Undocumented 8085 Flags And Instructions

Undocumented features is quite common. sometimes it is a subroutine used by other functions with a link supplied to them for testing purposes. The problem of using them is that they may disappear on change in the next revision.

Long time ago I bought a XT and I discovered additional functions only to realize that the chip was really intended to be a 186 but was never released and replaced with a 286.

I you can use the functions, go for it.

Thanks for the reply !

From where we can get these undocumeted codes ?

why the manufacturers not releasing them along with the instructionset?

Sometimes the function had a flaw (example division by zero or range problems) and therefore not safe for them to make available.

I have some 8085 documentation somewhere, have to go through boxes in my storeroom though. If i find them I will post or mail you detail.

Thanks again but i already had those undocumented codes of the 8085

specified by the link.

the undocumented codes for higher versions may be helpful but i dont have a collection of them .....

I made a 8085 decompiler in ±1983 and had some inside information.

I will not be able to supply the micro code but may be able to supply calling conventions and register status on return.

I think there were more than one version A, B, A2 . . . .

gr8 i have also made one too.

its code is written in C and its able to decompile almost all instructions except undocumented ,becoz i was not much aware of the undocumented codes .....

Such informations are really inspiring