davidg5678

Unfortunately, I only have a multimeter to check these lines at the moment. I'll have to double-check the CPU-GLU address lines tomorrow to confirm that everything is working correctly, but no problems were detected on my first pass today.

Yes -all of these connections are working correctly. Apart from connections going to and from the PDS socket, I tested every possible connection for both the address and data buses, and they were all good. @techknight mentioned checking control lines, but I'm not sure how to test these/where they are. (I think they have something to do with interrupts and reset, but I am still figuring out how computer architecture works in general) Believe it or not, I actually used your article from Hackaday as a guide to help with this process! I found the diagrams to be very useful, especially in conjuncti

@techknight It took me a long time to get around to it, but I just buzzed out the both the address bus and the data bus from the ROM on this motherboard. I used the matrices from the modernized schematics, which were a big help. Strangely, I did not find any breaks in either of the buses. I wasn't sure how to check the control lines, so I didn't do anything with them yet. I also checked the VRAM ICs, but all of their connections were good too. I know it has been a while, but if you or anyone else has suggestions, I'd love to hear them! I became much faster at checking c

I think so! I think it would be nice to be able to build these new boards with as many or few original parts as possible.

https://www.digikey.com/en/products/detail/molex/0766500088/2115964 I used two packages of these and some 24 gauge wire. The connectors as well as the metal pins are included. I used a pair of pliers to crush the metal tabs onto the wires. I have no idea what the correct way to do this is, but it worked fine for me. I'm sure there is an expensive professional tool to crimp these correctly, but my pliers got the job done eventually.

I made an extension cable with about $20 worth of parts from Digikey. It makes troubleshooting much more convenient as I don't have to reinstall the board between each test.

See here:

I think the lack of System 7 is probably the only reason it is not yet working. System 6 can connect to file servers on other computers just fine. What System 6 it cannot do out of the box is host its own server to be accessed by another computer. If you install System 7 on one or both of the computers, you would then be able to do either single or bi-directional file transfers with just a single cable. A fully loaded copy of System 7.5.5 might be a little overkill for these machines, but I think System 7.1 is fairly safe choice in terms of the trade-off between added features and slowdown.

I think this probably means that something is wrong with the SD card. The easiest way to find out is to try using another SD card. The monitor says that the SCSI2SD Device is ready, which probably means that it is working.

I think the CRT probably is probably already discharged at this point, as it is no longer really connected to the analog board. It is good to be cautious around CRTs because they are very delicate, but I think the main risk is probably not there at this point. Of course, it wouldn't hurt to go through the discharge procedure regardless of this. There are lots of good tutorials online that can help with this as well. As I said before, I think that there is a very good chance that the computer could still be repaired. Otherwise, there are lots of useful spare parts inside that I'm su

Would you be willing to sell the motherboard?

From what you have described, I think the CRT in this computer is (semi)-officially toast. The sizzle you heard was likely the sound of air rushing into the (no-longer) vacuum-sealed CRT. The pins look extremely bent out of shape, and I doubt that whatever event bent all of the CRT pins would not have also broken the small glass seal at the very end of the CRT tube. This computer can likely still be repaired, but you might need to find another CRT to use inside of it. It is possible this didn't happen, (the picture is blurry so there is a small chance) but from what I can make out

Normally, this guy seems to know what he is doing. I think he just doesn't have much experience with surface-mount soldering. He has done many other videos about Macs which provide some pretty good advice and show proper techniques. He has also provided CRT warnings in many of those videos too. I found the Classic Mac Repair-athon series on this channel to be quite entertaining. There are definitely better ways to solder down SMD chips than the way he did things in the video though. Everything worked out well in the end at least.

I love this idea! I wonder if these are small enough to fit powerbooks too? Either way, I think cheaper SCSI emulators for old Macs are a good thing. It always hurts me a little to buy a product that costs more than the computer itself did, and I think as long as performance is on part with spinning metal, it's okay. Count me in for PCB interest.

I'm glad I'm not the only one to spot the resemblance between the mouse and Cybertruck. In fact, I made this photo shortly after the Cybertruck was announced.