kamath@reed.UUCP (Sean Kamath) (04/24/87)
In article <8704220543.aa00402@SPARK.BRL.ARPA> LB0POPER@MIAMIU.BITNET writes: >I have an Apple //C that I've had for 2.5 years and I recently have come >up with a couple of simple mechanical problems, one of which I hope can >be solved by someone out here without much difficulty. My external 5.25 >drive has recently gone out of wack and occassionally messes up a prodos >catalog (which kills the disk). I feel that, since I haven't had to do >any work on my Apple, the problem is probably simple. Does anyone know >how to aligh disk drives easily. > >Thanks a lot > >Lonny at LB0POPER@BITNET Disk head alignment is no mean feat. TO be done correctly to need a scope, a special disk made my Dysan called the Digital Diagnostics Diskette (which CANNOT be copied except with special hardware and costs somewher in the neighborhood of $75 for dealers) and an alignment guide. However, it might not be your alignment. If you are having problems only with Prodos, there is a major bug in Prodos, that eats directories. Originally thought to be power supply problems, it turns out that proloss leaves the disk in write mode at certain times. this means that while the disk is spinning up to speed, it might actually be trashing whatever is flying underneath. This is usually the directory. I'm not entirely sure which version of prodos this patch is for, but is shouldn't be hard to find in any version. BLOAD PRODOS,TSYS,A$2000 UNLOCK PORDOS CALL -151 [Look for this sequence... 9D 80 C0 STA $C080,X 9D 80 C0 STA $C080,X 9D 84 C0 STA $C084,X 9D 86 C0 STA $C086,X replace the 9D's with BD's.] BSAVE PRODOS,TSYS,A$2000,L14848 in one version of prodos it's at $56D3. ________________________________________________________________________________ Sean Kamath UUCP: {masscomp, decvax, allegra, psu-cs, ucbcad, ucbvax, purdue, hplabs, hp-pcd, sequent, uw-beaver, ihnp4, cbosgd, gatech, nsc-pdc}!tektronix!reed!kamath CSNET: reed!kamath@Tektronix.CSNET BITNET: reed!kamath@Berkeley.BITNET ARPA: tektronix!reed!kamath@Berkeley reed!kamath@hplabs DECNET: RHEA::DECWRL::"decvax!tektronix!reed!kamath" US Snail: Box 395 Reed College, Portland, OR 97202 (503) 239-7458 These are not the fastest or best paths, just the easiest to use. I hope they work. (Most notably the US Snail Service :-)