slow script

Hi all. I am developing a system using php 4.3.2 + apache 1.3.29. The db is a mssql msde (we’re going to mysql, but not yet due to some internal reasons). All things are running in a local, standalone station, because we had to use the app on line and off line states. The off-line one should have all stuff, so. It just connect to internet to send a data replication. The stations are windows 98. The problem is: I have to run this stuff in small boxes, like some pentium 200mhz with 64-80mb ram, and in these machines the system is very slow. The html page takes about 70 seconds to be showed in the browser. I saw cpu and ram, and are all normal, even the mssql. Just the apache activity goes up to 70% cpu. We notice that while the php is running, anything happens and suddenly(after ~70 seconds) the page arises. Our php code is a kind of big, about 160kb, and the html is generated equally big. I am going to break the jscript stuff it in some small peaces, but will not help to much, I guess. Well, if someboddy could point out me a way, a tip or a tool to discover what the script is doing while I am waiting its response, or just an ideia, I would really thank you. Gustavo