I realise this is three years old, but do you recall if this was a 1MB cache?
Cache for the 6100 series was 256K.
Not all of it. There were 512k and 1MB caches available.
See here for example
Ah...so yours was a rhetorical question.
No, I wanted to check if the specific one photographed here was 1MB or not.
It appears to be a 256k module. According to Chipmunk, the "256" numbers at the end of the code on each of the individual chips means each one is 32kbits x 8, which means each chip is 32kBytes. Since there are eight chips, that makes a 256k module. See for example: