Times Sinclair 1500 video out

[PokeMon]

Where is Maryland ?

[sirmorris]

@Jegs - aah I suspected you were in the US. If you were in the UK there would have been more options that I know of.

C

[gozzo]

Just to warn about using 'small' screen LCD tv's with 'vintage' computers - you may find that some horizontal lines are 'missing' - that's what happened to me when I tried a 7 inch colour LCD tv with a VIC20 when testing it(the VIC, that is) - it worked ok with a larger (17 inch) LCD tv and a normal CRT type - not sure of the exact reasons for this but I think it may be because the vertical resolution of the TV is lower than the number of lines in the video signal being fed to it..larger screens would have more pixels so don't give this trouble (usually..??) ..????

[PokeMon]

Maybe this is caused through display settings.
For 16:9 format TV's (expect your small LCD is one) you can choose what to do with old sized (4:3) video signal, default maybe zoom.
This will reduce borders left and right but cut the picture on top and down.
So not sure if you tried this to change.

If I choose zoom on my plasma I can't see the first line of ZX81 screen but if I change from display format zoom to 4:3 or widescreen the picture is seen in full size (but "stretched" with widescreen option). Also have an option "smart" which is a combination of widescreen and zoom.

[angus]

You may also find that smaller (pocket and 'car') screens do not offer the full resolution, not even 576 horizontal lines. Some of the cheaper LCD screens designed for pocket TV viewing or kids watching DVDs in the car have resolutions under 400 lines.

With such a screen you may well find bits appear to be 'missing'...just like taking a projector with native 800x600 resolution and pushing a 1024x768 signal to it....or a 1080i signal into an "HD Ready" 720 television. It looks OK for a picture but for text sometimes scan lines aren't shown correctly.

[jegs2]

Sorry for the ancient thread bump, but tried this mod on my T/S 1500 last week, and I've got no video at all now.

Any ideas? If necessary, can send a pic of my mod. To be fair, it was my first ever home-made circuit attempt, so there's that.

[1024MAK]

Pictures would indeed help. If using a camera, if possible use macro mode.

Which transistor did you use?

Do you have a multimeter?

How are your soldering skills? If this the first time you have used a soldering iron for electronics, or do you have some experience?

Mark

[jegs2]

Back of Circuit.JPG (92.31 KiB) Viewed 5415 times

My electronics capabilities are beyond laughable, but below is my attempt, which obviously failed to meet its intent:

Overall Snapshot of Video Mod for TS 1500

Snapshot of Mod.JPG (153.44 KiB) Viewed 5415 times

Front of Circuit.JPG (41.32 KiB) Viewed 5415 times

All I get is a steady gray screen on the input now. Like the steadiness, but would really like to see the K there too.

[jegs2]

Just saw this on a related video issue thread, and since a fellow user used the mod on a TS 1500, will be ordering two of those (I'll find a way to mess up one of them, I just know it) to install in my own machine.

Only sad-face right now is that the site keeps crashing when I try to register to order.

[rune]

I've just ordered my 4th one. They are excellent and Im slowly getting a brace of ZX81s back working again.