[comp.sys.apple] mountains, DigiPack, clone 3.5 drives

c60c-3aw@tarantula.berkeley.edu (Andy McFadden) (10/16/88)

Yet more miscellaneous stuff, starting off with comments about the fractal
mountain generator I posted to comp.binaries.apple2 the other night:

1. I let it run all night with a smoothness of 2, a complexity of 8, and a seed
   of 50.  It looked pretty nice, but it died sometime after a few hours (got
   probably 2/3 done).  I have 768K of RAM, but 128K was used by the RAM disk
   and ProDOS 16 probably grabbed a bunch more... it could have been a problem
   with a stack overflow or just poor garbage collection.

2. I managed to resolve the problem with not being able to save the screen
   easily:

   a. Hit open apple - control - reset, and boot into ProDOS 8.  The memory for
   the SHR screen is from E0/2000 - E0/9FFF, and won't be disturbed by most
   programs.

   b. Get into the monitor, type "C029:C1" to see your picture.  If everything
   is okay so far, hit ctrl-T to return to text mode.  Create the file with
   "CREATE <filename>, T$C1" (uncompressed SHR pic)

   c. Move the picture into bank 0, one half of it at a time.  Type
   "00/2000<E0/2000.6000M" to move the lower half down, and save it with
   "BSAVE <filename>, A$2000, L$4000".  Note that you might have to return
   to BASIC with ctrl-C for this to work; I'm not sure about whether or not
   the bank registers will screw up ProDOS's operations.

   d. Move the rest of the picture with "00/2000<E0/6000.A000M".  Now append it
   on to the first file with "BSAVE <filename>, A$2000, L$4000, B$4000".

   Now crank up SHRConvert or a paint program to see if it worked properly.  A
   paint program would probably be more useful; it would be nice to remove the
   "press any key to continue" from the top of the screen.

3. Now, a note to dkletter (couldn't get mail through, but this is really
   of general interest anyway):

   The reasons for using DDDeluxe are:
   a. (I sure like outline formats) It compresses things smaller than standard
      DDD does,
   b. It runs faster than most other programs, and
   c. It allows you to put a brief bit of text at the beginning.

   Reasons a and b came from some benchmarks that somebody performed; oddly,
   DigiPack GS was not represented in these benchmarks.  I am also aware
   that DP Optimized format allows you to put a message there, but Optimized
   only works on ProDOS disks as far as I know.

   The real strength of DigiPack is its use of GS memory; not having to swap
   more than once is *very* important on a one-drive system.

4. Another comment about my CPS 3.5 drive (GOD I HATE THIS THING!):
   When unpacking things sometimes, the disk will develop an I/O error on one
   of the blocks.  This is NOT an unpacking error, it is a mangling of the
   disk format.  I tried unpacking a program once with DigiPack and DDDeluxe,
   and both consistently left errors on certain blocks (each program
   killed the same blocks each time, but each did DIFFERENT blocks... weird).
   I had to unpack twice and combine the working parts... a real pain on an
   800K disk.

   The only thing I can think of is the continual on-off activity of the
   drive while unpacking; I have had strange things happen while saving
   pictures with SHRConvert (physical I/O error, corrupted files).  When
   I saved them to the RAM disk and copied them with Copy II Plus, the
   images were undamaged!

   I've said it before and I'll say it again: STAY AWAY FROM CLONE DRIVES
   UNLESS YOU ALREADY HAVE A FULLY FUNCTIONING STANDARD APPLEDISK 3.5!

    <setenv RANTNRAVE off>

-- 
fadden@zen.berkeley.edu [crashed]
c60c-3aw@widow.berkeley.edu (Andy McFadden)

"This is the comment that has been previously omitted."