guus.assmann wrote: ↑Sun Sep 24, 2017 8:20 pm Data-General Nova and Eclypse.

Was that any less painful than described in The Soul of a New Machine by Tracy Kidder?

exxos wrote: ↑Fri Oct 06, 2017 9:21 pm Can you send me a couple of those 1377 chips to try in my test machine here ?

Sure, but somewhere next week, everything is packed now.

Hello, All the way back to the beginning? Is there a 4.433Mhz crystal on the board? The reason for this question is, that this crystal is the supply for the signal you're looking for. And of course it's only needed for a PAL machine. ;) I.m.h.o, the CCLK stands for "Color Clock" If this s...

Received one more 1377 39th week of year 90 and everything is the same with this one as well (w /o pin 9 connected).

So I guess 5 1377 can't be dead on arrival.

Once you've got time, could you also please show your pin 1: and pin 2:

I thought that too and have even bought more MC1377s, but if I just measure pin 9 on socket without the IC, then I should see something like >5-6VDC, but I see only this: I would confirm your IC's are "blown" on your other machine before anything else.. or try a brand new IC (never before...

Hold up.. SDS00008.jpg If that is 6.7V there, then the IC is getting a external DC bias somewhere. Like Q404 C-B short.. feeding 12V into 1377 pin 9... I think you need to try one of the IC's like you are using now in your working ST and see if you have composite there.. I have a feeling now that e...

Number_Nine wrote: ↑Sun Oct 01, 2017 10:53 pm

Number_Nine wrote: ↑Sun Oct 01, 2017 10:50 pm It looks a bit like an audio signal, maybe it's trying to say something:
SDS00009.jpg

Jokes aside, with the same time frame as your picture:
SDS00011.jpg

Same with pin 9 upwards:

Yeah, so you see composite PAL signal (with colours from pins 3,4,5 added onto composite sync after colour burst), and on pin 2 you'll see only composite sync of the same form, but without colours. On my machine I see this on pin 2 (correct form): SDS00007.jpg But only this on pin 9: SDS00008.jpg I...

It's not great no. Though the scope will be loading the signal and causing some issues anyway. So I think your input to pin 17 is just fine by the looks for it. .. As for pin 9, I see this... again with 100mV/DIV X10 probe. c4.png Yeah, so you see composite PAL signal (with colours from pins 3,4,5 ...

I see it, but it's very unstable and jerky. Is it fairly stable on your machine? It's not great no. Though the scope will be loading the signal and causing some issues anyway. So I think your input to pin 17 is just fine by the looks for it. .. As for pin 9, I see this... again with 100mV/DIV X10 p...