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Did anyone ever find a solution to this? I have two IIci's here with dead NuBus slots. I've recapped both of them, boards are clean without any serious damage. On one I replaced a 74ALS240 IC near the slots based on a suggestion but that made no difference. I have a pretty good understanding of...

That looks like it ought to work just fine. For this sort of application the specs are not usually terribly critical. As long as the specs are in the same ballpark it will probably work.

Ah, H11AV, I couldn't tell what the H was. Datasheet is here: http://pdf1.alldatasheet.com/datasheet-pdf/view/52725/FAIRCHILD/H11AV1.html Most of the variations you see are likely package and lead styles, temperature ranges, or the sort of packaging the parts come in. There are often slightly...

There are lots of similar opto-isolators out there. I can't make out all the numbers on that part, but a 4N35 or similar part will probably work. Do you have reason to believe that the optocoupler is bad?

C37 sounds like one of the mains filter capacitors. Guessing by the number, I would say it's probably 0.56uF 400V 85 degree C rating, but the value is not critical and the replacement you found ought to work fine. Transistors are fairly easy to test if you have a multimeter with a diode check...

It's best to replace it with the same part if you can find it and the price is not too obscene. I would expect quite a few similarly rated parts to work, but sometimes rely on specific characteristics of the original part and may not perform well with a sub. Using an exact replacement greatly...

You could just as easily say "why not just buy a modern computer?" Any modern machine would run circles around any reasonable upgrade you could do to an LC, but when collecting something for the nostalgic aspect, there's something to be said for keeping things original or upgrading using period...

Are you sure that's the right picture? What I see there is a 2SC3260 (the 2S is usually omitted from the printed number) which is listed as an 800V 3A NPN power transistor. I suspect that's the chopper transistor in the power supply. I've never seen an SCR in that package style.

I would try solvent welding. If you need filler, grind up some compatible plastic with a file and mix the filings with solvent. It will meld with the original plastic and make a very strong bond. Just don't spill any solvent, that stuff will instantly mark anywhere it drips. The stuff I have is...

There is space to put Apple II ROMs on a custom ROM SIMM at which point they are accessible by the main CPU. I have no idea how those 6502s are wired up though, they may not be usable unless they can access the system ROM and RAM. There's a lot more to an Apple II than the CPU chip.

Didn't somebody say it had a 68000 in it? If that's the case, the other parts will be boring glue logic, buffers and such and the real magic will be in the firmware.

That's why I use Ezsniper. I paste in the item number and my max bid, set and forget. The Ezsniper service puts in a bid for me in the last few seconds of the auction and either I win or I don't. I don't have to be home, I don't even have to leave my computer on. The snipe does cost something...

Sniping has always annoyed me, never made sense why ebay hasn't included a feature to extend the auction by a few minutes each time a bid comes in within the last few minutes. I figured if you can't beat em, join em though, and I've been using a sniping service for years. The way the game is...

Well, measure the draw from one, and compare it to one of the original drives, that's the easiest way to find out. Solid state option is probably the best modern replacement though, just not cheap.

If you don't want to modify the speakers, the current draw should be well within the range that one of those cheap little 50W travel transformers ought to work to power them. Just don't use one of the higher power more compact converters for hair dryers and such, those work like a light dimmer...

RS-485 is used for DMX-512. I built a clone of the Open DMX USB interface a while back and the transceiver IC is indeed just the electrical interface between a USB serial UART and the DMX bus. You should be able to use the onboard UART in just about any modern microcontroller to talk RS-485. The...

I've seen some weird interactions between materials too. A friend of mine had an old radio that was stored with the power cord wrapped around it and the rubber insulation reacted with the plastic housing somehow and they melted into each other. I had a roll of that thin yellow tape that you find...

Yeah that looks like it would be a heck of a tight fit. It could probably be done, but the thought of trying to solder all those connections makes me go cross-eyed and I'm fairly accustomed to hand soldering fine pitch SMT stuff.

Wow that takes me back. I remember printing huge banners from Print Shop on a Franklin Ace 1200 in 5th grade. I forget what specific printer it was but we had several old beasts. The Franklin Apple II clones were ancient even back then, I found a couple of them with Amdek amber screen monitors...

I like that idea, I've been using cable-end terminators for drives that need them but this is a tidy approach for space-cramped compact and pizzabox machines. YMMV but I've found that the Savvio drives seem to work fine without any additional termination. I assumed the drives have onboard...