7 Sep
2010
7 Sep
'10
10:24 a.m.
On 2010 Sep 7, at 9:29 AM, maurice smulders wrote:
I think I have the NEC databook containing the series.
Do you need a
scan?
Thanks, but no, I'm not planning on doing anything with the MCU (the
photocopier was being discarded and the MCU is internally programmed).
I was just interested in knowing something of the architectural/family
provenance of the MCU as I had never run across it before.
On Mon, Sep 6, 2010 at 5:13 PM, allison <ajp166 at
verizon.net> wrote:
> On 09/06/2010 02:34 PM, Brent Hilpert wrote:
>>
>> On 2010 Sep 6, at 5:56 AM, allison wrote:
>>
>>> On 09/05/2010 10:06 PM, Brent Hilpert wrote:
>>>>
>>>> I just ran across an NEC D75008 microcontroller in a small photo
>>>> copier
>>>> ca. 1990. According to a search it is a 4-bit microcontroller.
>>>>
>>>> Idle curiousity, but does anybody know if this has any inheritance
>>>> from
>>>> or relation to better-known microcontrollers such as the TMS1000,
>>>> that is,
>>>> is it NEC's version of something better known?, or is it NEC's
own
>>>> architecture?
>>
>>> No, ?it is NEC unique. ?For 4 bitters that is usually the case. ?
>>> it is a
>>> much more expanded
>>> design closer to modern PICs with many variants having LCD driver on
>>> board.
>>
>> OK, a family I had never run across before. Found a datasheet for (by
>> appearance) a descendant (D75112/6). Looks like they took a cue from
>> the
>> 8080 family - the register set is nearly identical but in 4 bits,
>> with
>> register pairs BC, DE, HL to make 8-bit registers.
>>
>
> Many of the 4bit MCUs did that. ?The instruction set is is similar to
> 8080
> and different since it has
> skip on condition and typical Harvard oddities and additions for
> tables and
> inline constants.
>
> The family closest to it is the 1980s ucom75.