Recent content by bigmessowires

You also may need to add a small bias resistor to VCC or GND in order to tell the difference between a true high/low output signal and a signal that's merely floating. For example after you desolder the two resistors, add a 10K resistor between the VGC output and GND. If the signal is still...

How are you testing? Are you watching the signal with a scope while you reboot the computer? Are there any disk drives connected to the system?

Maybe something else is shorted to one of those signals and is forcing it high? I don't remember if the IIgs has some kind of RC filter mechanism on those I/O signals, but those have been known to fail in compact Mac disk signals.

Unfortunately I don't have anything to add beyond what I wrote here in 2021. I would strongly suspect you have a hardware problem somewhere, but your test results are puzzling. The TLDNR of it all is that the IIgs must be capable of driving a logical 0 (close to 0 volts) on both HDSEL and...

The startup sound in the ROM-inator II isn't a single digitized sound sample that you can easily replace. It uses the Sound Manager to create a chord by layering multiple simple tones with different frequencies at the same time. It's been a while, but I think the data for a single tone is the...

Thanks, I spent a good while considering this during design, but finally decided it really isn't an issue. I used it extensively with both horizontal and vertical video ports. But you could use a short DB15 to DB15 cable as an extension if you're concerned. Maybe something like...

I missed the beginning - you were successful getting the Classic ROM working? Wow! I'm not really looking to make any more ROM adapters for compact Macs, but if somebody else wants to try it, the design of the ROM-inator I (for Mac Plus) is available on the BMOW site and it might not take much...

It's been a long time coming, but the Mac Sync-inator is officially launching today! See the announcement for more info. Thanks for everybody's suggestions and feedback through the long development process. If you've ever struggled with getting a VGA monitor to work with your classic Mac or...

This is my recommended method for cleaning the LCD used on the Floppy Emu A and B: As others have said, you can also find a replacement "Nokia 5110" LCD on eBay, AliExpress, etc. There are a few different pin arrangements used, so be sure to get a replacement that uses the same arrangement as...

Yeah, there isn't a lot of extra space when plugging in to some of my slotted Macs either. I'm not sure what can be done about that, though. A DB-15 connector is a particular size, and a PCB that's mounted under a right-angle DB-15 is a particular thickness (to within a few tenths of a...

Nice! Yes that's normal that some Sync-inator sync modes won't work with some computer-to-monitor pairs. It will depend on the behavior of both the computer (or video card) and the monitor. That's an interesting half-image you got in the first photo, though! Did you try running the monitor's...

Interesting! But I fail to understand what the risk of hardware damage is. They make it sound like after connecting an HD20 but prior to installing the extension, you would have some bus fighting or short circuit on the disk I/O signals. As far as I'm aware there is no risk. If there were a...

Awesome data, thank you! When this happens it means the computer isn't outputting any video data. It's dead, Jim. I've updated the troubleshooting section of the product page to clarify: https://www.bigmessowires.com/mac-sync-inator/ I'm not sure why those Pivot SE/30 cards aren't outputting...

This is now fixed, but existing beta testers may still run into this problem. It turned out that the 6200 (and probably other PowerMacs) has a composite sync signal structure that's different from any of the other examples I'd looked at previously. It doesn't really matter since you'd normally...

Thanks, I'm going to wait for results from the three beta testers I have now and then see how it looks. You shouldn't expect the Sync-inator to affect washed-out colors, though. It transforms the composite sync, horizontal sync, and/or vertical sync, but doesn't touch the analog RGB signals at...