I know this is an old topic, but as it contains some things that are incorrect, I couldn't resist to reply in case someone is looking for answers on it.
The megatouch XL with Telco mother board doesn't boot from cdrom. It boots from U13 on the IO board which is a rom flashdisk. U12 is an eprom that extends the pc bios so that it recognises U13 like a normal harddisk.
U11, the thicker dallas chip is an NVRAM of 32K. It's used to store settings and hiscores. It's not having a real time clock, it's simply a memory chip which keeps it's contents when the power is removed.
There are 2 jumpers JP1 and JP2 that are eprom enable and nvram enable. The jumper JP1 needs to be installed if you want the Telco motherboard to boot from that rom flashdisk. The dos on that flashdisk is Romdos. It creates a small ramdisk as D drive. After that, it installs the dos cdrom driver. The cdrom get's the drive letter F. Some exe's are loaded from the romdisk (among them the dos touchscreen driver) After that, the system jumps to drive F and launches a batch file called launchit.bat.
So, the boot drive not found error indicates that there is problem with the motherboard not finding the io board romdisk. Frequently, the cause of this are oxidated contacts on the riser card or on the io card. It is possible to disable the rom flashdisk and boot from a harddisk or compact flash card with a "cf to ide" adapter. The game runs fine on freedos. If there is a problem with the io card romdisk, you might also have problems with the nvram, so it won't keep it's setup and high scores. If it can't locate it's dallas security dongle, the game won't start and you will see it going in a loop.