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No colour video from Apple II Europlus

Hello,

I have another problem with my Apple II Europlus.  It will not output
colour video.  Everything is in black and white, but dithered.  I have
tried with PAL (as should work with the Europlus) and NTSC.

There is a Kaga-Taxan RGB card installed.  Could that be interfering?
I have tried with it removed from the slot, but not removed entirely
because there is a wire from it connected to one of the chips on the
motherboard that I am yet to desolder.  I have played around with the
variable capacitor on the motherboard as well that is supposed to
adjust hue, but it makes no difference.

Any thoughts on what to check?

Thanks

Ken

0
ken.wessen (38)
5/18/2006 11:51:22 PM
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Kallikak wrote:
>
> I have another problem with my Apple II Europlus.  It will not output
> colour video.  Everything is in black and white, but dithered.  I have
> tried with PAL (as should work with the Europlus) and NTSC.
>
> There is a Kaga-Taxan RGB card installed.  Could that be interfering?
> I have tried with it removed from the slot, but not removed entirely
> because there is a wire from it connected to one of the chips on the
> motherboard that I am yet to desolder.  I have played around with the
> variable capacitor on the motherboard as well that is supposed to
> adjust hue, but it makes no difference.
>
> Any thoughts on what to check?
>

If I recall, the Europlus logic board can't output color video by
itself, there was a card which was needed to generate the PAL color
signals.

Tom

0
tom5049 (47)
5/19/2006 12:29:42 AM
> If I recall, the Europlus logic board can't output color video by
> itself, there was a card which was needed to generate the PAL color
> signals.

AFAIK this is the card type that should work:
http://cgi.ebay.de/Apple-II-PAL-encoder-video-card_W0QQitemZ8812676082QQcategoryZ4601QQrdZ1QQcmdZViewItem

bye
Marcus

0
5/19/2006 4:16:44 AM
Yes,

It seems that Tom is right, and the NTSC hack that gives colour smiply
doesn't work with PAL, and the Europlus PAL adjustment is really only
an adjustment of the frequency down to 50Hz.

I've been watching that ebay link, but pretty much everything that guy
has been selling is being bought by one person who seems to be
unhindered by such mundane concerns such as cost!  :-)

So my question is now, does anyone have specific details for switching
the Apple II back to NTSC?  There are some soldered jumpers that need
to be changed - that's no problem (as long as I know which ones), but
if it also needs an oscillator changed, I may have more problem finding
an appropriate part.

Ken

0
ken.wessen (38)
5/19/2006 4:31:16 AM
Kallikak wrote:
> It seems that Tom is right, and the NTSC hack that gives colour smiply
> doesn't work with PAL, and the Europlus PAL adjustment is really only
> an adjustment of the frequency down to 50Hz.

Yes, I agree as well.

> I've been watching that ebay link, but pretty much everything that guy
> has been selling is being bought by one person who seems to be
> unhindered by such mundane concerns such as cost!  :-)

I think I have a spare PAL color card if you want one.

> So my question is now, does anyone have specific details for switching
> the Apple II back to NTSC?  There are some soldered jumpers that need
> to be changed - that's no problem (as long as I know which ones), but
> if it also needs an oscillator changed, I may have more problem finding
> an appropriate part.

Revert jumper changes to change number of scanlines from 312 (PAL) to
262 (NTSC).
Change main oscillator crystal from 14.25MHz to 14.18318MHz to change
horizontal scan rate from 15625Hz to 15725Hz.
That should be it.

0
mcs6502 (519)
5/19/2006 6:17:10 AM
> So my question is now, does anyone have specific details for switching
> the Apple II back to NTSC?  There are some soldered jumpers that need
> to be changed - that's no problem (as long as I know which ones), but
> if it also needs an oscillator changed, I may have more problem finding
> an appropriate part.

I have no details for the II/II+ but I did this on a IIe and it should
work *if* your TV set / monitor supports NTSC. It has an additional
advantage: The picture gets "unsquashed" and fills (nearly) the whole
screen. No thick PAL borders anymore.

Of course you could buy a genuine NTSC board on ebay for around $10
(they usually are at a fixed price) or from some American dealer...

bye
Marcus

0
5/19/2006 2:11:31 PM
> Of course you could buy a genuine NTSC board on ebay for around $10
> (they usually are at a fixed price) or from some American dealer...

I'm probably somewhat over-enthusiastic here - IIe mainboards go for
this price (plus shipping) but II/II+ boards are not that frequent on
ebay.

bye
Marcus

0
5/19/2006 2:52:53 PM
Kallikak wrote:
> Yes,
>
> It seems that Tom is right, and the NTSC hack that gives colour smiply
> doesn't work with PAL, and the Europlus PAL adjustment is really only
> an adjustment of the frequency down to 50Hz.

It should be noted that this applies to all Apple II models, not just
the II/II+. No Apple II can produce a correct PAL signal straight from
the motherboard

The only model that even attempts it is the european beige IIe. The
composite out on this motherboard produces a 50Hz signal that displays
colour, but when this output is connected to the AppleColour Composite
display, the colours come out all 'wrong'

To get around this, in the Australian market a modified version of the
extended 80 column card was produced that output an excellent PAL
signal. It was even 'fringe free' ! This card was the reason that the
auxiliary slot is relocated on european IIe's to be inline with slot 3.
A major annoyance to IIe power users. The circuitry on this card is
very similar to what's contained in the IIc RF modulator, sans
modulator.

The platinum european IIe outputs 50Hz NTSC, just like every other
european Apple II. The colour cards still work in these machines but
became unavailable because the AppleColour Composite display is capable
of producing the correct colours when fed a 50Hz NTSC signal.

Of course, the IIgs can be switched between 50 and 60hz operation by
holding down the option key during power on.

I've never tried one of the original PAL cards in a IIe or a IIgs to
determine if the signals are even present on the slot; they were only
present on slot 7 in the original Apple II anyway. If it works, it's
probably the only way to generate a PAL signal from a IIgs using
standard components.

Matt

0
mdj.mdj (1102)
5/20/2006 5:08:13 AM
> It should be noted that this applies to all Apple II models, not just
> the II/II+. No Apple II can produce a correct PAL signal straight from
> the motherboard
>
> The only model that even attempts it is the european beige IIe. The
> composite out on this motherboard produces a 50Hz signal that displays
> colour, but when this output is connected to the AppleColour Composite
> display, the colours come out all 'wrong'

I won't define this monitor to judge "correct" PAL signals.

My PAL IIe board from a French IIe (made 1984) outputs "correct" colors
on a standard TV set. My only gripe with the picture is that it is
"squashed" because of the higher linecount of the PAL system.

> To get around this, in the Australian market a modified version of the
> extended 80 column card was produced that output an excellent PAL
> signal. It was even 'fringe free'

The above mentioned PAL board has this feature, too.
Most noticeably in the text window of a mixed graphics mode.

> The platinum european IIe outputs 50Hz NTSC, just like every other
> european Apple II.

No surprise - it uses an "International NTSC" board. Which outputs a
travesty of a video signal (NTSC at 50 Hz) - which is even worse than
PAL at 60 Hz.

> The colour cards still work in these machines but became unavailable because
> the AppleColour Composite display is capable of producing the correct colours
> when fed a 50Hz NTSC signal.

A good sign that this monitor has some creative understanding of video
standards.

bye
Marcus

0
5/20/2006 7:47:24 AM
heuser.marcus@freenet.de wrote:

> My PAL IIe board from a French IIe (made 1984) outputs "correct" colors
> on a standard TV set. My only gripe with the picture is that it is
> "squashed" because of the higher linecount of the PAL system.

Interesting. I had assumed that the IIe motherboards sold in Australia
were the same as in Europe - perhaps I am mistaken. Any chance you
could send a photograph of the mainboard?

Matt

0
mdj.mdj (1102)
5/20/2006 10:48:44 AM
> Interesting. I had assumed that the IIe motherboards sold in Australia
> were the same as in Europe - perhaps I am mistaken. Any chance you
> could send a photograph of the mainboard?

I'll see what I can do! May take a day, though.

bye
Marcus

0
5/20/2006 12:14:36 PM
Ha! I knew I had photos from the restauration of the mainboard!

Probably some solvent or acid was spilled over the right half of the
keyboard and got onto the mainboard. I couldn't save the keyboard but
after desoldering the chips and socketing them the board was up and
running.

There is one beautiful shot of the video section so I guess you can
compare it easily.

Additionally, I included some screen shots of this board to better
compare it with NTSC on the same TV set (Loewe Arcada).
These were taken with a 3 megapixel camera in a darkened room and show
a distinct moiree pattern that is not visible on the screen!

Download the zip-archive here (13,8 MB):

http://rapidshare.de/files/20927237/ApplePics.zip.html

bye
Marcus

0
5/20/2006 12:52:51 PM
heuser.marcus@freenet.de wrote:
> Ha! I knew I had photos from the restauration of the mainboard!
>
> http://rapidshare.de/files/20927237/ApplePics.zip.html

Very interesting. My beige PAL IIe motherboards look like the same
layout and components (including the absence of C77 and R33) but have a
different part number silk-screened near the RED LED at the rear of the
board - my two are both 607-0264 [one is silk-screened and the other
has it typed/printed on a paper label].

I know that the color on mine is only so-so (when compared to the NTSC
on my MPF-III (a IIe clone)). I wonder if the trimpots near the 4.43MHz
crystal need tweaking.

0
mcs6502 (519)
5/20/2006 2:43:10 PM
David Wilson wrote:

> I know that the color on mine is only so-so (when compared to the NTSC
> on my MPF-III (a IIe clone)). I wonder if the trimpots near the 4.43MHz
> crystal need tweaking.

Just set the screen to all black (lores or hires, not text mode) and 
turn the pots until the screen is not tinted any more.

You can also try adjusting trimmable cap. It mainly controls the amout 
of moire you get. In truth you always get fairly strong moire from this 
motherboard, but with the pot you can get it to move so fast as to be 
almost invisible -- I can still catch it in the corner of my eye but not 
if I look straight onto the screen.

But of course if this cap is heavily deadjusted, colors will be bad as well.

All the Euroapples that use this kind of PAL encoder have the property 
that the color signal is only changed once every four double-hires 
pixels (or once every two hires pixels). This can sometimes mess up 
vertical edges a bit, as it's not a true "sliding window" implementation.

-- 
Linards Ticmanis
0
ticmanis (776)
5/20/2006 8:49:52 PM
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