User guide

1541 Ultimate User Manual

http://www.1541ultimate.net/

Known software/hardware issues and solutions

Keyboard problems while in menu

Some people reported unresponsive (or sluggish) keys of their C64

console while the 1541U menu was active. No problems however when in

BASIC (or normal use of the C64). I was lucky to come across a user who

experienced this phenomenon. After testing, it was concluded that the

problem was with the C64, and not with the 1541U. The 1541U worked

fine on a different C64 of the same type. Most likely cause is a defective

CIA chip.

PSU problems

The left 2 powersupplies (see picture below, number 1 and 2) do not seem

to supply enough power to operate the C64 in combination with the 1541U

in ‘Cartridge mode’.PSU 2 does have slightly better specs, and therefore

seems a bit more stable. I know Gideon uses a C64-II console with model

2 PSU. I myself am using PSU 3 on both old and new C64’s with far less

problems then other people in the field.

PSU 1

C64 (old model/BreadBin)

9V 1A

T40/E

5V 1.5A

T160mA

33VA

PSU 2

T40/E

C64 II (new model)

9V 1A 5V 1.7A 18VA

T200mA

PSU 3

T30/E

Heavy duty

9V 1A

T1.6A

5V 1.5A

T2.5A

33VA

PSU failure may be noticed in different ways. Examples:

 C64 might show a black screen

 1541U drives might not respond to commands

 Networking might fail or be unreliable

 Real drives might react strangely to IEC commands

1 2 3