Sinclair ZX80 / ZX81 / Z88 Forums

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 ...

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, c...

That looks most excellent! :D 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 load...

Saw these 3 wonders on display at the museum (Teknisk Samling) on the insle Bornholm in Denmark today.

1024mak

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

PS Driving to the southern part of Jutland from Sealand would be economical suicide with present fuel prices.....;o) PPS A fine little LM358 OpAmp mono music amplifier is ordered. (ref to: MOGGYS post in this tread from: Fri Sep 09, 2022 11:34 am ) Have a nice weekend! If I read your post correctly...

Maybe we should find out if the signal reaches the CPU. How about 2 oscilloscope pins connected to D7 (tape in data) and /IORQ (I/O access). Then we can see tape data when /IORQ is low. I don't know how many port reads/writes happens during tape read, but tape data read would be the most frequent. ...

Maybe we should find out if the signal reaches the CPU. How about 2 oscilloscope pins connected to D7 (tape in data) and /IORQ (I/O access). Then we can see tape data when /IORQ is low. I don't know how many port reads/writes happens during tape read, but tape data read would be the most frequent. ...

mrtinb wrote: ↑Fri Sep 09, 2022 1:29 pm And Jesper, where do you live? Maybe we could meet to test with working hardware.

That would be fine - to identify non working components.
If geographic distance is acceptable of course. I live near Roskilde.

Hi Moggy Thx for replying. I am using a LM358 OpAmp, and the breadboard circuit is not identical with the drawn schematic. I will post the build circuit schematic later. I could try building a better amplifier, but when looking at the result (output) from the present amplifier - i gain the result i ...