Bad ROM chip in E ?

[exxos]

The message is obvious in TOS206.. But does anyone actually know which side of the bus "E" actually refers to ?

[stephen_usher]

Logically this would be referring to the 6 ROM set, so E would be ROM 5 in that case. So, High?

[dml]

Is this not supposed to be indicating EVEN/ODD byte in the 16bit word? The ROMs are paired.

The individual ICs in a multi-rom set are sometimes physically marked Ex/Oy in pairs (have seen labels with pencil markings on a couple) but the ROM code doesn't necessarily know how many ICs are in use so even/odd is all you get.

But yes - [E]ven would be the high byte in the word (byte 0 would be even but also the first or high byte in a bigendian word). Does not indicate which IC though in a larger set...

It also seems likely that it will report faults in 'E' before it notices faults in 'O' so the whole word could be wrong and it will only report 'E' and stop. :shrug: