How to tell which ULA

[DonLafferty]

I got a TS1000 from Ebay and decided to do the composite mod but everything I read says it depends on your ULA as to which mod to do.

Thankfully the previous owner put a heat sink on the ULA but of course that means I don't know which one it is.

Is there an easy way to tell without pulling the heat sing off?

Thanks

[1024MAK]

Hello and welcome to our forum

Is it in a socket? If yes, then the earliest type will have a type number on the underside (unlikely to have an early type in a TS1000 though). If you have never removed a chip from a socket before, please ask for help. Bent or broken pins are not a good thing on chips that you can no longer easily get.

Otherwise, it’s not easy to tell without doing some electrical testing with the correct test equipment (‘scope).

However, it’s not necessarily a problem. Get a ZX8-CCB video module. That can cope with all ULA versions.

Or you can try it on the RF output with a TV and see what happens (assuming you still have a suitable TV).

Mark

[DonLafferty]

Hello and welcome to our forum

Is it in a socket? If yes, then the earliest type will have a type number on the underside (unlikely to have an early type in a TS1000 though). If you have never removed a chip from a socket before, please ask for help. Bent or broken pins are not a good thing on chips that you can no longer easily get.

Otherwise, it’s not easy to tell without doing some electrical testing with the correct test equipment (‘scope).

However, it’s not necessarily a problem. Get a ZX8-CCB video module. That can cope with all ULA versions.

Or you can try it on the RF output with a TV and see what happens (assuming you still have a suitable TV).

Mark

It is in a socket. As I mentioned in my intro post I'm an RF engineer and have been working on hardware since the 80s so removing a chip from a socket doesn't bother me.

Somebody on Facebook suggested looking at the signal to see if there's a back porch and if it's there then it's the later chip. I was going to try that later today.

Do you have a link to where I could purchase this ZX8-CCB module? I've had trouble finding anyone who sells things like that for the TS1000 family but perhaps because I'm not persistent enough.

Thanks for your suggestions!

[DonLafferty]

I pulled it out and the number was on the back. It's a 2C184E so I assume that means it has no back porch.

[Lardo Boffin]

USAJoe posted buying the ZX8-CCB on Etsy here:

https://www.sinclairzxworld.com/viewtop ... f=7&t=5026

I thought I saw a link somewhere but can’t see it.

[1024MAK]

This is the web site that the developer of the ZX8-CCB has set up. The operation is based in Germany.

USAJoe posted buying the ZX8-CCB on Etsy here:

https://www.sinclairzxworld.com/viewtop ... f=7&t=5026

I thought I saw a link somewhere but can’t see it.

The link to the (I assume) reseller on Etsy is in this post.

There is more information on the different ULAs on the forums, click the link in my signature below.

Mark

[USAJoe]

I have the same ULA in my 1000. I'm still waiting for the delivery of my ZX8-CCB. It's still in New York, and I'm in California.

I will be placing heat sick paste on the ULA before I put my system back together after the mod. But before I do, I'm going to place a sticker in the case that states the ULA number.

Joe

[Aurelbois]

You can get a Composite Video Board from a seller in Canada on Ebay: https://www.ebay.ca/itm/124844441452.
Check it out.

[DonLafferty]

Thanks! I bought one from the Canada guy because the Etsy shop is temporarily closed.

[mikeh_nz]

I've been buying it from the guy in Germany here.
I've bought two now. In in WA, USA & they take about 2 weeks to arrive in the post and I pay via paypal.
Ive found it a bit hit and miss as to how well the tv will handle the composite signal. On all of them, the image comes out nice and sharp, but some tvs have problems with keeping the image vertically stable (others are fine).

Id suggest that you buy a replacement keyboard membrane as well. I've been getting these from here (also 2-3 weeks to arrive in the mail).

Id also update the internal memory to 16KB and also suggest you install a WESPI - see the thread in this forum. It turns your zx81/timex1000 into a computer with a hard drive. You can then preload your machine with a bunch of software.