behines
Member
Hello,
This thread is the first in a series of questions about upgrading a Model III from diskless. I am new to Model III so am looking for advice and "gotcha" tips.
I am upgrading a diskless Model III to include a floppy and hard disk.
I have a bunch of stuff I'd love to get input on, but I have two main question I'd love to get input on. The first is
1) Power connector for the floppy controller (and for the RS232 card)
I purchased both a original floppy controller and RS232 card. What's baffling is that the power connector seems reversed from what's on the motherboard. Here's a photo of my motherboard's power connector at left and the floppy connector at right:
As baffling as it seems, I did a deep dive into the schematics and circuit board layouts in the Tech Ref, and in both cases we have +5V on pin 1 and GND on pin 2, etc.
I may have made sense of it when I discovered this photo on Dave's Old Computers site of a Model IV, showing the floppy power connectors indeed wired "backwards", with red on the right:
I have made my own power connectors (as part of a "franken-cable") with my new power supply that uses this Jameco part and pins, that have red on the right:
I believe this to be 1) correct, and 2) proper form, in spite of the fact that it's the opposite of the motherboard power connector. Is this all true?
This thread is the first in a series of questions about upgrading a Model III from diskless. I am new to Model III so am looking for advice and "gotcha" tips.
I am upgrading a diskless Model III to include a floppy and hard disk.
I have a bunch of stuff I'd love to get input on, but I have two main question I'd love to get input on. The first is
1) Power connector for the floppy controller (and for the RS232 card)
I purchased both a original floppy controller and RS232 card. What's baffling is that the power connector seems reversed from what's on the motherboard. Here's a photo of my motherboard's power connector at left and the floppy connector at right:
As baffling as it seems, I did a deep dive into the schematics and circuit board layouts in the Tech Ref, and in both cases we have +5V on pin 1 and GND on pin 2, etc.
I may have made sense of it when I discovered this photo on Dave's Old Computers site of a Model IV, showing the floppy power connectors indeed wired "backwards", with red on the right:
I have made my own power connectors (as part of a "franken-cable") with my new power supply that uses this Jameco part and pins, that have red on the right:
I believe this to be 1) correct, and 2) proper form, in spite of the fact that it's the opposite of the motherboard power connector. Is this all true?