You should follow these instructions if you already have an XM1541
multitask cable and you want to transform it.
- Because you will solder a cable onto some pins of the VIA#1 chip
inside the drive, you will have to first make sure that these pins are
not used for any other purpose. This depends on the version of the
drive you have:
- In original Commodore 1541 drives, nothing is defined to any of
the bits of Port A. You can solder the cable without any problem.
- In 1541C drives, bit 0 of Port A is used for the detection of
the head being over track 1. After stripping this connection off
of the chip, you will have to replace the DOS ROM with that of the
1541 or the 1541-II. Otherwise you'll get strange results when the
drive is seeking: the DOS tries to rely on the detector line which
doesn't exist anymore.
- In 1541-II drives, bit 0 of Port A is grounded, strip this
connection off of the chip.
First, create the parallel port for 1541 drives
or the parallel port for 1570 and 1571 drives.
You need the following parts to build this cable:
Step 1. Solder one end of the cable onto the game
- One solderable 15-pin male plug (PC game plug)
- A shielded or unshielded 8-wire cable of, preferably at most, 2
Step 2. Solder the other end of the cable onto the parallel
plug. You should have the following connections:
|| 2, Data 0
|| 3, Data 1
|| 4, Data 2
|| 5, Data 3
|| 6, Data 4
|| 7, Data 5
|| 8, Data 6
|| 9, Data 7
| not connected
|| 18-25, GND
The original connections of the XM1541 multitask
cable are shown in grey. You can find the description of all parts
used on the diagrams at the legend page.
Source: The Joe Forster-STA