Recent content by tony359

and no, I tried the contraption on the board where the 447 ADB works and it's the same behaviour. That board also features the original VIA so that is not the issue either and the clock is the same on both boards. I'm stuck :)

The VIA - I currently have installed the WDC replacement, not the original one. But I am not aware of any issues with that replacement. One thing I'll check is the clock stability: it was a bit jittery but that's usually because of my long ground lead, for convenience. Right now the flipflop is...

Thanks, I appreciate the help. I don't think I've got the skills to go so deep into the problem - it puzzles me that with the external clock nothing works altogether though. I tested the very same PIC with the "447 code" and it works as before (the mouse freezes every second or so) so the PIC is...

hi @Tashtari I've only now found a minute to test. It doesn't work, it gets stuck at RAM test. I checked the clocks, I have 3.6MHz from the board, into the flip flop and then I see 1.8MHz into pin 16 of the PIC. Is that expected? I thought the FlipFlop would divide by 4 and I would get 500KHz...

Yes I understand, I think you mentioned to the guy who came up with the mod before. This mod might give you another data point to confirm it’s a clock issue if it sorts out the issue in my case too. For now, I have ordered a 74F74 :)

Yes, the very same PIC16F88 works on one board but on the other the mouse stutters. The mouse is a genuine Apple. If I put the original code (on an 87 I had handy), at least the first board crashes during boot with address error as previously observed. Sure, I'll test the PIC16F88 on the...

I just tried and... it WORKS!!! I put the old back in and got the error message straight away. Amazing, thanks a lot! Wait: no, on my other SE board, it boots but the mouse stutters, as if the ball was dirty. If I install the genuine ADB chip, it works perfectly. Well I guess we've managed to...

It's taken me a while @Tashtari but I am taking a look now. This is what I see when I read the PIC - I can see the values you mention on the bottom right, does that make any sense to you? This is the "config" tab.

Ah wait, the configuration registers. Yes I think they’re on a separate tab. Let me check that again. Thank you!

Silly question, @Tashtari, how does 0x2007 translates in what I see on the attached - or what Notepad++ in Hex mode displays?

Hi @Tashtari Finally my PIC16F88 have arrived (after a seller sent me an empty bag because they wanted more money than advertised!). Still the same issue. The Mac boots but crashes almost immediately with an address error. The mouse either doesn't work or is not smooth - that is, it jumps...

I've got some other PICs arriving, the 88 this time and not the 87. I'll test and report back!

I'm joining this conversation again to ask for an opinion. Some time ago I made my own PIC using tashtari's code - my Mac SE started working again and happy days. But over time that Macintosh was always unstable. Intermittently. A few days ago I decided to play with the techstep I borrowed...

Hi. A bit late to the party here! I think the Mac Plus I recapped has the same -13ish line. I don't think that line is critical and it's usually a bit off. The voltage adjustment though MUST adjust the positive rails! I'm not sure that that is your problem with the sound but there is definitely...

And this is the video of the repair! Comments and feedback are very welcome as usual! The inductor seems to be ok! I have a Colour Classic on the bench now, that's not as easy...