New member from Oregon, USA

[desiv]

Nice!!!
I found an UNO shield that had come with a kit I got a few years ago and decided to use that.
Here's my progress..
TZXduino WIP by Desi Villaescusa, on Flickr
I haven't wired in the buttons, so they are there, but not doing anything yet...
And I have to add the wire for the audio (I'm going to try a wire w/ plug rather than a socket to keep it all small).
And I will solder some wires in for the LCD rather than having them use the pins like they are now.

But I wanted to test the uSD card I had just hooked up. (It is plugged into a header I added to the shield.)

I don't think I'll do a full case, but will probably Tinkercad something up to hold the LDC to the UNO/shield.
The one thing that bugs me is that it shows that stupid Windows "System Volume" directory. And apparently there isn't a simple way to remove it without MS putting it back. Thanx for helping MS!!! ;-(
I might look into the TZXDuino 1.18 code to see if I can skip that in the code. Or have it display some alternate text and not allow clicking INTO that directory...

[desiv]

I've made some progress on my TZXDuino, getting it all wired up except for the mono cable, which I am waiting for....

I was having some issues with my Timex Sinclair 2040 (Alphacom 32) printer.
I plugged it in, but nothing was happening... Checked my PSU, and it looked good... Right AC voltage...
But couldn't get it to do anything....

I opened the printer up, and it looked OK at first glance...
So I plug it in and start checking it... Maybe the power connection isn't great...
So I am holding in the ON/Advance button and I start playing with the power cord where it plugs in... A bit awkward, but then...
It advances.. and then stops...
Hmmm keep poking around... And sometimes I can get it to advance, and other times not..
I am thinking it is the power connection (maybe a cold solder joint?) or the plug doesn't actually fit as well as I think.
But every time I think I might have figured out the location of the problem, I keep playing and... Nope....

Hmmm..

Then it hits me...
Could it be the ON/Advance button and not the power at all?
So I start checking there and...

Yep...
Not the power, it's the button!!!! Aarrggghh!!!

Start working the button, adding some contact cleaner and activating it....

And now....
It's pretty darn good!!!
Even got my 8's and 1's self test!!!!
And for the true test...
LLIST
And it works!
(Yeah, I know, not as much fun just using a 40 column thermal printer nowadays compared to some good ZX81 games, but still...)

[mrtinb]

Great to hear. The Alphacom 32 is great hardware, just works year after year. I have one though where an IC is broken or something. I haven’t found the error, as it was cheaper and easier to find a replacement unit online.

[desiv]

OK, got my short mono audio cables so I "finished" (in quotes for a reason) my TZXDiuino.
TZXduino done by Desi Villaescusa, on Flickr

Yeah, no case, but the screen is actually attached fairly well with two zip ties, so.... I might keep it like that (for a while at least).
I can power it with USB or a barrel connector. I have a 9V battery plug that came with this Arduino kit, so I can run this off of a 9V battery too.

And as for the printer:
Timex Sinclair 2040 by Desi Villaescusa, on Flickr

desvi

[desiv]

Just a bit of an update of where I am with this...
It's been a while since I've had a chance to play/work on my TS1000, but just ordered a few things, so hoping to do a bit more.
What I have working on my TS1000 is the new keyboard, did the 16K internal mod, and the ZX8-CCB for composite.
When I did the composite work, I also changed the channel switch to a 50hz/60hz switch.
Also I built that TZXDiuno and it works great still...

What I still have to do:

My Composite jack is broken. It works, but the part that sticks out on the inside of the modulator to contact the center post of the plug had snapped off. It works when held in place with the plug, but the jack needs to be fixed/replaced.
I did order another composite jack, but not sure how simple or hard it will be to get the broken one out of the old modulator case... Since I'm not using the modulator (it's been gutted and I have the ZX8-CCB in there), I could just remove it and replace it with some type of box that holds the RCA jack if I can't get that broken jack out of the old modulator case... We'll see when I get a chance to look in there...

I still have the old voltage regulator in there. I did just order a couple of Tracos to replace it (I also have a USA model ZX81 I haven't touched yet.)

Lastly, there are the jacks for power and Mic/Ear. At least on the ZX81, I know that Jack is problematic.
So I ordered some replacements that should work. I think the others might be OK, but I ordered 4 of those jacks, in case I need to replace more...

Now I just need to (when the parts arrive) get some time to work on them.

I also will possibly 16K mod the ZX81 and I'm sure it will need a new keyboard too... Probably another composite mod board of some type...
(Unless I decide to not modify the ZX81 at all, which I am considering... That would still probably be replacing the power jack, as that is known bad.)
The thing about replacing the keyboards on these is that the USA models are slightly different.
Yes, I actually got the adhesive USA keyboard overlay for my TS1000, but I haven't applied it. Since I use it, I'm not as worried about it being "authentic." But the ZX81, I haven't decided...
And I just know that if I open it to get at the board to try to replace that power jack, the keyboard membrane will crumble...
So I might not have a choice there... I plan on having all the needed pieces on hand and will decide whether to update it later.
I also have a 16k RAM pack that didn't work the one time I tested. Whether that was because it was bad or just dirty connections, not sure...
That's a possible project for another day.

[mrtinb]

Nice read.

Thank you for your update.

[desiv]

OK, got the parts a bit ago, and finally got the time to work on my TS1000...

The first issue was the RCA jack for video...
The metal tab for the center pin inside the jack had snapped off. It was pressed back in there (it was like that when I got it; I didn't notice till I did the composite mod) and while that worked, that wasn't ideal.
So I ordered a replacement jack, but I wasn't sure if/how I would get the broken one out...
Took it apart and started looking...
I could get it to spin, but I couldn't pull it out or press it back thru...
I was guessing at this point that it was some type of press fit?
So I decided that the way I could get it out was to compress it and then push it back inside and out.
Luckily, it was pretty soft metal. So I got the insides (what was left of the center jack and whatever that insulation material was) out using a screwdriver and pliers...
Then I used the pliers to squeeze it at different places to weaken it and create some splits in the jack. Then I would take the pliers and fold a piece back and forth to snap it off. When I had removed a couple of pieces and the was some room to squish it, I did that, and it worked and I was able to push it back thru and take it out from inside the modulator case. Nice...
Then I took the new jack (it was one of the ones with threads and a nut to hold it in place) and put it in the same spot. A bit smaller, but not so much it pushed all the way thru, and with the lock and ground washers, it looked to have plenty to hold it in.
So after fiddling and getting the nut screwed on and getting it pretty tight, I soldered center wire in (my ground wire is soldered to the modulator case) and tested it and it works great! And I think it looks pretty good.

(Is this image link going to work? I'm never sure with these things... If not, it's just a picture of the side with the new jack. Ah, Got it! )
Tested it and there is a picture! Didn't ruin anything!!!

And, since I had it open, figured it was time to replace the voltage regulator with the Traco I bought.
Removing that pin that was on the ground plane wasn't easy. It's a bit tight, but got them all out and then added the Traco.

Looked good, so tested it again, and there's the K!! Woo Hoo!!

Ok, put this think back together, and since I have tested, I just screw it all back together and check it out and...
er... some keys aren't working... <sigh> I didn't test that...
Take it apart, remove and replug in the membrane (it's a fairly new membrane). Test it (without the case fully back together) and...
NOW it works.... I just didn't have the membrane plugged in right.

Put it back together and it's looking good.
Have 3D Monster Maze running on it now.
I still have my USA model ZX81 to look at, but that will be for a later time....
Mostly useless mini update: I finally got some decent double sided tape and reattached the feet. Yeah, I know, silly update..

[1024MAK]

Yes, sometimes you think the membrane tail is fully home in the socket, but…

Thanks for the update

Mark

[desiv]

Question:
What are some of your thoughts on adding heatsinks to any of the cips?
ULA? Other?
Required?

I have replaced the Voltage reg with a Traco already, so that should keep the heat down a bit.

But, next time I open it, should I add a heatsink to the ULA or ? Worth it? (Will the case close?)
I have a pack of little ones that came with some Raspberry Pi stuff around here somewhere...

Just wondering?

[mrtinb]

This topic has been discussed before on this forum, and there are heavy opinions on both sides. Please don't start the heated discussion again. You can search the forum for opinions in the debate.