Jet Set Willy Home -> Jet Set Willy -> The Softricks engine
The Softricks JSW Editor Mark II produces a JSW game with a slightly different engine from the normal JSW one. These are the changes:
| Address | Comments |
|---|---|
| 86B0h | Call to copy protection code is replaced by a jump to the start of the game. |
| 8800h | The object table moves from A400h to FE00h. |
| 88F3h | The length of the scrolling message is increased so it includes the following "Objects collected" message as well. This is part of the attract mode. |
| 88F9h | After the message has finished scrolling, jump to the attract mode rather than restart the title screen. |
| 892Eh | The instruction RES 7,L has been replaced with two NOPs. This causes the guardian table to be treated as 8 pages rather than 4, doubling the number of guardians in the game. |
| 8AC2h | Automatic pausing is disabled. |
| 8C01h - 8C28h | New "death" routine that draws the title screen |
| 8F1Ah | The object table is now at 0FE00h; the object count is at 83FFh. |
| 95B3h | The page for the toilet sprite is now 9Fh, not A6h. |
| 96F4h - 979Ah | Unused JSW code is replaced by what appear to be random data. |
| 979Bh - 97E8h | The code to provide attract mode. |
The major change, then, is that the guardian table doubles in length. The data that were in the range A400h-A7FFh (the object tables and a couple of sprite pages) have been relocated.