Re: A86: New Opcodes?


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Re: A86: New Opcodes?




This page is for both the z80 and the z180 (the z180 has a few added
instructions).  If you read carefully, it says when an instruction is
only for the z180, but, yeah, I should have said something on my site.
I think that page has a lot of great info, though. :-)  Did you read the
part on the interrupts?

linger richard nathan wrote:
> 
> I was looking at the link on Dux's site which points to a Zilog page full
> of Adobe Acrobat files containing info on the Z80.
> (http://www.zilog.com/frames/develope/z80180um/z80185.html)  In the
> Chapter that outlines the Instruction set, there are several Mnemonics
> that looked totally unfamiliar to me.  Here are a few of them:
> 
> MLT, TSTIO, SLP, OTDM, OTDMR, & TST.
> 
> SLP puts the processor into some kind of "Sleep Mode" where it executes
> NOPs until an interrupt occurs.
> 
> TST works just like AND except it doesn't affect the A register, it only
> affects the flags.  I guess TST is to AND as CP is to SUB.
> 
> It said that MLT took the individual 8-bit registers in a register pair
> and put the 16-bit product in that pair.  For example D*E -> DE.
> 
> In the older references I looked through at the library, no multiplication
> instruction was even mentioned.  In fact they specifically said the Z80
> didn't have a multiplication instruction.
> 
> The documents were from the Z80185/195 Zilog User's Manual.  It this a
> newer version of the Z80 that has instructions incompatible with the Z80
> in the TI-86.  Or are these opcodes valid on the TI-86?  If they are, that
> MLT looks like a very useful command.
> 
> If these are bogus opcodes, you should make not of this on your page, Dux.
> 
> Nathan Linger


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