Times Sinclair 1500 video out

[jegs2]

Alright, so the video out device arrived, which is cool.

Now, I've got to figure out how to install it on my TS 1500.
It does come with instructions, but they're for a ZX81, and I'll surely find a way to screw it up, seeing as how I've still never successfully modified anything electronic.


PS: Does the device negate a need for the RF adapter ... i.e. once it's installed, can you plug the machine directly into the video-in port on your friendly TV?

[rune]

Alright, so the video out device arrived, which is cool.

Now, I've got to figure out how to install it on my TS 1500.
It does come with instructions, but they're for a ZX81, and I'll surely find a way to screw it up, seeing as how I've still never successfully modified anything electronic.


PS: Does the device negate a need for the RF adapter ... i.e. once it's installed, can you plug the machine directly into the video-in port on your friendly TV?

Hi, the best way on the ZX81 is to locate the two wires going into the RF modulator. One is 5V the other is signal. If you are keeping the RF Modulator or testing connect the input red (5V)/yellow(signal) to these and the black to a suitable earth. The other two wires go to a composite socket.

If you are replacing the RF modulator, desolder it and remove the innards. Reattach the casing to the board, insulate the bottom with a piece of card or something and sit the new unit inside. Bring the 5V and signal wires through the side and solder to the ZX81 board where the original inputs came from. Use the inner wall of the case as earth and the orange composite wire to the centre pin of the TV socket.

Tune it in , pop the lid back on and you wouldn't know it was there.

[jegs2]

Thanks, those are great detailed instructions for the ZX-81, and the instructions shipped with the device include a picture of where to put wires, for folks like me.

Unfortunately, my unit is a TS-1500, so the instructions are minimally useful.

[Moggy]

A schematic can be found here in the download section....

http://www.zx81.de/webring/index.htm

Not the best quality but should be useful.

[PokeMon]

Actually I am not very familiar with the TS1500 - but you can get +5V (red) from Pin 11 of Z80 CPU and GND (black) from Pin 29 of Z80.
Can see picture of IC here:
http://www.z80.eu/z80pin.jpg

Please check number one pin and if soldering from solder side check for eventually mirrored pin out.
The yellow cable (video in) can be connected directly to the modulator in, the middle pin.

The output orange and black can be soldered to a video/RCA jack (chinch) whil black is GND (outer signal) and orange inner signal.

[jegs2]

Thanks. I'll try that out.

[jegs2]

Okay, so got the job mostly done (soldering-wise anyway), except for the following, which confused me:

The output orange and black can be soldered to a video/RCA jack (chinch) whil black is GND (outer signal) and orange inner signal.

Not sure where to find that. Here are some pics of what I've done. If you can point out where I'm supposed finish, I'd be grateful.

[1024MAK]

The input to the new ZX8-CCB video circuit (the yellow wire) needs to be connected to the video output of the "ULA" chip. On the TS1500, the "ULA" is the square surface mounted chip.

One place to pick up this signal is on the anode leg of diode D19. You want the solder side of the board, and the diode connection nearest the crystal (the crystal is in the metal silver can that has two connection leads next to the diode, the identity on the PCB for the crystal is "X1").

The output (orange wire) from the new ZX8-CCB video circuit needs to go to a RCA / phono / chinch connector (known by different names in different parts of the world).

The orange coloured wire is the video signal and either one of the black wires connects to the 0V/ground/shield.
Connect the orange coloured wire to the inner pin and connect the black wire to the outer / sleeve connection.

For testing, for now, I would buy an in line cable socket and use that. Later once you have it working, you can decide if you want to have a composite video output socket (and keep the RF output), or if you want to disconnect the RF output and wire the composite output in it's place.

If you follow my instructions above, and do not make any connections to the modulator or it's output socket. Then the modulator and it's RF output should still work (remove any connections that you have already made to the modulator and restore it to how it was originally).

Note that as the new ZX8-CCB video circuit has been set for for a ZX81, both variable resistors (presets) will need to be carefully set up.

I hope this helps.

Mark

[jegs2]

I put it together as recommended, and from that output I get only a dark screen.

To see if my computer was still functional, I did hook up the video to the TV-out, and got the usual crappy picture with full functionality.

So, don't know where I went wrong. Pics are forthcoming.

[jegs2]

As for the RCA Jack, connected the black wire to the outside (jacket) wire, and the orange one to the center wire.