My Klyball 600D build

[HOWARDHB]

Well done!

That IS a good result.

Posting all of your efforts here is surely going to assist me

H.

[ronin47]

Well done!

That IS a good result.

Posting all of your efforts here is surely going to assist me

H.

Well just shout if you have any questions and I'll try to help.

I have to say that the folks here are fabulous and super helpful and I'm grateful for all the help they've given me.

[jbtech]

Finally this is the output of the op amp on the tape in side:

IMG20240610160420.jpg

This looks OK but I now need to trace it through to pin 2n on the 6850, see what that looks like.
And again this looks ok, though mildly shifted to the right again. I believe we have 1200hz for logic 0 and 2400Hz for logic 1 here too.

Hi ronin47, I just wanted to double check if that image in your previous post was the output (pin 6) of the CA3130 op amp in position U66 or the input (pin 2)?

If that trace was from the output then there is a problem in that stage as the op amp is configured as a comparator - a small signal on its input pin 2 (which is limited by D9 and D10 to no more than +/- 0.6V) should cause the output pin 6 to toggle between 0V and +5V.

Here's a photo of the output pin 6 of U66 on my board taken while loading a program, at 5V per division. The signal should look like a 'square' wave with amplitude of 5V, even with a very low input signal Voltage.

- just checking in case there is an issue with that component on your PCB which could explain a poor input sensitivity and data errors.

Hope that helps, regards John.

IMG_2566.JPG (2.81 MiB) Viewed 14992 times

[ronin47]

Finally this is the output of the op amp on the tape in side:

IMG20240610160420.jpg

This looks OK but I now need to trace it through to pin 2n on the 6850, see what that looks like.
And again this looks ok, though mildly shifted to the right again. I believe we have 1200hz for logic 0 and 2400Hz for logic 1 here too.

Hi ronin47, I just wanted to double check if that image in your previous post was the output (pin 6) of the CA3130 op amp in position U66 or the input (pin 2)?

If that trace was from the output then there is a problem in that stage as the op amp is configured as a comparator - a small signal on its input pin 2 (which is limited by D9 and D10 to no more than +/- 0.6V) should cause the output pin 6 to toggle between 0V and +5V.

Here's a photo of the output pin 6 of U66 on my board taken while loading a program, at 5V per division. The signal should look like a 'square' wave with amplitude of 5V, even with a very low input signal Voltage.

- just checking in case there is an issue with that component on your PCB which could explain a poor input sensitivity and data errors.

Hope that helps, regards John.

IMG_2566.JPG

It's a little difficult to tell from your scope image, however the pin 6 I was talking about was on the 6850 and the pin 2 was also the 6850.

Its a bit confusing because the op amp also uses pins 6 and 2.

The input of the op amp is really very small, but pin 6, the output of the op amp is 5v and by the time it gets back to the 6850 it is a square wave. What you see is a 150Hz square wave generated by a program @bxdanny gave to me that I traced from the 6850 out through the aux pin (9) and all the way back in again via pin 10 and all the way through the op amp and logic ICs to the 6850.

[bxdanny]

ronin47,

Now that you have the tape interface working, how about giving that Monster Maze game another try?

Controls:
Q = up
A = down
0 = left
: = right
R = restart (when game is over)

[ronin47]

ronin47,

Now that you have the tape interface working, how about giving that Monster Maze game another try?

Controls:
Q = up
A = down
0 = left
: = right
R = restart (when game is over)

I will, but been into the office today so no option to try.

[Reggraham]

Hi
I have read through this, I'll keep my eyes open for a second hand B&W display, one question I have is where did you get the keycap set? I have had to use stick on labels so far and still have some blanks, the little vero board by the video out is the buffer and the other is a shift lock mod so I can use a normal key switch with a couple of track cuts.

IMG_5979.jpg (3.4 MiB) Viewed 10875 times

[Reggraham]

An update to my sync problems is it is different depending on the monitor ROM fitted.
With CEGMON SBII version it never syncs on startup and I always have to press reset the D/C/W/M prompt is outside visible display and I have to enter values so I can the adjust the sync.
With SJGMON BETA-011 it's a lot better most of the time it starts ok with the prompt and syncs about 50% of the time on startup
With SYN600 it starts nearly every time and syncs but the keyboard mapping is weird, shift lock has to be on to enter to the C/W/M or use left shift key, right shift key gives completely different characters.
With shift lock off, no shift A key gives a, left shift A, right shift Q. No shift 1 key gives Q, left shit 1, right shift !
Caps lock a key gives A with either shift key gives Q, 1 key gives 1 with either shift key gives !. return only works with either caps lock or left shift
I think the SYN600 I used was mapped for a C1 but I thought they were the same?