Apple II europlus has no color !

[Cyprus66]

Hello Vintage Computers Forum,

This is my second restoration project , on an Apple II Europlus I purchased a few months ago on eBay, sold as "untested for parts." I've been spending a few weekends carefully restoring this iconic computer.

I encountered a few problems along the way:

Astec SMPSU recap:
The Astec switching power supply needed recapping — the infamous "time bomb" RIFA capacitors were replaced. After servicing, I tested all output voltages and found them within tolerance.

Keyboard cable damage:
During the restoration and cleaning process, I accidentally damaged the keyboard cable connecting the motherboard to the encoder PCB. Unfortunately, while trying to straighten two bent pins, they snapped off, rendering the connector useless.
After some hunting, I found a company called Digi-Key that supplied a pre-made 16-pin DIP cable. After a short wait for delivery, I fitted the new cable, carefully checking the correct polarity for GND and +5V.
Last week, I finally found some time to assemble and test everything.

To my delight, the unit powered up with the famous single beep from the Apple II Europlus !

I immediately powered up my Siglent 100MHz oscilloscope and observed both the sync signal and the composite video output.
I connected the video via a good quality 75-ohm RCA cable to my LG LCD screen (which has a composite input).
Once again, to my delight, I saw the Apple II prompt! I quickly ran a few programs to check CPU functionality — all worked well.

However, when testing for colour output, I only get monochrome.

Since this is a Europlus model, my understanding is that it was modified for PAL video standards and fitted with a 220–240V power supply.
I suspect the issue might be with my LG TV, which may not properly decode the slightly non-standard PAL composite signal from the Europlus, defaulting to black and white.

Any thoughts or workarounds would be appreciated — I would love to see it generating colour properly!

[ortek_service]

I always thought that the Apple II was Monochrome as standard, but wasn't sure about the Europlus.
However it seems it is a bit more complicated in that whilst the original USA NTSC version was 'Color', when they modified it for PAL for use in Europe, it was only Monochrome! - And you needed an additional PAL Colour card:
https://www.computinghistory.org.uk/det/1334/apple-ii-europlus/


Although this info seems to suggest you needed a special colour monitor (to work with ones sold in New Zealand at least?):
https://www.applefritter.com/content/apple-ii-europlus-ntsc-colour

BTW, you can normally buy those IDC ribbon cable DIL headers in the UK, and (re)make your own cables. You just need a plastic etc spacer or a dummy IC socket etc to protect the pins when crimping these up in a vice etc (unless you have the hand crimp tool for doing these / standard 'DIP' IDC socket-connectors).

[TonyDuell]

I seem to remember that the 'Europlus' modifications involved some jumper pad changes and a different clock oscillator crystal. The result was 50Hz video timing, but still essentially an NTSC-encoded colour output.

There was an Apple PAL encoder board and at least one third-party RGB decoder. These went in slot 7 (furthest from the power supply) and also picked up the video from the 4 pin modulator connector (or the single pin alongside it) on the motherboard.

[SiriusHardware]

I'm surprised the modern? LG doesn't simply go 'Oh, that's an NTSC signal' and adjust accordingly but maybe the 50Hz frame rate is training it to expect a PAL colour signal.

There are a lot of '...to HDMI' converter boxes around now, they are as likely to be able to recognise and convert an NTSC encoded signal as they are a PAL encoded signal, perhaps more so given that the USA is probably the primary market for such gadgets. so maybe look at some of those - probably cheaper than an original Apple PAL card.

It's a shame it doesn't have RGB-out as that bypasses any notion of PAL or NTSC, it will work as long as the display is happy to work at either 50Hz or 60Hz framerate. The quality is always better as well.

[SiriusHardware]

Just been reading around, one post mentioned that the Europlus has 'Component' out which was the common USA alternative to the much more sensible (IMO) RGB favoured in Europe.

We would call 'Component' video 'YPbPr'. Despite the RCA connectors for 'Component' video being coloured red, green and blue they do not carry separate Red, Green and Blue intensity information as in RGB, but rather a luminance signal and two colour difference signals. Green is 'Y', Blue is 'Pb', Red is 'Pr'.

This complication is not something you need worry about - if the Apple has 'Component Out' and your TV has 'Component In', just connect one to the other.

A lot of TVs of a certain age do have 'Component' inputs alongside their other input options, does yours?

[TonyDuell]

I am not aware of any 'component video' output on the Apple ][ Europlus. I wonder if it's a misprint for 'composite video'. (As an aside, the Tatung Einstein _does_ have selectable component or RGB video outputs).

The NTSC colour on the Apple ][ was produced almost as a byproduct of the video display circuitry. There is no point where there are RGB or equivalent signals, unlike most computer colour displays.

[SiriusHardware]

I am not aware of any 'component video' output on the Apple ][ Europlus.

That's a shame - in that case probably a standalone composite-to-HDMI box is the way to go - just check that it can work with NTSC as well as PAL composite input signals.

[TonyDuell]

I wonder... There is no separate NTSC subcarrier crystal in the American Apple ][, the subcarrier comes from dividing down the main clock crystal. The Europlus modification involved cutting some pads on the PCB, blobbing solder across others to change the video timing to get the right number of lines/picture. It also involved changing that main clock crystal to one of a similar frequency.

Which means, I suspect, that the subcarrier on the output of a Europlus is not 3.57MHz but something 'off'. So it wouldn't surprise me if NTSC-compatible monitors/converters won't lock to it. The Apple PAL board and the RGB decoders I've come across picked up multiples of the actual subcarrier from slot 7 so presumably used that as the reference.

[SiriusHardware]

It sounds as though converting it properly 'back' to USA standard 60Hz / NTSC output would ironically be a step in the right direction at least as far as improving the ability of modern displays and converters to work with it goes.

[SiriusHardware]

This company here:-

https://www.a2heaven.com/webshop/

Appears to be to Apple II what Tynemouth Software was to PETs.

They have a huge current range of gizmos and add-ons including VGA-out and RGB-out options but of course they are in the USA and their items are not cheap - and that's not even counting the cost of getting them posted to the UK, assuming they will supply to the UK. And given what Tony said about clock frequencies, you'd have to check with them whether they can be expected to work in a Europlus.

[TonyDuell]

That shouldn't be too hard. You'll need the Apple ][ reference manual of a sufficiently late edition to cover the modifications.

Basically, you will see some solder pads on the motherboard that consist of 2 semicircles with a blob of solder shorting them. Remove the solder and clean those up so they are open-circuit. You'll also see some 'X' or diablo-shaped ones that have been cut at the narrowest point. Solder across those so they are connected.

Replace the crystal which I think is 14.25MHz in the Europlus with a 14.31818KHz one (4*NTSC subcarrier).

I think the subcarrier on the Europlus is around 3.56MHz, just far enough away from the correct value that most things won't lock to it.

[ortek_service]

From that CfCH article I previously linked-to:

After the success of the first Apple II in the United States, Apple expanded its market to include Europe and Asia in 1978, with the Apple II Europlus (Europe) and the Apple II J-Plus (Japan).
In these models, Apple made the necessary hardware, software and firmware changes in order to comply to standards outside of the US.
The power supply was modified to accept the local voltage, and in the European model the video output signal was changed from colour NTSC to monochrome PAL — an extra video card was needed for colour PAL graphics, since the simple tricks Wozniak had used to generate a pseudo-NTSC signal with minimal hardware didn't carry over to the more complex PAL system.

So it seems to me that the Europlus was PAL (rather than NTSC) as standard, and that it was actually mono as standard
- So you needed an extra PAL Colour graphics video card (not originally fitted by default?) for that.
And I presume the OP's one doesn't have this fitted?

Although it might be possible to reverse the mods on a Europlus back to the USA NTSC Colour version, depending how they did these (Maybe a different mainboard PCB, rather than just changing oscillator frequency etc.?) and use an NTSC compatible monitor / converter to HDMI etc.
Although may also need to change the firmware back to the USA version?

[SiriusHardware]

Tony seems to think it's doable (his post #11). Sounds reversible, as well, if it doesn't work.

[julie_m]

There is no NTSC encoder in an Apple ][. It relies on a trick based on the properties of the NTSC system instead. Basically (and I'm sure the colour telly people will be along to point out any mistakes I'm making), a narrow white pulse with sufficiently fast rise and fall times will break through the colour subcarrier filter and appear as some colour, depending on its timing relative to the colour subcarrier. A grating of vertical "white" lines will appear as one colour if all the lit pixels are in even positions, and its negative if all the lit pixels are in odd positions; and two sets of pixel timings so you can have either magenta and green, or blue and orange in any scanline of any character cell. Two or more contiguous lit pixels show white.

This doesn't translate well to PAL because there are an odd number of half-lines in each field, and each parity of field can start on an odd or even phase, which accounts for the characteristic four-field dot crawl sequence.

NTSC-to-HDMI converters can pick up on deliberate attempts to create colour using artefacts and convert to neat solid colours.

[SiriusHardware]

To summarise then:

-Europlus machines do not even attempt to output a PAL colour signal, so they can not be expected to produce a colour picture on a PAL-only display.

-Due to the timing changes to make the machine put out a 50Hz framerate instead of 60Hz the timing of the NTSC colour signal is no longer correct, so even a display capable of working with NTSC may not be able to get a colour lock on this 'altered NTSC' output. There is a suggestion that one of the various currently available 'composite - to HDMI' converter boxes might be able to interpret this 'altered' NTSC signal correctly and still produce a colour display, but this would have to be tried.

-It might not be too hard to reverse-mod the machine to its original 'true' NTSC configuration to allow original NTSC compatible displays to work with it, and any such mod seems easily reversible, so could be tried and undone if it does not work.

-There are internally installable display-out options such as VGA-out and RGB-out and PAL-out available even now, although they tend to be expensive and maybe only available from the USA.

[cmjones01]

I can confirm all this from experience. Long ago I had both Apple ][ Europlus and Apple //e machines, UK market models, and neither of them generated PAL colour outputs. They just gave the patterns of stripes which would have been NTSC colours. I didn't have an NTSC colour monitor at the time so I don't know whether it would have shown colours.

If I remember correctly the 'official' PAL colour encoder for the Apple II series uses some trickery with a state machine to do a sort of digital-domain decoding of the NTSC colours, which results in a component video output (possibly even RGB) which is then re-encoded into PAL. As Julie said earlier in the thread, the component or RGB signals are otherwise not present anywhere in the Apple II's circuitry because of the cheap-and-cheerful way it generates an NTSC colour video signal.

Chris

[Cyprus66]

Thank you all for your feedback on my query regarding the lack of colour output from my Apple ][ Europlus when connected to an LCD screen via a component (RCA) input. I truly appreciate the insight and support you’ve provided.

I’m still getting my head around Apple II-specific hardware and configurations! Growing up in the UK during the late 70s and early 80s, Apple computers were unfortunately out of reach for me — far too expensive for a 14-year-old surviving on paper round and Saturday job wages.

Based on the helpful responses from Tony, SirusHardware, Ortek Service, Julie M, and finally cmjones01, I now understand that the Apple ][ Europlus (the UK market model) does not generate a PAL colour output. I also appreciate the explanation that the Apple II’s design doesn’t provide component or RGB signals, largely due to the “cheap and cheerful” way it produces NTSC colour video.

After exploring possible legacy conversion options — and realizing the added complications from crystal oscillator clock mismatches — I decided to invest in a more practical solution for use with modern displays.

I have now purchased an APPLE II, II+, IIe DVI/HDMI Graphics Card (A2DVI). As quoted:
“This card auto-detects your machine and works with an Apple II, II+, or IIe without any modifications. It directly generates a digital video stream from the Apple II’s memory content. The signal is output via an HDMI connector, allowing easy connection to modern displays with HDMI inputs. No more analog signal conversion required.”

Thanks again, everyone, for helping me on this journey. Your knowledge and advice made a big difference!

[SiriusHardware]

Sorry we were the bearers of bad tidings, in so far as it wasn't just a matter of a quick, cheap fix.

Don't go just yet though, when you get that video-out card fitted and working round off with a little demo / review so we can see what it looks like working, and let us know if it 'just works' or you need to do any fettling. This is all very useful info for anyone who surfs onto this thread in the future.

Interesting little PCB - appears to be 90% Raspberry Pi Pico - I would guess the ICs on the carrier / adaptor PCB are just logic level converters, since the Pico is a 0V-3V3 logic device and of course the logic voltages in the Apple will be 0V-5V.

[SiriusHardware]

More about the A2DVI project here:-

https://github.com/ThorstenBr/A2DVI-Firmware

[ortek_service]

Thanks for the info / link.
Good to see that A2DVI is Open-Source and hardware is fairly-simple using an RPi-Pico module and an adaptor PCB with 4 buffer/level-converter? IC's to the Apple II bus connector. So can presumably just buy the blank PCB, and construct one (or maybe get one ready-assembled, if preferred).

I've unfortunately not yet had an Apple-II, although had acquired the odd interface for one.
I do recall a friend having one in the the 80's, and someone at work had been selling one for £15 back in the 90's which regrettably I didn't buy
- as it no-doubt costs rather-more to get one and I don't think I've ever seen one for sale at Radio Rallies etc that most other 80's computers were previously being sold at.