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    • My experience was that on drives that did not have any option for narrow mode terminating the upper bits would often get the drive recognised however even with correct termination some drives just wouldn't work on a narrow bus, and some would work on newer macs but not older ones (I have a 18GB drive in my PM 8600 that works fine in the PM but doesn't work on any 68K I have tried it on). I actually had quite good success with using U320/U160 SCA80 drives in 68K's but I did try and keep to the smaller, older drives. If you are ever looking to purchase SCA80 Drives to use in 68K's the 2.5" segate drives used in the IBM eServer's (i'm not sure of the Seagate P/N offhand) tend to work pretty well, I have a box of 15 or so of the 72GB versions that I am slowly working my way through as my 68k's need new drives and I am yet to find anything they don't work in.   One note about the way I terminated the adapters, the method I used really requires a 2.85v regulator, these (at least in the UK) are pretty hard to find and I ended up ordering the parts from china. You can make do with 2 or 3 diodes off the 5v / termpower lines or a 3.3v regulator but it's not in spec so could cause issues (it never did for me but as @trag points our in the thread it's not the correct way to do it)   On a side note - I do still have quite a few PCB's and parts for the terminated adapters I used to make so if anyone is looking for a terminated adapter feel free to drop me a PM, I stopped making them as I didn't think there was any demand for them after SCSI2SD came out
    • IT LIVES   After months of hibernation, an elusive Quadra 950 emerges from its sleep.     But there's still a small problem... Since most modern ATX PSUs regulate themselves based on what they see on the 12V rail, it is important to get it right. - Without the load resistors, the 12V rail was too high (12.5V). The PSU was clearly having issues with that rail and the ATX fan was on at full blast. - With some load resistors (2x 24Ohm 7W), the 12V rail sits at 12.25V (much better) and the fan is running at the lowest RPM setting BUT some smoke was coming out of the resistors… Not good!   Turns out that was caused by a miscalculation on my part. It’s only by doing mistakes that you learn! Basically, I wanted to use two resistors in parallel and forgot to adjust the resistance.   Explaination: The current draw depends on the resistance. A 24 Ohm resistor placed on the 12V rail will consume 0.5A (that’s what I aimed for as it’s the minimum load for the 12V rail according to the Bicker’s spec sheet). Power-wise this equals to 6W of dissipated heat. I chose a 7W (max capacity before blowing up or rating) resistor but the safety factor was too close to 1 (hence the smoking). Furthermore, I placed two side by side, thus drawing 12W or 1A. So I was drawing too much and the safety factor was too low.   What I should have done: Since the resistors are in parallel, in order to draw the same power as one single resistor, you need to "double" the resistance rating (make the value larger ie decreasing the overall resistance of the resistor). So instead of 24 Ohm resistors, I went with some 47 Ohms. Each resistor will draw 0.25A (or thereabouts), two resistors (in parallel, which can be considered as two independent loads) will therefore draw about 0.5A. 250mA on a 12V rail corresponds to 3W (per resistor). So a 10W package should be able to dissipate that heat without too many issues.   The display has arrived but I can’t do anything until I get the new resistors. I should get them in a couple of days. So testing will have to be delayed until next week.
    • In my experience, this is exactly what I did: plug the v.5.5 directly in the Mac and Apple IIGS scsi plug.
      Only with Quadra 700, due to the case angles on the back, I couldn't manage to do it without taking the case away, or using a scsi zip drive cable.
    • Capacitance between A and B?  Current flows to charge the cap(s) just long enough to trip the buzzer then stops
    • Hey guys, I just finished recapping my logic board in my Macintosh portable M5126. When I try to power it on with a fresh, charged battery, It does nothing. This is exactly what it did prior to cleaning the board and replacing every single cap. 
        I’m new to this stuff. The battery terminals in the computer are reading 6.4 volts. I’m not sure where to go from here. Any assistance/input is greatly appreciated.   Thanks, Gary.