[Coco] Introduction

[Kip Koon]

John,
I concur with Richard's comment below.  I understood everything you said and
I for one do not mind long emails.  I really get into them.  :)  The more
explanations, the better.  I'm always up for learning more, hardware or
software.  I might as well use my free time for constructive things and I
can't think of anything more constructive and fun then developing for the
Cocos, especially the Coco 3!  I know I'm not up to par, yet, for developing
an FPGA based CPU, much less an FPGA based system on a chip like you and
others on this list have.  :)  Keep up the great work.  
Kip

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
Behalf Of Richard E. Crislip
Sent: Sunday, February 24, 2013 3:45 PM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] Introduction

On Sunday, February 24, 2013 08:35:28 AM John Kent wrote:
> Hi Jayeson,
> 
> The Spartan 3 Starter board from Digilent-Inc has 1MByte of high speed 
> static RAM on it that can be configured as 256K x 32 bits. It would be 
> better as a logic analyzer than the XuLA board, as the RAM is 
> asynchronous and doesn't need refresh cycles.
> 
> It is possible to buffer the input on the XuLA board, with block RAM 
> but then you have the problem of crossing clock domains between the 
> input sample clock and the SDRAM clock. I'm not sure if that is a big 
> problem with dual ported block RAM. Dave Vanden Bout from XESS did 
> tell me one of the original applications intended for the XuLA board 
> was as a logic analyzer.
> 
> The XuLA board does have the advantage that you have a USB connection 
> to the PIC chip on the board so it's much faster transferring data 
> than using a RS232 port.
> 
> Both the XuLA and Digilent-Inc need level conversion for the inputs 
> but that is self evident.
> 
> I'm sorry for the length of the last email. I was pretty much 
> repeating what has already been stated on the list.
> 
> John.
> 
> On 24/02/2013 11:43 PM, Jayeson Lee-Steere wrote:
> > John,
> > 
> > Thanks for the info. You are getting years ahead of me! I was 
> > thinking that attaching one to the Coco cartridge connector port and 
> > programming the FPGA to log bus activity into the SRAM would be good 
> > for creating accurate timing reference for software emulations. That 
> > is sounds fairly simple and in my comfort zone. Anyway, I ordered the
200K gate version.
> > Still need a prototyping board with the card edge though...
> > 
> > - Jayeson

Don't be sorry! Even I understood most of it 8-). I haven't even touched a
FPGA. Excellent explanation. When you mentioned Switch/Case constructs, I
even know what that was all about. You see them in the Bash Shell and C++
8-).

Richard

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