Randy Linden, the port's sole programmer, initiated the port of Doom for the Super NES on his own initially, as he was fascinated by the game.
Since Doom's source code was not yet released at the time, Linden referred to the Unofficial Doom Specs as a means of understanding the game's lump layout in detail. The resources were extracted from the IWAD, with some (notably sprites such as the player's sprites and the original status bar face sprites) unused due to technical limitations.
According to an interview, due to lack of development systems for the Super FX, Linden wrote a set of tools consisting of an assembler, linker, debugger, dubbed the ACCESS, on his own Amiga before beginning development of the port proper. For the hardware kit, he utilized a hacked Star Fox cartridge and a pair of modified Super NES controllers plugged into the console and connected to the Amiga's parallel port. A serial protocol was used to further link the two devices.
After developing a full prototype, he later showcased it to his employer, Sculptured Software, which helped him finish the development. In the interview, Linden expressed a wish that he could have added the missing levels; however, the game, already the largest possible size for a Super FX 2 game at 16 megabits (approximately 2 megabytes), only has roughly 16 bytes of free space. Linden also added support for the Super Scope light gun device, the Super NES mouse, and the XBAND modem for multiplayer. Fellow programmer John Coffey, himself a fan of the Doom series, made modifications to the levels, but some of those modifications were rejected by id Software.
I was lucky enough to work with Randy for quite a few years at Microsoft.
Incredible developer. He also made the Bleem! PlayStation emulator.
Funny enough none of his coworkers ever bothered to look him up online until after we all stopped working together at which point we all learned we'd been working with programming royalty.
I know that Wolf3D on the SNES uses Mode 7. Not for the walls or sprites, but for the entire screen. The graphics are rendered into a background tiles with a resolution of like 175x100 or something, then scaled up with Mode7 to fill the 224x192 screen. (those aren't the exact numbers, but you get the idea)
The "mosaic trick" is a way to perform horizontal pixel doubling in hardware rather than software. And to do this trick, you turn on the SNES's Mosaic feature, scroll 1 pixel to the left every other scanline, and scroll upward one pixel after each two scanlines have been drawn.
Normally the SNES mosaic feature just the top-left pixel of a 2x2 square into that entire square. But the trick makes a different set of pixels get doubled horizontally on the next scanline.
It requires a different arrangement of pixels than the normal way of drawing tiles. A tile containing these pixels:
01234567
becomes this when viewed on two scanlines:
00224466
11335577
Actually performing these scroll writes does not require any CPU intervention because you use the SNES's HDMA feature to do those scroll writes.
Randy Linden, the port's sole programmer, initiated the port of Doom for the Super NES on his own initially, as he was fascinated by the game.
Since Doom's source code was not yet released at the time, Linden referred to the Unofficial Doom Specs as a means of understanding the game's lump layout in detail. The resources were extracted from the IWAD, with some (notably sprites such as the player's sprites and the original status bar face sprites) unused due to technical limitations.
According to an interview, due to lack of development systems for the Super FX, Linden wrote a set of tools consisting of an assembler, linker, debugger, dubbed the ACCESS, on his own Amiga before beginning development of the port proper. For the hardware kit, he utilized a hacked Star Fox cartridge and a pair of modified Super NES controllers plugged into the console and connected to the Amiga's parallel port. A serial protocol was used to further link the two devices.
After developing a full prototype, he later showcased it to his employer, Sculptured Software, which helped him finish the development. In the interview, Linden expressed a wish that he could have added the missing levels; however, the game, already the largest possible size for a Super FX 2 game at 16 megabits (approximately 2 megabytes), only has roughly 16 bytes of free space. Linden also added support for the Super Scope light gun device, the Super NES mouse, and the XBAND modem for multiplayer. Fellow programmer John Coffey, himself a fan of the Doom series, made modifications to the levels, but some of those modifications were rejected by id Software.