Amiga Collections: MegaDisc/MegaDisc 29 (1992-07)(MegaDisc Digital Publishing)(AU)(Disk 1 of 2)[WB].zip/MegaDisc 29 (1992-07)(MegaDisc Digital Publishing)(AU)(Disk 1 of 2)[WB].adf/Articles_I/Hints_&_Tips

Text File | 1992-08-04 | 12KB | 277 lines

                                 HINTS AND TIPS




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JUST WHAT IS USENET?

   Usenet is the largest electronic BBS in the world. Beginning as an
  informal network for Unix-based computers, it has grown hugely and contains
  quantities of information, including for the Amiga. It all began in 1979
  when two students want to hook together their computers to exchange info.

   Usenet, rather than being a centralised network like CompuServe, is a
  "distributed network" - each site connects to the next site, or sites, to
  receive and forward information, so that each site has well-defined
  responsibilities and serves as a "backbone", "branch" or "leaf" in the
  network. Usenet also gives you access to Internet (a worldwide network of
  regional networks) and Email (worldwide electronic mail).

   To get on to Usenet you need to know someone who's already connected, such
  as at a University or in a large corporation. There are "feeds" springing
  up round the place increasingly. For example I used to pay a small fee to
  get on via a computer in the North Shore which was a node.

   Perhaps anyone with information on how Amiga users can get on can get in
  touch and let us know for the next issue.


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WHAT IS S.C.S.I. ? (SKUZZY)

   The Amiga, like most normal computers, has a number of interfaces to the
  outside world - RS-232 (serial interface), IEE-488, and Centronics
  Parallel.  In 1981 SASI was devised, meaning Shugart Associates System
  Interface. But all of these had drawbacks, viz. a lack of speed, a lack
  of intelligence, and the limitation of only being able to talk to one
  device (sounds like a retarded turtle with blinkers on).

   NCR Corporation got into bed with Shugart to turn SASI into SCSI, the
  Small Computer System Interface, to address these problems,

   By allowing device-specific tasks, like error handling and buffering, to
  remain separate, a device-independent interface was presented to the host.
  And by being bus-based, communication could flow in all directions, so that
  peripheral could talk to peripheral without having to involve the host
  computer.

   SCSI was sufficiently successful to gain ANSI (American National Standards
  Institution) recognition in June 1986. It infiltrated other devices -
  optical storage, scanners, and printers. But higher speeds were required,
  to keep up with the newer processors operating at 16 and 32 bits.

   The original SCSI has an 8-bit data path, so it was natural to go to 16.
  However, the newer SCSI-2 allowed for 32-bit as well and douled the
  synchronous scommunication speed, but kept the number of devices on the bu
  (including the host) to eight. Backwards compatibility has been maintained
  to allow existing SCSI interfaces to operate correctly with the new one,
  although the user will miss out on the speed increases.

   SCSI-3 is coming and will feature the ability to handle more than 8
  devices, and an improved logical interface to go with it. It may also
  handle things like serial protocol for fibre-optic links, and a single
  16-bit wide cable.



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   MAC - AMIGA FILE CONVERSION


   If you wish to copy Mac files across to Amiga, you have two choices

i.  The conventional one of linking Mac and Amiga with a serial cable
    and then using communications software such as VT100 (or similar)

ii. If the Mac is equipped with system 7 and the 1.44Mb super drives:
    (a) Copy the files onto IBM 720K disks using APPLE FILE EXCHANGE
    (b) Read the IBM disk using MESSYDOS or DOS-2-DOS

   [Thanks to Neil Broad for this info.]



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   IMAGINE SHADOWS HINT

   [Found on the nets by David Jacobs]

   >
>Well.. Now I can do chrome and other reflections, but objects STILL won't
>cast shadows upon each other.  And I *am* in Trace mode.
>Plus, the glass doesn't look so hot.. any recommended settings?
>

        Yes, besides being in TRACE mode, for shadows you need to go
into the ACTION EDITOR and select INFO on all of your lightsources.
There is a button on the menu which says something like "CAST SHADOWS"
select it so it is on, and then those lights WILL cast shadows when you
render in TRACE.  Also, chrome or reflective objects will reflect okay
in scanline, but they will only reflect grounds,  and sky color in this
mode.

        As for glass, try a Refraction of about 1.77.




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STORAGE V. MEMORY

   This has been said before, but the distinction is worth making again and
  again, since there are always new or confused users out there who can
  easily get confused by the terminology.  Storage refers to any media that
  can hold information more or less permanently, such as floppies, hard
  disks, CD-ROMs, tape streamers, etc.  Memory (or RAM in its various forms -
  see below, or silicon memory since that's what it's made of) is something
  different - it is volatile, meaning that when you switch your computer off,
  all the contents of memory are gone.



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TYPES OF RAM CHIPS

   There are 3 main types of interest to the Amiga owner: DIPs, ZIPs, and
  SIMMs.

   A DIP = Dual In-Line Pin and is the standard chip, the name coming from
  the arrangement of its pins.

   A ZIP is different in that its shape is such that the pins are all on one
  of the edges of the chip rather than the face as in the DIP; this is so
  that they take up less space on the surface of a board, so that more can be
  fitted on. The A3000 takes these sorts of chip on the motherboard. The Z
  corresponds to the zig-zag aspect of the pins, which is obvious once you've
  seen such a chip.

   SIMM = Single In-Line Memory Module, and it is a small cirucuit board that
  has up to 9 DIP chips fitted to it; this board is then fitted in to a
  corresponding slot on the motherboard.

   All the above are known as DRAMs, ie Dynamic Random Access Memory, as
  opposed to Static Ram, which are larger and have less memory density than
  DRAMs. With a DRAM, the memory controller has to keep refreshing them, ie
  poking the same data into the chips many times per second to keep them
  "topped up", while Static ram keeps info once it has been poked in until it
  is changed or turned off.

Sizes of chips

   DRAMs come in all sorts of sizes, such as 256Kx4, 1Mbx1, and 1Mbx4, for
  example. SIMMs are quoted as multiples of DRAM chips, so you can get
  1Mbx9, and 4Mbx9.





Example of the RAM setup in the A3000:

   The A3000 has one set of 80ns, 256x4 chips soldered onto the motherboard.
  This constitutes the first meg of CHIP RAM.  Right next to these, there is
  another set of sockets for accepting another set of 8 DIPs -- giving you a
  total of two megs of CHIP RAM.  On the other side of the motherboard, under
  the drive/power chassis, is the FAST RAM expansion area.  One set of DIP
  sockets sits ready for a megabyte's worth of 256x4 chips.  Above this is a
  set of ZIP sockets which can accept either 256x4 ZIPs or 1x4 ZIPs.  If you
  use 256x4 ZIPs then RAM is increaded by increments of one megabyte for a
  grand total of four megs of ZIPs.  If you use 1x4 ZIPs then RAM is
  increased in four meg increments for a grand total of 16 megs of ZIPs.  The
  tricky part is that of the two sets of DIP sockets (one fast, one chip)
  only one set may be used.  You either have one meg of CHIP RAM and one meg
  of FAST RAM (DIP) or you have two megs of CHIP and no FAST (DIP).  This
  allows for a grand total of 18 megabytes on the Amiga motherboard, either
  in 2 CHIP/16 FAST, 2 CHIP/4 FAST, 1 CHIP/17 FAST, or 1 CHIP/5 FAST
  depending on which set of DIP sockets is used and whether or not the ZIPs
  are 256 or 1 meg chips.

   Now repeat it from memory...



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MORE ON POSTSCRIPT AND OUTLINE FONTS


   ProPage 3 now handles Postscript fonts well, as follows:

   The utility called Fontmanager will convert Adobe Type 1 fonts to
  Compugraphic format for use in ProPage - this allows those without
  Postscript laser printers to access the many thousands of Adobe fonts in
  the Public domain. For example, Megadisc has a 12-pack of Adobe Type 1
  fonts with many dozens of them, as well as a 3-pack - see the PUBLIC_DOMAIN
  drawer for more info, particularly our new FONTS_DISKS_LIST.

The FontManager program requires two files:

   * the printer font binary file which contains the actual character
  outlines and which, when supplied on MS-DOS format disks, are generally
  named <fontname>.PFB. On our Font 12-Pack, they are named <fontname>.abf.

   * the Adobe font metric file (".AFM" file) which contains info concerning
  the placement of characters, ie width and kerning data.  FontManager will
  convert fonts from any source - IBM, Mac or Amiga.

   Note that if you also want the font to be usable in Postscript output, you
  need to answer Yes to the requestor which asks if you want to place the
  downloadable font file in the CGFONTS:PS directory as well. If you don't
  do this, you will have only the necessary files for screen display and for
  printing to dotmatrix printers.

   The whole process works very smoothly with what I tried - but I have heard
  that there have been some difficulties with certain formats of Type 1
  fonts.

 Pro Draw Fonts

   Once you've converted the fonts as above, you can then change them again
  into a form that Pro Draw can use - this lets you do all sorts of things
  with them, twist, distort, curve, etc.



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VDU Radiation Risk

   [Ed: The following letter was taken, with permission, from the "Augment"
  UG magazine, and was written by Rowena Evans.]

   The June '91 article was interesting. I was told by a doctor who treats
  with homeopathy that battery watches on sick people could present a
  problem. I checked this out with Paul Alexander of the Tara Centre in West
  Perth, who uses a computer for diagnosis and identification of homeopathic
  remedies indicated. He got out a gadget which measured the electromagnetic
  field, and demonstrated on my son's digital watch and on his own analog
  watch. The digital watch gave off a very small pulse, the analog a very
  definite one every time the finger moved. I now wear a wind up watch! The
  computer screen gave off hardly anything even when measured very close to,
  the licht switch and light fittings gave off alarming signals at a distance
  of several feet. I decided the clever thing was not to have plugs,
  switches, lamps etc. in close proximity to one's body. I also have a copy
  of exercises for keyboard operators to use before and after sessions, from
  the RPH, if the club would like a copy. Plenty of shrugging and rotation
  of shoulders and head should get the blood moving.  (Checked with the
  Health Dept., and was assured that no harmful radiation eminates from
  VDU's.ED.)


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