roy@alanine.phri.nyu.edu (Roy Smith) (02/24/90)
Original-posting-by: roy@alanine.phri.nyu.edu (Roy Smith)
Original-subject: AppleScan
Reposted-by: emv@math.lsa.umich.edu (Edward Vielmetti)
Here's the scoop on my AppleScan problem. First, there's a new
version of AppleScan, 1.0.2, which you can get from your dealer. It fixes
some bugs, but it was never made clear to me if the bugs it fixed were the
ones causing my crashes. There's also a neat HyperScan stack. Second,
there's a hardware fix to old scanners (S/N < 9300249) to remove some
capacitors from the SCSI bus. They're unnecessary and sometimes cause bus
timing problems when scanning or saving large files if you have many SCSI
devices, long cables, a Quantum hard disk, and/or a fast machine (II-c[xi]).
Your dealer should do it for free; tell him it's the October 1989 repair
extension program entitled "AppleScanner Main Logic Board Upgrade".
Now, for the PostScript question. The way AppleScan (and,
apparantly, most other bitmap manipulation programs) work is to take a
greyscale image and turn it into a halftone bitmap, then send the halftone
image to the printer. Wouldn't it be better to just take the greyscale
image and send it to the printer and let the PostScript machinery do the
halftone processing? What I'm doing is proofing scanned images on my
LaserWriter, but expect to print the final copies on a high-res (2540 dpi)
machine at a service bureau. The halftones that AppleScan produces are
optimized for the LaserWriter, which seems to rather defeat the purpose.
--
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
roy@alanine.phri.nyu.edu -OR- {att,philabs,cmcl2,rutgers,hombre}!phri!roy
"My karma ran over my dogma"