Hardware Change To Make 1541 Device 9

[Dr-D]

Here is an image of my Commodore 1541 floppy drive board. How do I permanently change this to device 9?

Thanks.

[orion70]

From the Service Manual:

Code: Select all

DEVICE NUMBER CHANGE 
The 1540 and 1541 drives are shipped from the factory se for device # 8. The channel can be 
hardware altered to # 9, 10, or 11 by two methods:  
1) Refer to appropriate board layout drawing for the location of the pads provided for this purpose. 
The device change pads must be CUT to alter the channel number and re-soldered if another change 
is needed later.  
2) The preferred method to alter the device number is to lift certain pins of the 6522 chip. The I.C. 
should always be socketed, so removal of the chip is simple. Once removed, the proper pin can be 
carefully bent to eliminate it from the circuit. If another change is needed, simply remove the I.C. and 
re-install with the pin back in place.  

PCB ASSY #                     LOCATION              DEVICE #          LIFT PIN 

1540008                         UAB1                     9                15 

1540048 
251748                          UC3                     10                16 

251834                          UC3                     11             15 and 16 

Hope this helps.

[srowe]

The pads you need to cut are on the very right of your photo near to R35.

[Dr-D]

I've zoomed in on that area and posted another pic before I cut anything as I still don't know what to cut. My PCB # is 251777 The ASSY # is 250442.

[Dr-D]

I got it figured out. When I think jumpers I think of protruding pins rather than flat little semi-circles of solder. I've got it set to device 9 now. Thanks for the help in getting me zeroed in on the right area.