Sinclair ZX80 / ZX81 / Z88 Forums

1024mak

Thanks for your input - when getting som gates, i will return the result.

Moggy wrote: ↑Fri Sep 16, 2022 2:40 pm That looks most excellent!

One thing for sure is that if this does not cure the problem then it can be eliminated and the fault lies elsewhere.

So, some weeks ago i received the LM386 amplifier.
Turned the signal level from the MaxDuino up from 4,2V to 5,0V, unfortunately without any succes loading any programs into the Lambda.
Så for now the "signallevel to low error " will be put on standby.

Next step is to filter out (with OR gates 74LS32) the EAR signal into the CPU, to see if any signal at all enter the CPU.

What a journey. We’re cheering you on.

jesperp wrote: ↑Sun Sep 18, 2022 4:34 pm 1024mak

Thanks for your input - when getting som gates, i will return the result.

So, the 74LS32 fitted on a breadboard - a little breakout board in the back of the Lambda.
Pictures and scope pictures will tell the story.
I am sure 1024mak is able to decode the results. The output from the gates, changes when data is streamed into the EAR input.

Do not give up jesper.

As Martin says we are cheering you on to have success with this project.

mrtinb wrote: ↑Mon Aug 29, 2022 4:21 pm Hi Jesper.

I've been thinking about making a video for you, for quite some time, to show how it looks to me, when I load a game on the Lambda 8300.

I hope you can compare the picture and voltages with what you have.

https://youtu.be/riutTeCjOLM

Back again

I have just re-viewed the video Martin did some time ago.

In my setup i am using a LCD monitor wich is showing a fine picture (via the MONITOR output), as long as the Lambda is not loading (LOAD"") from the EAR input. When loading, my LCD monitor is going into a blue screen (waiting for a signal).
Because i am not able to monitor the flickering screen in LOAD-mode, i have no chance comparing my screen stribes/pattern to Martins screen pattern in his video.
Next step, must be to try my setup with another monitor/TV (CRT), connected to the Lamda's antenna output.
I believe this will reveal any signal problems - as for now, my Lamda never ends with the "OK" after a finished LOAD session.
Will find mee a fine small TV set in a second hand shop in the near future....

jesperp wrote: ↑Fri Nov 04, 2022 4:25 pm Next step, must be to try my setup with another monitor/TV (CRT), connected to the Lamda's antenna output.
:
Will find mee a fine small TV set in a second hand shop in the near future....)

Good luck finding an old TV my friend.

I’ll have a look at the attachment and photos in the earlier posts tomorrow.

Mark

Okay, real life is getting in the way, I’ve not forgotten.

Mark