Content Index Prev Next

 Compatibility problems / Bridgeboard Problems

The best way to think of the Bridgeboard is as an IBM on a card stuck in your Amiga. 
The only parts of the IBM that are being emulated are the keyboard, mouse, hard drive, and display.
Even for some of these they can be replaced by the real thing.  For example its possible
to install a Microsoft mouse, or a I/O card with a real hard drive or a VGA card.  Despite all of  
that, I'm sure that you'll probably find some software or hardware that doesn't like the Bridgeboard.
Below are some problems and their fixes (if they have one):

 - DosShell turns to garbage when I select a graphics display.

This is a fault of the AMouse driver. You must either run DosShell in a text display or use a
real Microsoft compatible mouse.

 - The AMouse driver doesn't operate with program "#####".

The AMouse driver isn't that great under DOS, your only fix for this is to install a real Microsoft 
compatible mouse on the Bridgeboard.


 - My hardfiles don't work.

The most common problem is that you have an 68030/040 CPU. With these CPUs you need to either:

- Turn the CPU DataCache off or
- Install the Enforcer utility (if your CPU has an MMU)


 - My hardfile access is very slow.

 If you increase the buffers on the hard drive that has the hard file on it your access time will
improve.  You need to add A LOT of buffers to make it faster (like 800 to 1000 buffers).  Also,
hardfile speed is based on the size of the hardfile, a large hardfile is slower than a smaller one.
(Check out JanusTools for partition support).

- I can't get the AMouse or ATime to work on the Bridgeboard side unless I do a warm boot on the PC
  side.
   (This might happen after doing an install of some software or hardware drivers)

From: Stewart Hunt

Try the following:

Open your config.sys file and look for a "Stacks=9,256" line.

If it is present or missing, either change it to read, or add the line,

Stacks=0,0

Save the new Config.sys file and reboot, the problem should go away.
Some MS-DOS versions try to "help" device drivers by providing them with
a new interrupt stack. IRQ3 (used by Janus for hardware AND SOFTWARE
interrupts) is frequently a victim of Microsoft's benevolent aid, and
their stack switching code destroys registers which are parameters for
software IRQ3 calls to Janus, and thus Janus cannot be reached by
applications. Stacks=0,0  says "Don't help me Microsoft".


 - My A2286 (or other) Bridgeboard locks up intermittently.

From: Scott Drysdale

(Peter Kittel Germany) writes:
>
>If you have such mysterious faults with your bridgeboard, I assume the
>old story: contacts, contacts, contacts. Reseat all socketed chips.
>Reseat all cables. Reseat card in its slot. If it doesn't help, try
>again. One BB of mine needed 5 attempts until it worked. Keep trying.
>
>You could also consult comp.sys.amiga.emulations, there you find more
>BB experts.

also get janus 2.1 if you haven't already.  there are gazillions of small
bugs in janus 2.0 that can team up to form one big bug when the temperature,
humidity, and phase of the moon are all just right.

in your reseating activities, pay particular attention to the alignment of
the card fingers with the corresponding metal brushes in the motherboard
connectors.  some bridgeboards and/or amigas have slight misalignments,
and you may want to file a little bit off the edges of the bridgeboard
connectors...

---|__________________|--|_______________________________|----

   ^                  ^  ^                               ^
   a                  b  a                               b

file at the two 'a' areas to get the fingers more to the left.  file at the
two 'b' areas to get the fingers more to the right.  the AT bus connector's
brushes may align differently with the board's fingers than the zorro stuff.
find a happy medium that keeps both as close to centered as possible.

 - My floppy drive doesn't work.

From: Scott Drysdale

since i've been asked about shared drive woes by several people, i'll
describe your problem and another common (and much worse) problem.

your problem is most likely noise.  early dual-speed drives were very very
sensitive to environmental noise.  how to "fix" this one is too dependent
on the individual machine.  the drive could also need cleaning.  it might
be dead.  try to borrow another 357A drive and see if it works with your
2386 (test all four combinations - amiga DD & HD and PC DD & HD).

---------------------------------------------------------------------------

here's how the shared drive thing works:

                              +--------------+
AMIGA FLOPPY CONTROLLER ------|A             |
                              |  A/B SWITCH  |--------- SHARED DRIVE
   PC FLOPPY CONTROLLER -+----|B             |
                         |    +--------------+
                         |
                         +-------| GATES |------------- EXTERNAL PC DRIVE
                         |
                         +-------| GATES |------------- INTERNAL PC DRIVE

the A/B switch (flipper hardware) is really more than a simple switch.
it has to allow the amiga to detect disk insertion/removal even while the
PC owns the drive, and it also controls the dual-speed drive's "gearshift."

the switch is built out of several PALs and is controlled by a few jumpers
and the software-controlled configuration registers.

what happens is the PALs go bad.  i've heard of GAL chips "reprogramming"
themselves due to overshoot on their i/o lines, which gets rectified and
fed to the chip's power supply.  i suspect this is what's happening, given
the miles & miles of ribbon cable the signals are travelling through.

my bridgeboard at home has this problem - maybe one in 50 power ups result
in a working shared floppy drive.  in my case, the bridgeboard speaker also
stops working (which tends to implicate a particular PAL, but i don't
remember which one).

--------------

your options:

1) hook up an A1010/A1011 drive to the rear port of the 2386.  this gives
   you a 720K external PC drive.

2) do #1, but install a real IBM PC compatible high-density drive in the
   A1010/A1011 enclosure.  the A1011 is probably easier, since it uses
   a more modern mechanism.  you'll probably have to play with the select
   jumpers on the drive you use.

3) install a real IBM PC compatible high-density drive using one of your
   drive bays.  attach the drive to the "internal" cable that came with
   the bridgeboard.

4) find a service place (try ESCOM, CEI, or SMG) that can make you a new
   set of PALs.  i don't know which one(s) die, so get a whole set.  i'd
   get out a scope and watch the signals to see if they're over/undershooting
   badly, and try to fix it with diodes/pullups/series resistors.

5) if you have no need to boot the PC side from floppies, run CrossDOS on
   a dual-speed drive.  use AREAD/AWRITE to move files back & forth.

if you change anything, don't forget to tell both PC BIOS and PCPrefs about
the changes.
_______________________________________________________________________________


 An other possible solution is to reduce the size of the ribbon cables as
 described in 'Installation tips' in Bridgeboard Tips and Utilities - I have problems getting my Bridgeboard to work when I have 8MB of RAM

as best described by: Michael Pederson 

        The problem with BridgeBoard Autoconfig occurs only in Zorro II
based Amigas and is common to all BridgeBoards.  The Zorro III Amigas
configure RAM outside the Zorro II address space and so they don't run
into a conflict.  It's caused by the BridgeBoard trying to Autoconfig
itself into Zorro II FastRAM address space, of which there are only
8 Mbytes available.  If this is already occupied by 8 Mbytes of FastRAM,
a BridgeBoard will lose.
        The only solution to this problem is to limit the amount of
FastRAM to 7.5 Mbytes; as you've pointed out, most upgrades are in
increments of 2 Mbytes so in practice the limit becomes 6 Mbytes of
FastRAM.
        The only cards I know off the top of my head that aren't
restricted to 2 Mbytes are the A2090/2091 SCSI controllers.  These can
be configured to 1/2, 1 or 2 Mbytes FastRAM.
--

Please also note that the DKB2630 board can apparently add memory outside the Zorro II
Autoconfig space, thus solving the problem.

 - Always getting a message that Janus.library cannot be found.

This could be caused by a couple of different things.

- You don't have the "binddrivers" statement in your startup-sequence.
- You don't have the "Janus.library" in the Expansion drawer on your boot drive.
- You have all 8 megabytes of Autoconfig RAM used up (can only have 6 megabytes of Autoconfig
   RAM for Zorro II Amigas; see above)

 - I can't get my floppy to be shared with the Bridgeboard in an A4000T

It's not possible to share the floppy with the Bridgeboard in an A4000T setup because
of some differences in the onboard floppy controller of the system. Your only option is
to use a dedicated floppy drive for the Bridgeboard.

 - After upgrading the A2386SX's CPU, my FPU unit no longer works/gives errors or programs
   refuse to work properly.
        
It has been reported that some CPU upgrades/FPUs are incompatible with each other. The Cyrix Cx486Srx2
upgrade is known to be incompatible to most (if not all) FPU coprocessors.

  From: Stewart Hunt 

  The Cyrix Cx486Srx2 microprocessor upgrade chip has been widely used to
  upgrade the C=2386 bridgeboard to levels similar to a 33 MHz 486
  system. I have the 50 MHz chip installed over the 25 MHz Intel 386 SX
  processor. If a 387SX math coprocessor chip is installed on the
  bridgeboard, diagnostic software indicates a 486DX processor is in
  place. While the Cyrix microprocessor claims to be compatible with most
  any math coprocessor installed in the math coprocessor socket, my own
  personal experience to this point, indicates that it is *NOT*. I have
  tried the Cyrix Fastmath 387 chip, the Intel 387 chip, and the ULSI 387
  chip. Both the Cyrix and Intel chips fail the Transcendental math tests,
  included in the Cyrix or Intel advanced diagnostic software which is
  provided by the respective manufacturers. The Intel 387 chip also fails
  the Environment test which tests the 80 bit wide internal math
  co-register stack. The Transcendental test is for trigonometric,
  exponential and logarithmic functions. When the Cyrix CPU chip is
  removed from the 2386 BB the diagnostic tests are all passed
  successfully and the diagnostic software indicates that the math
  coprocessor is installed and operating correctly. Disabling the cache
  on the Cyrix CPU still results in the failure of the diagnostic tests
  on the Transcendental and Environment tests.  All of the other math
  coprocessor tests are successful. Clearly, the tests seem to point to
  an incompatibility of the Cyrix chip, and the 8387 math coprocessor on
  Bridgeboard systems. Ignoring the diagnostic errors, has been of little
  consequence running DOS and Windows software, but it will cause major
  grief running OS/2 applications.

Something to keep in mind, however:

 ›From: Scott Marlowe 

  Please note that MANY of the "transcendental tests" written by one
  manufacturer will FAIL on anyone else's math chip due to the last
  bit being wrong according to these tests.  The problem here is that
  the last bit is often not considered reliable, but they test it
  anyway.  I remember reading about how INTEL wrote a tran test for their
  387 mathco that then failed on the 486DX, because the 486DX was more
  accurate.  Don't get worried about the last bit or manufacturer's tests.

One possible cure is to remove jumper J101 on the Bridgeboard, which disables Pipeline mode. This may
get programs that usually don't work with the FPU to work properly, at the cost of a slight performance
loss.


 Other Frequently Asked Questions


Q: Is there a video driver that allows me to display the PC screen on my AGA
   machine/graphics card?

A: There is no such driver, and probably will never be as the amount of data that would have
   to be transferred from the PC to the Amiga would probably make the display update very slow.

Q: How do I install the AMouse3.drv in Windows?

A: The AMouse3.drv (comes with Janus 2.1), will operate under Windows 3.0 and 3.1, however you have to 
   install it manually.  First install Windows, then enter your Windows directory and edit the file called 
   "SYSTEM.INI".Find the line called "mouse.drv=#####" and set it to "mouse.drv=amouse3.drv". Lastly,
   put a copy of the AMouse3.drv in the "system" directory found in your "windows" directory. (Also see
   the section on Setting up an OEM mouse driver for Windows for the proper Windows
   method.)

Q: How do I run my Bridgeboard with the CGA driver under Windows 3.x?  
        
A:   "Be warned:  It looks like utter crap.  However, it works."
                                            - Scott Drysdale

   If you can't/won't get a VGA card for the Bridgeboard, here is how to install the CGA driver (this only
   applies to Windows 3.x; Windows 95 requires VGA minimum).

      There is a CGA emulation driver located in the JANUS directory called VDDCGA.386 which is needed to use
   Windows in CGA mode. However, the file alone is useless; the Windows 3.x CGA driver disk is needed and
   available at http://premium.microsoft.com/support/downloads/dp258.asp (you might need to register with
   the Microsoft site first), which points to 'CGA.EXE'.

   Expand the file to its own disk by running it from the floppy or by running 'CGA.EXE A:'

   Delete the file VDDCGA.38_ from the disk, and copy the file VDDCGA.386 from the PC JANUS disk to it.

   For kicks, you can change the "CGA" description in the OEMSETUP.INF file to something like "Bridgeboard CGA
   Emulation". This is now the CGA Driver Disk.

   [For convenience, I have included the CGA Driver Disk in the archive "BBCGA.ZIP" online]

   Install Windows using the custom install method (or run Setup under DOS to bring up the configuration program
   for Windows if already installed).
   
   Once at the 'hardware and software components' screen, go into "Display:"

   Select "Other" and point it to the CGA Driver Disk and select the CGA driver.

   Continue installing Windows (or restart it).
   
   Please note that under AmigaOS 3.1 the colors might be worse than other versions of the OS. You might also have
   select 'Restore Settings' from the Project menu of the PC Color program to get the proper display.
   
Q: Can the A2386SX Bridgeboard be upgraded to a higher processor or speeded up?

A: Yes, it can be upgraded all the way up to a 486SLC at 75 MHz. See Bridgeboard Tips and Utilities
   for Bridgeboard CPU upgrade guide.

   Some PC software utilities (such as Qfresh or CalcQF, found on the Simtel MS-DOS archive) will
   allow you to alter the RAM refresh rate, which might yield some speed improvements.

   It has also been reported that changing the crystal oscillators with faster ones will allow
   to speed up the Bridgeboard, but beware that some (older) ISA cards might not function as well
   at the higher speed.

Q: Can the A2286 AT Bridgeboard be upgraded or speeded up?
        
A: Yes. A A2286 Bridgeboard user has been able to upgrade it with a Cyrix Make-it-a-486
   (486SLC33) upgrade. Since the daughterboard is above the processor, the connector for it must
   be extended to accommodate the upgrade. This will unfortunately take up the space of two Zorro 
   slot when installed.
   
   It has been reported that Windows 3.1 runs on the upgraded Bridgeboard, but Windows 95 fails to
   install properly.
        
        
   Also, from Scott Drysdale:
        
   "it might be possible to find a 286 to 386SX upgrade widget, but you'd
   have to look real hard.  and you might have trouble fitting it on the
   2286, since the CPU's under the daughterboard.  you'll also have to
   expand beyond 1M of RAM with an AT bus memory board, which will give
   you a blazing 8MHz memory bus.

   you should try to find an A2386SX.  if you really want to use the
   2286, fix it!

   the 2286 has a couple of hardware bugs that affect the keyboard and
   A20 gate control.

   here's one that's easy to fix, and should be done to all 2286s.  the
   problem is that the 8042 responds to too many I/O addresses.  the
   fix makes it respond only to the proper I/O addresses.

   - put the bb in front of you with the component side up and the edge
      fingers towards you.

   - remove U72 (8042 on the daughterboard) from its socket and carefully
     bend pin 6 so it sticks straight out.  put the chip back.  pin 6
     should be hanging out in the breeze.

   - solder a wire from U72 pin 6 to J17A pin 30.  J17A is the connector
     nearest you that attaches the daughterboard to the main board.  the
     pin you need is 2nd from the left on the upper row.

   this fix will also drastically speed up 2286<->amiga communications
   (fake pc hard drives that live on amiga drives, aread/write, etc).

   the other bug is that the simulated keyboard in the ABT/DBT chips
   doesn't handshake properly.  it should do this:

   - wait for the 8042 to indicate it's ready for data.
   - shift data out to the 8042.

   instead, it does this:

   - shift data out to the 8042.
   - wait for the 8042 to indicate it's ready for data.

   the effect is *lots* of lost keystrokes when running in standard (286)
   or enhanced (386) mode, because the 8042 is frequently doing something
   other than listening to the keyboard.

   the A2386SX has a PAL, EPLD, and matching 8042 code changes to fix this
   bug.  there's no fix for the 2286"


Q: Why are there files missing in my setup?

A: Appendix E of the Bridgeboard manual lists all the files that are supposed to be in the
   appropriate directories, but in page 4-24 of the Bridgeboard manual, the missing command
   'XCOPY A:\DOS C:\JANUS' has to be executed in order to copy all the required files.

Q: My Bridgeboard is beeping, what's wrong with it?

A: When the Bridgeboard encounters a problem, it will beep. First make sure the configuration
   on the PC side matches the one of the Amiga side. For other problems, a full list of beeping codes
   and their meaning is available.

Q: Will Windows 95 run on my A2386SX Bridgeboard?

A: Windows 95 will run on a A2386SX Bridgeboard, although it has been reported
   that the AREAD and AWRITE utilities may not function unless they are used under a real 
   DOS session (not under Windows 95).

Q: Will OS/2 run on my A2386SX Bridgeboard?

A: OS/2 will run on the A2386SX Bridgeboard, however, OS/2 requires almost everything
   to be 'real' (a dedicated mouse, a dedicated hard drive and floppy drive, etc...), otherwise
   the emulated peripherals won't be recognized.

Q: Can I add more than the maximum on-board amount of memory?

A: Yes, but only by using an ISA expansion card that can hold the memory. You must then adjust
   the "Off-board Ext Memory" value in the PC's BIOS.

Q: Can I use some of the Amiga's memory for use by the Bridgeboard?

A: There was a shareware program that was written called AmigaEMS which allowed to use some of
   the Amiga's memory for the Bridgeboard, but it doesn't seem to be supported any longer (no way to 
   register). (See Bridgeboard Tips and Utilities)
  
Q: Can I use the Amiga's serial port for the Bridgeboard?

A: No, only the parallel port is emulated. If you want to use a serial port on the Bridgeboard,
   you'll need to get an I/O board for it.

Q: Can I setup a TCP/IP connection through the shared memory of the Bridgeboard/Amiga to have 
   them 'networked'?
    
A: No such driver has been written (probably due to lack of programming info). It must be done
   the old fashion way: a network.

Q: Can the Bridgeboard have a hard drive/partition that is greater than 500MB?

A: Yes. You will need to setup your hard drive as usual (either a dedicated hard drive or a
   drive partition using JanusTools) and then run a hard drive installation program to format the disk 
   to full size, such as Ontrack's DiskManager (http://www.ontrack.com) or similar program, which is 
   often included with the drive or available from the manufacturer's web site. Once done, you can use
   the drive as usual.
   
Q: Are the Bridgeboards Year 2000 Compliant?

A: As with most older PCs, the A2386SX Bridgeboard is not Year 2000 compliant and will not rollover
   the year correctly. However, it will keep the century information correctly after a reboot; all
   that is needed is to manually set the correct date with the DATE command after the rollover. Please note
   that ATIME will fail with an error "Amiga date not valid for MS-DOS" when the Amiga's date is in the year
   2000, so it will be useless beyond 1999. 
   
   There are a few utilities that fix the Year 2000 problem by monitoring and correcting the date during the
   first boot after the rollover occurs (see Bridgeboard Tips and Utilities).

   For more information on the cause, effects, possible solutions and fixes on this problem, please check
   the Year 2000 Information Center at http://www.year2000.com

   If anyone could do some tests on the XT and 286 Bridgeboards and report back, I would greatly appreciate
   it! (See Contributions)


Content Index Prev Next