Which 1541 is this?

[Justin Payne]

So, I picked up another C64 and drive the other. The bad news is both didn't work. The "good" news is after closer inspection I found out that my old drive, that also doesn't work, has a 1540 label on the bottom and a 1541 case label on the top. Both are that same beige color so that wasn't something I would have expected.

OK, so back to the 1541. It has a board that says revision A. The chips were manufactured in '84 and it's missing UC7. Here is a pic.

http://1drv.ms/1JiHtWL

 

I'm trying to repair the thing but the troubleshoot instructions don't cover one w/o the UC7. I did find some w/o UC7 but they also had resistors where UC7 should be. Mine, as you can see, has the place for resistors but no resistors.

 

Which version am I looking at?

 

[+OLD CS1]

Given the 251968-01 ROM and the 251854 marking, it appears to be a 1541C board. Though I used to have one I have never looked at the bottom of a 1541C nor do I have one in my "collection" anymore, so I cannot speak for the validity of the bottom label, but it seems that 1540 bottom should be from the old VIC 1540 model drive. I used to have a VIC system with the 1540, but I cannot recall if it was the same color as the 1541C.

 

According to Zimmers:

 

 

This drive was introduced around the same time with the C128 and the 1570, to make it look like the C128 and the 1570, which was also in a white 1541-style case. The C128 was also white. This drive has an optical track 1 sensor, but it won't be used unless the jumper J3 on the board is cut.

[Justin Payne]

Great. Well, that helps a lot. Thank you.

[RobertB]

Have you asked Ray Carlsen for clarification on the drive you have? He's right there in Ethel, Washington.

 

Truly,

Robert Bernardo

Fresno Commodore User Group

http://www.dickestel.com/fcug.htm

July 18-19 Commodore Vegas Expo v11 2015 -

http://www.portcommodore.com/commvex

[Justin Payne]

No, I hadn't but I will. Thanks for the tip.

We're having a bunch of people bring their C64's to the Seattle Retro-Computing Society this month. There are some pretty smart guys that attend but I thought I would give it a shot first.