NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/sys/amiga/hardware-part1/3663

Text File | 1996-08-05 | 13.8 KB | 313 lines

Path: uwm.edu!msunews!raine
From: [e-mail] (Robert Owen Raine)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: a3000 boot prob
Date: Mon, 05 Feb 96 16:30:47 GMT
Organization: Michigan State University
Message-ID: <4f5b1b$[e-mail]>
References: <4f59jp$[e-mail]>
NNTP-Posting-Host: raine.pa.msu.edu
X-Newsreader: News Xpress Version 1.0 Beta #3

In article <4f59jp$[e-mail]>,
   [e-mail] (Kilroy) wrote:
>get a grey screen...what does that mean???
-----------------------------------------
Power-up operation summary (tests, LED blinks, screen colors)
(Hans Hansen)
Newsgroups: comp.sys.amiga
Subject: Screen colors and other boot things
Date: 16 Jul 87 01:42:24 GMT

Dark gray            Ok Hardware
Light gray           Ok Software
Red                  Bad ROM Checksum
Green                Bad RAM
Blue                 Bad Custom Chips
Yellow               Exception

(INITIALIZATION FROM OS ROMS)
Clear Chips
Disable DMA and Interrupts
Clear the Screen
Check the Hardware
Pass or fail the Hardware to the Screen  (BLUE|BAD) (DarkGray|OK)
Checksum the ROMs
Pass or fail the ROMs to the Screen    (RED|BAD) (LightGray|OK)
System setup (..is finished)

Check the RAM at $C00000
Move SYS_BASE to $C00000 if it exists
RAM Test ; hummm.... not very good though needs to indicate hex location
Pass or fail the RAM to the Screen (LED Blinks 9short 1long | GREEN | BAD)
Check the Software
Pass or fail the Software to the Screen  (Yellow|BAD) (LightGray|OK)
Set up the RAM
Link the Libraries
Find External RAM and link it to the list
Set up Interrupts and DMA (for boot drive especially)
Start default Task
Check for 68010, 68020, and 68881
Check for an Exception (System Alert?)
System Reset (..Let the good times roll!)
----------------------------------------------------------------
Tips for Smooth Operation of the Amigas
by Bryce Nesbitt & Bruce Takahashi

(previously written a couple of years ago)

1) For the Amiga A1000, connect the pin #10's (ground) of the four PAL's
together on the daughter board with heavy wire.  Apparently the signal
ground path is strange and creates unreliable logic signals to U6J, U6K,
U6L, and U6N.  If you want a better connection, wire the mother board and
daughter board grounds together.

2) Check the expansion hold-down screws for proper length (not too long)
Sometimes the screw will bend and short the second of the two layers of
sheet metal to the circuit board. It may be best to try and first set the
screws without the video expansion ram to "pre-tap" the sheet metal. It
will be easier then to snug the hold-down screws for the expansion card.

3) Push all chips down fully into sockets.  Some chips may not be seated
properly or even have bent pins.  Straighten bent chip pins with a pair of
smooth pliers.

4) Preferences has a screen centering gadget that if moved too far to the
left, will cause some of the sprites to be distorted.

5) For programmers:
        a) Use this instead of AllocMem():

#include "exec/memory.h"

/* Safe AllocMem.  Will not let your run the system down to zero bytes.
 * For all to use, by Bryce Nesbitt
 *
 * You may wish to increase PANIC_FACTOR.
 */
#define PANIC_FACTOR_CHIP 4096L

APTR SafeAllocMem(size,flags)
long size;
long flags;
{
   register APTR p;

   if ( p=(APTR)AllocMem(size, flags) ) {
      if ( AvailMem(MEMF_CHIP) < PANIC_FACTOR_CHIP ) {
         FreeMem(p,size);
         return(0);
      } /* System is low... no go! */
   }
   return(p);
}

If you need to tell the user that the system is out of memory, but there
is not enough memory to post a requester or Alert, simply set the title of
your Window or Screen to "** NO MEMORY **" (possibly with a red pen
color). This operation does not require any allocations. b) There is a bug
in Text() that will clip text too soon if the write is started from beyond
the left edge of the RastPort. c) WindowToFront() (and probably the other
Intuition "deferred" actions) will lock up if the user is holding down an
icon from the Workbench tool.

6) If you use internal memory expansion, you should ground clip the
motherboard to the internal expansion board, preferably at the point on
the expansion were the ram array is.

7) Use only high quality disks. Poor disks may format and copy correctly
but time may find lost data or files.

8) Make sure that your machine's fan is unobstructed and operating

9) Use a single AC power outlet with enough grounded power sockets for all
your equipment.  This keeps the AC polarization correct between all your
equipment power supplies. If you examine a three prong outlet, you will
notice that it looks like a pair of eyes with a mouth.  The mouth is
supposed to be electrical "ground"; the smaller slot is the "hot"; the
larger slot is "neutral".  A power plug without a ground prong may have
one of its contact blades larger to fit only in the "neutral" slot. Don't
ever defeat it's purpose. To do so will endanger you and your equipment.

10) This should have been ICHI BAN: Never connect or disconnect cables
while equipment are powered, or blindly probe for a mating.  This includes
your printer, external drives, modems, and other peripherals. Modems, for
instance, have +/- 12 volts on its pins.  Damage can result when these
pins accidently touch the wrong pins on the computer.  Always check to see
that you have the appropriate cable and cable adaptions before you attempt
usage.

11) Don't guess where the cables connect.  Look where you plug your
equipment.  The A2000 has a round DIN connector for the keyboard. Always
make sure the connector marker is on top before plugging.  Don't do as
many people do.  Don't insert and then twist until it fits.  This will
slowly damage your connectors.  IBM PC keyboards are not compatible.

12) Be very careful that the metal band around your mouse connector
doesn't short the pins of the mouse port when inserting.

13) If you encounter a power failure, turn-off all your equipment. When
power is turned on by your Electric Company, your equipment may experience
damaging power spikes or fluctuations.

14) Remove disks when shutting-down a system. Park your harddrive if it
is not the auto-parking type.

15) Video monitors develop high levels of static electricity.  It is best
to plug the monitor and computer into the power outlets before connecting
the monitor cable. Always use a 3-prong power outlet. If your monitor plug
wasn't designed with a ground prong, use a power outlet that is correctly
polarized.

16) Always snug and not tighten the thumbscrews or clips to your
connectors.

17) Never place magnets near your monitor.  This includes speakers,
printers, and telephones which develop magnetic energy.

18) Be sure to include in your startup-sequence file a stack command.
However, programmers should check the stack size if they need more than
4000 bytes-Operating System overhead. I *don't* increase my stack, or if I
do it's to 8000. (Now you know what me, myself, and I do.)

19) Before working on the interior of your computer, always touch either
the disk drive's or power supply's metal casing to discharge any damaging
static electricity.

20) The Amiga monitors have a metal shield installed under the casing. If
you are using a non-Amiga monitor, make sure that your monitor has some
shielding or make one using a metal kitchen tray (?).

21) Don't mix and blend versions of operating systems. You are asking for
problems and will get them most of the time. If you are still using older
software, you are asking for problems anyway.

22) When paying for shareware and you want a response from them, cut the
bill in half and staple a note as to where the other half went. Nah, don't
do it; it's illegal.  Darn my buckies!  I just became a felon when I
thought
of an excellent programmer.

23) When plugging in cards for the A2000 Amiga, there is the end of the
card which screws to the back of the Amiga.  The metal bracket, which is
attached to the card for this purpose, has a tendency to catch at the
bottom of the bracket to the casing of the Amiga.  To seat properly, the
bracket must be pushed against the back of the Amiga and then it will move
further down.  Make sense?  The main point is: Don't force the bracket to
seat and especially don't use the screw to force it to seat! Always screw
the cards down to prevent shorts

24) Genlock for the Amiga may need some modifications to sync properly.
The modification needs to be done on the early models and requires that
R55 resistor be removed and R108 to be changed to 1.5K ohms. R55 is a
4.7K ohm resistor located near the Q3 transistor, and R108 is a 1K ohm
resistor located near pin#10 of the MC1377 chip.

25) The composite video of the Amiga A1000 needs color correction. Your
red, greens, and blues may not look correct.  The modification is simple;
just remove resistor R140; located on the rear-left of the motherboard. On
some A1000's, R140 will have to be replaced with a 470K ohm resistor
instead.

26) CORRECTED!

27) Keep your equipment out of sunlight; even when reflected by mirror or
walls while you are away from home. Overheating problems are increased if
the power supply vents are blocked or if it is resting on a rug. Keep the
power supply in a well ventilated area.

28) You cannot keep your cat or dog's fur out of your internal disk drive.
The fan sucks through there. Internal drives now have spring loaded doors
on the front which help in reducing contamination.

29) A clean mouse is a healthy mouse.  Clean your ball and rollers with Q-
Tips, rags, toothpicks, picks, and jack-hammers.

30) Sticky keyboard keys?  Remove that key button with a chip puller and
clean both button and switch with Q-Tips and alcohol.  If your lucky, the
shank of the key switch isn't split.  If it is, The split will widen in
the switch and wedge. Replace the switch or oil the shank with 3in1 oil
only. You may get lucky and find a repair station with some damaged
keyboards with good switches.

31) Does your monitor seem to sink into your A1000 computer case? Put a
plywood or 1/4 inch plexi-glass platform underneath. Does your A2000
keyboard seem to sink in the middle? Re-enforce the middle of the
keyboard's circuit board with a rubber spacer. Does this list seem a bit
long? Make some hot apple cider and come back here.

32) If one or more of your mouse buttons goes flaky, it can be replaced.
If the switch is "Flag", with a square body about 12mm in size with four
leads you may be in luck.  If the switch is the type where the actuator is
completely flush to the switch body, the replacement part can be had from
Panasonic; Digi-Key (1-800-DIGI-KEY) sells it as part #P9950, 36 cents
each. If the switch button is slightly raised from the main body (by about
1mm) you will either need to adapt the above part or try and find a better
match.  Mouser electronics (817-483-4422 or 619-49-2222) part # 10KB001,
49 cents each, *might* do the job. Some mice switches are dual switches
with only half being used! Use the other half by rotating the switch 180
degrees.

33) GET MEMWATCH from John Toebes!!

34) CORRECTED!

35) Dead Issue.

36) Ribbon cables should never be bent at angles to the degree of being
sharply folded.  All folds of ribbon cable should gently loop.  A sharp
crease can damage, short or break the wires inside the ribbon cable.  In
the cable from the disk drive mechanism, this can mean Guru's or the
device not being recognized.  MANY RIBBON CABLES FOR THE BRIDGECARD HAVE
BEEN DAMAGED BECAUSE OF THE CREASES IN THE PACKAGING OF THE PRODUCT.
THIS
HAS DAMAGED DRIVES AND BRIDGECARDS. IF A RIBBON CABLE IS SHARPLY FOLDED,
USE AT YOUR OWN RISK.

37) Copy and run questionable or unknown programs in RAM disk with your
disks removed or write protected.  This will prevent you from crashing the
disk drives and damaging the disks.

38) Corrected!

39) For A2000 users with BridgeCards, keep the ribbon cable going to the
5 1/4 floppy away from the motherboard. Lay the ribbon cable on top of the
cards instead of underneath.  The ribbon cable picks up interference which
can cause your machine to intermittently GURU or cause devices not to be
recognized. (*** note *** Some A2286 bridgeboards will display parity
errors. Return these for exchange.)

40) All computer equipment need a minimum amount of time before powering
back on-line.  For the Amiga A1000 and A500, you must wait a minimum of 20
seconds before power-up and as long as 30 seconds or more for the A2000
Amiga. Computers need time to completely power-down and discharge all
voltages which may be sustaining corrupted data in RAM and other chips.

41) If your computer monitor remains powered and unattended for extended
periods of time, use a display blanking program.  This type of program
will "black-out" your display until there is some kind of user action from
the mouse or keyboard.  Your display will temporarily "black-out" after a
set number of minutes of inactivity.  Public domain programs like "PopCLI"
from the Software Distillery and "ScreenSaver" from Perry Kivolowitz are
good examples.  Leaving the colors stationary for days on end will
burn-out the phosphors of the monitor leaving you with a ghost image
of the display forever. I set my screen to black-out after 10 minutes of
inactivity.

42) It's a good idea to assign your T: directory to RAM:T before executing
any command script. The reason is increased speed and less drive activity.


Hope these tips help. Try 3 that is often the problem.



                                                          \|/                                                                                            @ @
------------------------------------------------------oOO-(_)-OOo--------------
Only Amiga Makes it Happen                      Bob Raine
The computer for the creative mind              Michigan State University
Make Up Your Own Mind                           Physics Astronomy Dept.
Amiga / The Alternative                         [e-mail]:
            "Anything is Possible"
-------------------------------------------------------------------------------