Date   : Wed, 02 Nov 2005 08:25:46 -0000
From   : "David Harper" <dl.harper@...>
Subject: Re: Adding copro support to BeebEm

Jules Richardson <julesrichardsonuk@...> wrote:

>>>> I do have a scan of the ACW 32000 assembler manual here - but it tells
>>>> you to go get a copy of the natsemi 32000 instruction set manual from
>>>> your local Acorn dealer, grrr! :-)
>>>
>>>
>>> Ditto grrrr! The 32016 assemble manual essentially only tells you
>>> what parameters to pass to the *as command and nothing else!
>>
>>
>> The full data book (for all the NS32xxx CPUs) is available at 
>> http://bitsavers.org/pdf/national/_dataBooks/1986_NS32000_dataBook.pdf
>>
>> It is a scan of a 1300-page document, so about 70Mb. I hope you have fast 
>> broadband!
>
> I think Jonathan mentioned that he has this though and was getting 
> somewhat lost in all the data. I'm sure there used to be a better document 
> specific to the 32016 on bitsavers at one point, but I can't see it now.

You could be right, though in my (admittedly very limited) experience 
semiconductor manufacturers are inclined to tell you everything or nothing. 
You have to rely on independent sources for digests.

As I am sure you know, there is a simple chart at:
ftp://ftp.comlab.ox.ac.uk/pub/Cards/txt/32016.txt
but that only gives the instructions (and chip pin-out) not the opcodes.

I agree that the full databook is somewhat daunting. However the 32016 
itself is covered in pages 2-275 to 2-337 (pages 348 to 410 of the whole 
book), and of these you will be able to skim Section 3 (pp 2-288 to 2-319) 
fairly superficially and, unless you are going to play around with the 
hardware, you will be able to ignore Section 4 (pp. 2-320 to 2-333) 
altogether. OK, it would be a fairly major undertaking, but you should be 
able to work out from that how the processor's language works. From there it 
ought to be a pretty easy job (though a very tedious one) to write a simple 
assembler for the thing.

The 32016 is a complex chip, but not much more so that the 80186 - the 
databook for that extends to 48 pages. But then lots of other people have 
written books about the 8086 family in (relatively) simple English.

However, once you have an assembler, what do you do for an operating system? 
I seem to recall that the 32016 board came with a system called "Panos", but 
I don't know anything about that. The obvious thing would be to port Linux 
to it, but I am sure that would be a non-trivial exercise!

Best of luck!

David Harper