Hardware info
San Francisco Rush and San Francisco Rush: The Rock runs on Atari's "Flagstaff" hardware:
* 192MHz R5000 main CPU (system clock 48MHz)
* Galileo GT64010 system controller
* National Semiconductor PC87415 IDE controller
* SMC91C94 ethernet controller
* ADC0848 8 x A-to-D converters
* 3dfx FBI with 2MB frame buffer
* 2 x 3dfx TMU with 4MB texture memory
* Midway I/O ASIC
* 8MB DRAM for main CPU
* 512KB boot ROM
* 33MHz TMS32C031 audio CPU
* 8MB ROM space for audio CPU
* 512KB boot ROM
San Francisco Rush 2049 and its revisions run on Atari's "Denver" hardware:
CPU board:
Durango - RM7000 or RM5271 @ 250-300MHz, 8-32MB RAM
Sound I/O board:
Denver SIO - ADSP2181 @ 33MHz, no ROM, 4MB RAM
Video board:
Voodoo 3
This hardware is very different from one another, so San Francisco Rush cannot be upgraded to 2049, and vise versa.
Each version of both games has its own security data stored on a Microchip Technology PIC16C57. Denver hardware has its security PIC located at U27 on the Sound I/O board, and Flagstaff's is at U96. A mismatched or missing/damaged PIC will prevent the game from starting up. On Denver hardware, "IOASIC" will repeat on the 7-segment display if this is the case. Legitimate security PICs are protected with the security bit and are unable to be dumped by conventional means.
Hard Drive
As with any 20+ year old hard drive, the original drives in these machines might have corrupt data, freeze during gameplay, or not work at all. Both games use a standard IDE 3.5" HDD to store the bulk of the game data.
San Francisco Rush and San Francisco Rush: The Rock
San Francisco Rush and San Francisco Rush: The Rock shipped with a 1.2GB Quantum Fireball drive. These drives are notorious for being unreliable, and a replacement solution should be considered if your machine is still running one.
Compact Flash Card
The recommended solution for this game is to install a Compact Flash card in place of the hard drive. This increases reliability and loading speed, and decreases noise and the amount of moving parts. Just about any CF to IDE device will work, the best one is known as the "CF-IDE40". This one plugs directly into the CPU board, sparing the need for an IDE cable.
IDE Hard Drive
An easy solution is to simply replace the hard drive with another one. Manufacturing of IDE hard drives ceased late 2013, however, so any drop-in replacement you find will be close to 10 years old already (as of 2021). If you have a pile of them sitting around though, it won't hurt to put it to use.