I have to wonder how much of the original assembly source looked a lot more succinct than whatever's in OpenRCT due to the use of macros. Looking up his gameography on Mobygames, Chris had been writing stuff since 1984 when RCT came out in 1999, it's hard to imagine he was still writing every single opcode out by hand given that I had some macros in the assembler I was fooling around with on my c64 back in the eighties.