[Techtoolslist] Crystal Castles ROM Address Range

[Clay Cowgill]

Crystal Castles uses so-called bank selected memory, meaning that only a
portion of the total ROM is visible at any given time from a particular
address range.


>From a quick glance at the schematic, it looks like writing either a 0x00 or

0x01 to address 0x9E87 will switch banks of ROM.  Put another way .1f and
.1h will appear in memory *or* .1k and .1l.  0xA000 (.1k and .1h) and 0xC000
(.1l and .1f)

You can write 0x9E87 with 0x00 or 0x01 from the 9010 controls to manually
switch banks and view/checksum ROM contents.

-Clay


> -----Original Message-----

> From: techtoolslist-bounces at flippers.com 

> [mailto:techtoolslist-bounces at flippers.com] On Behalf Of 

> Justin Johnson

> Sent: Tuesday, November 20, 2012 7:06 PM

> To: techtoolslist at flippers.com

> Subject: [Techtoolslist] Crystal Castles ROM Address Range

> 

> This is my first post.  I'm learning how to use my Fluke 9010 

> and ran into a problem doing a CRC check on some of the ROMS. 

>  Looking in the  

> MAME source code I found the address ranges for each ROM(see 

> below).   

> ROMs 304 to 305 work fine but the address appears to be out 

> of range for ROMs 101 and 102.  ROM 101 according to the 

> source code should start at 10000-11FFF. What address should 

> I be using?  Where am I going wrong here??