Ok, here's how it works... (If you don't have an Amiga, don't do this!)
Get a filezapper type program. (NewZap DPU FileZap Hex etc...)
Look up your version of Imagine on the chart below.
Edit the executable at the bytes indicated in the chart. The block #s and byte #s are shown in decimal. The hex numbers in parenthesis are the hex versions of the block numbers. The bytes to modify are, of course, in hex. Replace the resolution you find there with the resolution you want. Then save the new file. (I don't have to remind you to keep a backup of Imagine on hand!)
Notice that Imagine automaticly doubles the vertical resolution for use in interlace mode. So, if you want vertical resolution of 462 then you must tell it to give you 231. (231 = 00E7 in hex)
Imagine Version # Horizontal Vertical
FP 1.1 Block 393 ($189) Block 83 ($053)
Bytes 220 & 221 Bytes 162 & 163
From 02 80 From 00 C8
(Example: To 02 BC = 700 in dec)(To 00 E7 = 231 dec)
FP 2.0 Block 497 ($1F1) Block 95 ($05F)
Bytes 328 & 329 Bytes 250 & 251
From 02 80 From 00 C8
INT PAL 2.0 Block 500 ($1F4) Block 94 ($05E)
Bytes 124 & 125 Bytes 42 & 43
From 02 80 From 01 00
FP PAL 2.0 Block 497 ($1F1) Block 95 ($05F)
Bytes 388 & 389 Bytes 244 & 245
From 02 80 From 01 0
INT 2.9 Block 1561 ($619) Block 119 ($077)
Bytes 486 & 487 Bytes 480 & 481
From 02 80 From 00 C8
FP 2.9 Block 1529 ($5F9) Block 95 ($05F)
Bytes 82 & 83 Bytes 168 & 169
From 02 80 From 00 C8
FP PAL 2.9 Block 1529 ($5F9) Block 95 ($05F)
Bytes 146 & 147 Bytes 162 & 163
From 02 80 From 01 00
FP 3.0 Block 1667 Block 126
Offset +60 Offset +425
Abs pos 853564 Abs pos 64937
Current value $0280 Current $64
FP 3.1 Block 1765 Block 131
Offset +424 Offset +343
Abs pos 904104 Abs pos 67415
Current value $0280 Current $64
Block + Offset is commonly used with most disk editors, but some use the Absolute Porition instead. Remember to divide the height of the screen by 4 first, and that you can't use values higher than 127 due to Impulses use of signed character storage. 127 will give you screen height of 508. I don't think its easily possible to hack Imagine to use an unsigned character to get a higher screen size. Anyone?
One Final Note: Imagine PC users have a whole different program than Amiga users. This modification will not work on the PC version. I would guess that a similar modification for the PC version would be more complicated, given that VGA modes are more complicated than Amiga modes.
Last Update: July 13, 1995