The sim to pc com1 connection should work. The problem with pcmmc on the older DCS's it that it MUST be set up exactly as the manual states. 9600,8,1,none and no flow control. The software used MUST be DOS 5.0 or higher, not dos emulation from xp or vista. The software needs to match the system version exactly. There are 4 release versions of pcmmc and you may need 4.1 or ?? The software must run from the hard drive aswell
Problem is even on a good day you still may not get a "datalink". We honestly in all of the years I have been doing this do not use pcmmc for this reason. It's always faster from a keyset.
I dont know what went wrong with my pin outs. use these
sim 2---pc 3
sim 3---pc 2
sim 7---pc 5
sim 20---pc 4