[Coco] 256K SuperROMPak (32 Banks)

[RETRO Innovations]

On 2/19/2015 5:13 AM, Mark McDougall wrote:
> On 11/02/2015 3:53 PM, Chad H wrote:
>
>> These are the posts I came across that made me realize it wasn't 
>> going to
>> be so simple to tie into these lines.  We would need extra logic
>> circuits/IC's....
>>
>> http://comments.gmane.org/gmane.comp.hardware.tandy.coco/32296
>> http://comments.gmane.org/gmane.comp.hardware.tandy.coco/32888
>
> Yup, that'd be my mistake back then! ;)
>
> Coincidentally, I'm planning on designing a flash cart in the near 
> future, that will be programmable from the Coco in-circuit. It will 
> also likely have a small serial EEPROM. There'll be a very limited run 
> sold as a Lode Runner cartridge initially, but ultimately it'll be 
> (re)programmable as a generic flash cartridge.
>
> No ETA, treat it as vapourware.
>
> Regards,
>
Sorry to bring up an older subject, but I seem to have some spare copper 
on the MPI, and I thought I'd at least drop a CPLD and FLASH footprint 
on the board for later efforts to create a writeable flash cart

Reading the above forum posts, I gather that I need to:

  * grab address lines 0-15 and q and e and r/w to decode the CTS line
    by myself.
  * Create a register that turns off "write to cart space" functionality
    unless the user specifically asks for it.

Thus, i think I need to bring the following into the CPLD:

  * a0-a15 (16)
  * d0-a7 (8)
  * r/w (1)
  * e (1)
  * q (1)
  * reset (1)
  * flash_ce (1)
  * flash_oe (1)
  * flash_we (1)
  * scs (1) (not sure I need it, as it looks like I can just figure it
    out from the other lines...)

Any others?

I know it's feature creep, but adding the footprints takes no time, and 
I wanted to get it in before I send the PCB off for proto etching (5 
boards).  Any help would be appreciated.  I sent a note to Mark about 
it, but have not yet received a response.

Jim


  *





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