Date   : Mon, 29 Dec 2014 11:54:16 +0100
From   : kortink@... (John Kortink)
Subject: New plaything ?

On Mon, 29 Dec 2014 09:43:21 +0000, Wookie <bbcmicro@...> wrote:

>On 28/12/14 13:11, John Kortink wrote:
>> Another surprise. Their 'legs' came in early too. More 'legs' than
>> you can shake a stick at.
>>
>> So ReCo6502Mini (as the project is named) can now be ordered. See also :
>> 
>>http://web.inter.nl.net/users/J.Kortink/home/hardware/reco6502mini/what.htm
>>
>> If you're interested, either contact me by email, or 'buy direct' (via
>> the bottom of the page, but please read everything carefully).
>
>Not bad only 3 days after Xmas...

I would have had them in 1 day if they had been a stock item,
but they're special order and the prediction was week 1 ... I
guess they were able to recruit some more elves.

>I don't know a lot about CPLD's so forgive me if this is a stupid 
>question... Can it be reprogrammed to be a Z80 or a 32016 for example?

No, it's too small to contain anything like that. It can
contain everything else though (glue logic, Tube ULA).

>That's assuming the code/firmware whatever its called that makes the 
>CPLD behave like a 6502 chip was ever written for it or is it 
>permanently emulating a 6502 chip ?

You probably did not notice that the 6502 is actually an
external chip.

CPLDs don't really support dynamic reconfiguration anyway.
They contain relatively few logic elements and use flash ROM
cells to hold their configuration. FPGAs, on the other hand,
contain many more LEs, and use (S)RAM cells, which are loaded,
at power-up, from (usually) external memory.

I could have built ReCo6502Mini with an FPGA, but it is not
supposed to be reconfigurable, at all. If you want that, you
can already use this (or, say, Jason Flynn's new thingy, if
you want to save a few bucks) :

http://web.inter.nl.net/users/J.Kortink/home/hardware/terasic_de0nano/index.htm

I'm just about to release a port of my 6502 Second Processor
design for a third development board (after DE1 and DE0 Nano),
which is this one :

http://www.terasic.com.tw/cgi-bin/page/archive.pl?Language=English&CategoryNo=165&No=830

I plan to put especially its SRAM and HDMI output to good use.
Some day. ;-)

>Also how do you change the clock speed ? via a *command I guess as I 
>can't see any dip switches?

Yes.

>I better dig my Master and RiscPC out of the loft, replace the battery 
>pack on the Master (I think that's all it needs, my Beeb+ is rather 
>sicker IIRC), get a new backup battery for my RiscPC (I removed it 
>before it leaked...) and get them both working to justify buying this :-)
>
>In case your wondering I use the RiscPC to copy software onto floppies 
>for the Master.

It's nice to know a Risc PC can still be useful. I concur. After
all these years it still has a prominent place here too ...


John Kortink

-- 

Email    : kortink@...         
Homepage : http://www.inter.nl.net/users/J.Kortink