning the cam to its shaft (for the very brave) since it is the cam that apparently slips, causing misalignment. I may try this a few alignments down the road, but not now. This package does not have a polished, "professional" appearance. No fancy labels and documentation could be proof-read and enhanced, but I am well pleased with the results. If you have common sense, fair mechanical ability and some patience, this package will save you a trip to the repair shop and at 39.95, will probably pay for itself the first time you use it. I am very interested in others opinions and experiences with commercially available software and hardware for the Commodore 64. It's hard to get past the hype (and sometimes understatement) in advertising to determine the usefulness of a product. If you've purchased a product that you consider noteworthy (good or bad), please share it with all of us. Mark Rinfret SofTech, Inc.
doug@terak.UUCP (Doug Pardee) (10/24/84)
[] > > Last night I realigned my secondary 1541 disk drive (sigh of relief) with > the help of a software package I recently purchased from C.S.M. software > of Indiana. Anyone who has owned a 1541 for more than a year (sometimes less) > has probably encountered alignment problems by now, even if it is not > recognized as such. The problem is especially noticable when loading > programs - much clanging (head reset) and flashing of the busy light. > > ... If you have common sense, fair mechanical ability > and some patience, this package will save you a trip to the repair shop and > at 39.95, will probably pay for itself the first time you use it. > How does the price of the package compare with the 39.95 alignment? By the way, if you can bear to part with your drive for a while and feel you can trust Commodore, Commodore will *REPLACE* your 1541 with a *BRAND NEW* unit for $85.00 by mail. For those who might not know... there are two indications that you have an alignment problem. The most obvious is the BRR-A-A-A-A-P of the head mechanism being slammed against the stop, although this is normal 1) on the first use after power has been turned on, 2) during a "New" operation, 3) when loading many "copy protected" commercial programs. An earlier and more reliable warning is the sound of the head being "overstepped" and brought back in the hope that the track can be read by coming at it from the other direction. This gives a "clickity-click..click..click" sound, accompanied by the red light flashing momentarily. If this is happening with any regularity, you probably have alignment problems developing. By the way, my 1541 had alignment troubles, and I tried all of the "simple" fixes (clean the band and pullies, clean the head, adjust the band tension, adjust the track-0 stop, time the drive motor) to no avail. What fixed it was the genuine "adjust the stepper motor while watching the oscilloscope" alignment. Makes me a bit suspicious of claims that simple fixes will do the job, but this WAS just ONE instance. Doug Pardee -- Terak Corp. -- ..!noao!terak!doug