Date   : Sun, 12 Apr 2009 02:12:34 +0200
From   : kortink@... (John Kortink)
Subject: Faster, faster

On Sun, 12 Apr 2009 00:57:45 +0100, "David Hunt"
<dm.hunt@...> wrote:

>[...]
>
>> The 'remake' does need the box and the original Tube ULA
>> from an existing 6502 second processor. I.e. (as yet ...)
>> it is not standalone, but either a replacement or an
>> upgrade. This is, and will probably remain, its main
>> purpose.
>
>[...]
>
>Wow! When is this available? How much will it cost?

TBA. Probably soon and somewhere between 65 and 75 Euro.

>Are you fixing the clock at 14MHz or are you going to allow it to go to
>20MHz?

The clock is somewhat variable, although the processor
always slows down to 3 MHz when it accesses the ULA.

Options for the processor will probably be 3, 4, 14
MHz and some special setting. Experiments reveal that
even the 10 MHz WDC that I had lying around will go up
to around 18 MHz, and the 14 MHz one seems similar (20
MHz boots but is unstable).

>I recall an WDC licensed FPGA IP core implementation running at 133MHz, I
>got the guy's business card buried somewhere around.

Sure, but then you might as well throw everything into
an FPGA. And it won't be cheap.

>Personally, I'd like a 6502 SP with a bit more bite on the performance
>front, I have Sprow's ARM7/32MB internally, but I've not seen a 6502 SP
>emulator for it so I just mess around with a few bits of BASIC and ARM asm. 
>
>Could you replace the ULA with a CPLD ? That would remove the need to
>salvage them from (working) vintage boards.

Yes, but I don't want to do it now.

>After being in Asia for months sat inside clean rooms looking at the latest
>and greatest in display technology, Beeb stuff is positively refreshing ;)

It's nice to be almost genuinely excited about 14 MHz,
isn't it ...


John Kortink

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