Early 8051 variants with dual dptr (AMD?)

On 30.06.2016 05:28, Martin Riddle wrote:
> On Wed, 29 Jun 2016 22:52:02 -0400, Martin Riddle
> <martin_ridd@verizon.net> wrote:
> 
>> On Wed, 29 Jun 2016 11:19:31 +0200, Philipp Klaus Krause <pkk@spth.de>
>> wrote:
>>
>>> On 29.06.2016 09:49, Philipp Klaus Krause wrote:
>>>> Which were the first 8051 derivatives with multiple dptr? AFAIK the
>>>> Siemens 80C517 was the first with 8 dptr. I've read that AMD had an
>>>> early dual dptr vairant, but couldn't find a datasheet yet.
>>>> Which device was the first to use the following scheme:
>>>> DPL1 at 0x84, DPH1 at 0x85, DPS at 0x86.0?
>>>>
>>>> Philipp
>>>>
>>>
>>> I found the AMD 80C521, which looks like a good candiate for the first
>>> dual-dptr 8051-variant. But I'm not sure if there might be earlier ones.
>>>
>>> Philipp
>> I vaguely remember a Dallas Part with dual data pointers. Not sure if
>> it was among the first tho. Maybe 1996 or so.
>> keil has a list and data sheets on  their site.
>>
>> Cheers
> In the Phillips IC20 1997 data book the 80C52 has the feature list
> 'Second DPTR register' Dated 1996 Aug 16

Hmm, in &#4294967295;CSim the only Philips dual-dptr part is the P89C51R. I wonder
which one had dual dptr first.
AFAIK the P89C51R had DPS at 0xa2 and neither dpl1 nor dph1.

Philipp