Either way, a lot of people eat it because it is, well, fast!
Back in those days, I was an installation team leader in the IMB/NatWest 'RBP Project'. We installed what was then the upgrade to all the Nat West banks in the UK (RBP - Retail Banking Platform).
There could be quite a few engineers on site as we used to try to get one bank done in a day. But come lunch time, who is going to grab the McDonalds orders? I drew the short straw on more than one occasion and decided to do something about it, as I had a Series 3 in my 'bum bag' and so I decided to knock this out one lunch time. Actually, it was modified over about a week as new things were discovered as missing - totally organic and unplanned software! It worked! Enjoy!
But how do we run this?
There are a ton of emulators and other really useful software and information here;
I have found the later PsiWin software to be somewhat 'slicker' than the earlier version, but to not have so many useful features. I personally use PsiWin v1.1, because it converts well and provides the Psion Database Manager, which 2.3.3 does not. Your choice!
As for cables, then you'll need the "soap-on-rope" Comms Link for the 3 and 3a machines. These had both DB25F and DB9F RS232 connectors. The later ones had a slimline multiway connector on one end of the cable and a DB9F RS232 on the other. The HC & Workabouts can use a DB9F to DB9F 'null modem' cable.