[Info-vax] Assembly languages, was: Re: OT: PDP-11 history in arstechnica

[Bob Eager]

On Thu, 17 Mar 2022 00:48:41 +0000, Simon Clubley wrote:

> On 2022-03-16, Rich Alderson <news at alderson.users.panix.com> wrote:
>>
>> ALL the PDP-10 mnemonics for instructions which access memory have the
>> same form (taking MOVE as a canonical example):
>>
>> 	MOVE	load accumulator with contents of memory at effective 
address
>> 	MOVEI	load accumulator with immediate effective address 
calculation
>> 	MOVES	load accumulator with swapped halfwords of contents of 
memory
>> 		at effective address
>> 	MOVEM	store accumulator into memory at effective address
>>
>> Look at the last character of the instruction.  You don't even have to
>> remember the difference between "load" and "store".
>>
>>
> Doesn't anyone else find it strange that the mnemonic across all
> architectures is some variant of MOVE or MOV instead of COPY or CPY ?
> 
> After all, you are not destroying the contents at the original
> location/register when you copy it to the target location/register.

And then you have the PDP-8, which doesn't have MOVE. But DCA clears the 
accumulator when copying its contents.



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