Amiga Tower display problems

[Boot_WB]

Is the scandoubler the internal type which clips over some of the chips on the motherboard?  Or an external one?

Are you using some other form of graphics card aswell (eg a Zorro card, or a pci card?)

Does it still sound like the computer is booting from the hard-drive?

Try connecting the (yellow) composite out to a composite in on your TV (a standard phono--phono lead should do the trick).  See if you get a signal from that.  If you can boot into workbench on that you can just reset the screenmode to whatever it was before.

[Boot_WB]

Background (in my limited understanding):

The amiga's native RGB monitor output is at 15.5kHz.  PC monitor frequencies are generally somewhere between 30 and 100kHz.

Original amiga monitors accepted video input at the frequeny the amiga produced - 15.5KHz.  Later 'multiscan' monitors accepted frequencies between around 15.5 and 50 KHz, allowing both PC and amiga to share the same monitor.  Modern PC monitors are generally some range between 30 and 100 kHz, so 'original' amiga screenmodes will not be displayed on them.

The amiga is capable of producing screenmodes at 30khz (-ish), but it takes its toll on processing (and, bizarrely the serial port baud rate).  

Step in the scandoubler, stage left: the scandoubler takes the amiga's native 15.5kHz signal and doubles the scanrate to 31kHz with no extra overhead on the amiga's chipset.

You may know all this already, so apologies if you feel patronised.

To change screen settings:

Go into your workbench drive, prefs drawer, double-click screenmode.  The graphics card you're using in your mediator is a voodoo (3, 4 or 5 - it makes little difference at this point).  
You want to choose one if the screenmodes which start with VOODOO, eg VOODOO:1024x768:32-bit - will give you 32 bit (aka truecolour) 1024x768 resolution through the mediator/voodoo card.  I've found 24-bit (aka high colour) works quite a bit faster, and the colour difference is not really noticable.

If you choose a screenmode labelled with just the numbers (eg 640x320) this will display through the amiga AGA chipset (it will output the video signal through the 23-pin RGB connector next to the composite out port.  If you have a scandoubler attached it should output these 'native' AGA screenmodes through the scandoubler port aswell at twice the frequency, so normal 15.5KHz screenmodes will come out as 31KHz.

There may be other monitor modes available aswell (eg starting with DBLPAL, PAL, NTSC or DBLNTSC): PAL, NTSC you may be familiar with; DBLPAL DBLNTSC are the ~31kHz screenmodes produced by the amiga chipset (as discussed above)  - note these will NOT be doubled to 62kHz by the scandoubler - they will just be passed through.  they will still exact a heavy toll on your chipset though.

Hope that helps, and is not too inaccurate.  

[Boot_WB]

Hi Technium,
Will try and be around a bit today to help.
Don't uninstall or delete anything else just yet!

Firstly, you said you can get to the boot options screen.
Please do that, press the "Boot with no startup sequence" button to get to the command prompt.


Type "c/ed s/startup-sequence" and press enter.

This should list the script which is executed by the amiga as it boots up.  You can edit it here - but for now don't delete anything, don't alter anything.
Ignore any lines which start with a ";" and copy the rest into your next post.

There is probably something in there which is causing an error, preventing your workbench from booting up properly.  We can find out what that is, disable it, and get into your workbench to begin repairs. :-)

[Boot_WB]

Hi Technium,
Looks ok to start, but that's just the start of the file.  Using the cursor keys scroll down the screen - there's  be a whole other load of lines after those.

Also, open s/user-startup and list the lines in that.

Finally, exit the 'ed' program (the text editor) to get back to the command prompt.
Type "sys:wbstartup"
Press enter
Type "dir"
Press enter

List the files which are shown.  Ignore any which end in .info (these are just the icon files, not important at the moment)

I realise it's a pain in the arse and a lot of typing, but hopefully we'll find the root of the problem from this.

Regards


Rich

[Boot_WB]

Hi Technium,

Try changing the line in the startup sequence
DEVS:Monitors/VGAOnly
to
;DEVS:Monitors/VGAOnly

(don't worry about capitals at the moment)

and reboot.

Hopefully you should now be able to get back into workbench and have it displayed through your scandoubler.

I think the vgaonly monitor driver is preventing your scandoubler from doubling the scan rate, whilst not raising the scan rate enough to display on your monitor.

Hopefully this has worked - IF SO READ ON - IF NOT, THE REST IS IRRELEVENT FOR NOW.

Now - go into Devs/monitors  create a new folder called temp - move all the monitor files in the devs/monitors drawer into the new temp drawer.

Once you have done this reinstall picasso96 from your OS3.9 CD (I think it is in the "contributions" drawer).  
Pick the option which does it as a first installation.
Choose Cybervision643d as the graphics card.  

When the installer has finished start the Picasso96 installer again.
Choose 'update an existing installation'
A few screens later a list of installation options appears.  Deselect all the options except 'update monitor type' (or something similar - I think it is the third one from the bottom).
Go through the installation - choose the highest frequency supported by your monitor.

When THAT has finished go into devs/monitors.  
Select the CVision3d monitor file (or whatever it is called).  
Holding down the right mouse button select Icon/information from the menu at the top of the screen.
Click on the ICON tab - In the big box called tooltypes change the entry "card=cvision3d" to "card=voodoo" (it may be 'driver' or something rather than 'card' - I'm doing this from memory)
Click 'save' button.
Rename the 'cvision3d' monitor file to 'voodoo'.
Double-click the new 'voodoo' file icon.

Now - go into prefs & double-click P96mode
Holding down the right mouse button select the 'boards' menu.  There should be an entry labelled 'Board0:voodoo' (or something similar) - select it and release the right mouse button.

If the only entry is 'BOARDS:NONE PRESENT' your voodoo card has not been detected, and we'll need to look at why that is - if this is the case the rest of this post is irrelevent.

Click on SAVE (or save settings or whatever).
P96 mode will tell you it needs to reboot - fine, let it reboot.

When workbench reloads go into prefs:screenmodes

You should now see voodoo screenmodes in the list (I use voodoo:1024x768:24-bit should do the job).

Click the 'TEST' button.  It displays the monitor output through the VOODOO card for 10 seconds - so you have that long to change the monitor cable from your scandoubler socket to the voodoo socket to see if it is working :-).

Once you have a screenmode which you are sure works through the VOODOO click SAVE, exit, reboot (just to be sure the screen initialises ok on bootup).

NOTE: even with the voodoo working you won't be able to see the boot menu using your voodoo card - you'll still need to plug your monitor into the scandoubler.

When this is all done OK let us know - any problems, you know where we are :-)

[Boot_WB]

Hi Colin,

Goddamit! Amiga.org keeps logging me out - every time I think I've posted a reply I have to re-write the damn thing because it hasn't posted!  

Anyway, for now I think the best thing you can do is connect the amiga to the TV to get the software side sorted out.

There are two ways to do this:
1   via the 'composite out' (yellow) port using a phono-phono lead to connect it to an AV port on your tv
2   using the RF modulator (reddish-brown) port (next to the power connector) using a phono-coaxial lead to connect to your TV aerial port and 'tuning in' to the amiga signal.

Obviously no 1 is easiest, but requires your TV has a 'composite in' port.

Once you have done this you should be able to boot into workbench, then follow the instructions in my previous post to reinstall Picasso96 and set up your voodoo screenmode.

Don't know why the scandoubler socket is coming up 'out of range' on your monitor - I have read that some monitors have trouble with low-resolution screenmodes, so this may be why.

By the way - what accelerator card do you have installed?

[Boot_WB]

Hi Technium, I'm going to be with my Amiga today for a couple of hours (we live 60 miles apart at the moment :-(  ), so I'll do some experimenting then.

Will post later this afternoon.

[Boot_WB]

@mugo - the exact solution I'd just come to too :-)

@Colin - Re: nothing actually happens when you double click the icon
don't worry about, that is normal and fine - double-clicking just activates the driver - you then need to go into p96mode, do the changes there, then activate the screenmode.  Just carry on following the instructions on my long post.

Glad you're finally getting somewhere mate.  

[Boot_WB]

Hi Colin, I wouldn't reinstall the OS - without the Multimedia CD you won't be able to install the necessary files to get your mediator up and running.

To reset you should be able to use CTRL+ the two windows keys on your PC keyboard.

In the pciinfo you're looking for an entry for 3dfx.

Another thing to try: look in the libs/picasso96 folder.  Is there a file called voodoo.card (or something similar)?  If not, then I fear uninstalling picasso96 has deleted your P96 voodoo driver.

Unfortunately the voodoo.card driver is not downloadable form the elbox website - you do need the Multimedia CD form this point.

On the off chance, the previous owner MAY have left a backup on the hard drive somewhere, you could try FIND (in the WINDOW menu on workbench) and look for voodoo.card and/or MediatorUP and/or MMCD.

Hopefully you will find one of these on the hard drive somewhere.

[Boot_WB]

HI, yes it appears the driver file (voodoo.card) has been deleted.  P-mail me your address, I believe I have a spare MMCD from a broken mediator which I can mail to you.  Regards  

[Boot_WB]

Hi Technium,
Sorry to hear about the family troubles.  Glad you got the disk ok.

Since you can get the testcard to display when your monitor is attached to the voodoo card this means you are one step form the end of your long journey. :-)

When you have gone into prefs/screenmode and selected one of the voodoo screenmodes, you hit 'test' to make it output to the testcard to the monitor.

There should be many screen sizes listed, eg 1024x768, 800x600, all starting with "VOODOO:".  Once you are happy that the testcard is the right size for your monitor you have two options:

1   Hit 'use' - this will use the selected screenmode until you reboot.  I'd suggest doing this first just to make doubly sure everything is ok.  Your workbench should then be displayed on the monitor attached to your voodoo card.

2   hit 'save' - the workbench will then use this setting every time you reboot (unless something goes wrong during bootup, in which case you can always use the composite port again to find out what has gone wrong).