Pencil II power supply ans écart cable

[xavierm]

Hi,

 

I've found some days ago a hanimex pencil ii in good condition and boxed.

But, without power supply and any cables.

 

I've tried to find informations about pinout but found nothing.

I know that the power supply have 16v and 9v output on a 3 pins din.

 

Some of you have informations about the power supply and the scart cable ?

 

 

 

Thanks for your help.

[wierd_w]

Found one on ebay for 150$. Too rich for a walwart and video cable.

 

However, the detail image shows that the 9v output is 1A, and the 16v output is 500mA.  It uses 240v AC mains input.

 

 

Dunno the pin-out though.

[wierd_w]

Found the user manual. Sadly, no pinouts.

 

https://www.progettosnaps.net/manuals/pdf/pencil2.pdf

 

From what I am finding though, it is basically a glorified colecovision.

[carlsson]

It reminds me a lot about the VTech Creativision power supply that has a 5-pin DIN. However it uses 9V AC @ 1A + 16V AC @ 250 mA which would be devastating to use on a unit that expects DC input.

 

The Pencil II user manual is also here: https://archive.org/details/soundic-pencil-2-users-manual

However it doesn't have any form of pinouts or other technical info that I can find.

 

I also tried to look for schematics but didn't find any after a simple search. Those may be out there somewhere but take more effort to find. One way might be to take it apart and study the leads coming from the power connector. If there is one or more pins connected to vast fields of area that almost everything else also is connected too, that may be ground unless it is some odd design that has voltage everywhere. Further I would look for things such as 7812 and 7805 voltage regulators, assuming it converts those 9V + 16V into 5V and 12V. If you can find such circuits near the power connector, it could be traced back which pin holds the input voltage. After checking the manual, I realize that the connector really only has 3 pins, which should make it easier to distinguish which is which.

 

There may be better ways to do it, but that is what I'm thinking of.

 

Video cable probably is easier. I see that is another DIN that carries composite video and mono audio. You could get a pigtail with one 5-pin DIN (assuming it is this variety of pins) and four RCA jacks and then try one by one until you get an image, then use the other for sound. I wouldn't be surprised if it is compatible with e.g. Sega Master System & Genesis, or possibly compatible with Atari 8-bit, VIC/C64, TI-99/4A, SVI-328 (all those have the basic pinout in common, though finer details differ). In an extreme case, the Pencil II might have ground on a different pin than the standard but let's not expect the worst. Once you have wired up a cable with DIN to RCA, you can use a passive adapter to get SCART unless you want to order a special cable that goes directly from DIN to SCART. If you find that it matches either of the two types of pinouts I mentioned, it is easier to find a cable for this purpose.

 

Edit: I checked the manual more closely and the video connector is a 7-pin DIN. Unless it carries Y, B-Y, R-Y (*) as well as composite video, it seems a bit wasteful to have 7 pins for 2 signals + ground.

 

(*) The VDP 9918/28/29 series does not natively output RGB, but this kind of component video. Additional circuitry is used on some other models to convert it into a RGB signal. Certainly the Pencil II might have such additional circuitry as well, but I haven't found any evidence in either direction.

Edited June 10, 2021 by carlsson

[wierd_w]

The european version of the TMS9918/9928 is able to produce component video.  It was used in the PAL version of the TI 99/4A.   This computer was principally sold in Europe, and thus likely is using this PAL variant of the chip.

 

Found an interesting pic of the interior of this system.  I cannot identify the video chip due to the heatsink being present on the VDP, however, the number of video leads is telling.

 

 

Some of the internal voltages are silkscreened on the system board on the AV cable that leads to the video logic sub-board at the left. 

 

Some scrutinizing of the colors of the wires on the power plug suggests that right-most pin (since we are looking at the back side of the port here) is +5v (+9v), bottom pin is +12v (+16v), and leftmost pin is GND.

DO VERIFY BY LOOKING AT THE UNDERSIDE OF THE VIDEO/POWER BOARD.

Edited June 10, 2021 by wierd_w

[carlsson]

Yeah, since Hong Kong was a UK province it makes sense it is PAL. Also mainland China is PAL, perhaps a few more countries.

 

Interesting that every signal on the NEC D780C-1 (Z80) is silk screened and some signals from the other chips as well. So the power, video/TV and cassette is on one board and the main part of the system is on another, with 9+5 wires connecting the two. I can't spot any 7805 or 7812 but there were other ways to convert voltages. It would be very convenient if the same colours for the wires were chosen as later Molex etc use but it probably can be traced with some skilled work.

[wierd_w]

The biggest risk factor when using a commodore/ti video cable is where the +12v lead is on the DIN.  Since we have a nicely labeled +12v lead going to the video sub board, a multimeter test can be used. (+12v is used to power an external RF modulator, if needed. For plainly obvious reasons, that should not be put through a composite video circuit.)

 

Additionally, composite video is well labeled also. Continuity testing should give those also, along with audio.  So, getting video pinout should be a short process with a multimeter.

 

Power is the straggler.

Edited June 10, 2021 by wierd_w

[carlsson]

True. The European TI-99/4A uses a 6-pin DIN while this one as a 7-pin so just like I suggested it might have all the signals of the PAL 99/4A + composite video which only exists on the NTSC 99/4A. It'd be interesting to find out of the pins for ground, composite video and audio follow the Atari/Commodore/TI/SVI variant, and the remaining 4 pins are used for the component signals and perhaps one with a voltage or not connected.

[carlsson]

The 4066 CMOS on the power board might be helpful. It takes 5V on pin 14 (upper right checking the notch). Backtracing the traces on the board would tell how that voltage was generated, hopefully leading back to the three pin header on the board with the wires to the power connector.