[Coco] 4 Port MPI PCB artwork (so far)

[Bill Nobel]

Question,, for a newbie to advanced hardware. I have done peripheral stuff, (printers, rs232, etc…) and want to go further. I have ordered the parts to Grant’s 6 chip comp.  I want to take it to the extent that Kip has and more compatibility, and more advanced. The level of Coco2 with no 6847 to start with. (need to ad at least the 68B21 that handle cass./joy). That will open the door to Drivewire and the most part of Nitros9 Level 1.

  From that point I have come across some MMU circuits that I want to look into. Not compatible with current Coco3, but can be better (once video alternative gets resolved)

 I need to bug Kip on to letting the schematic on his version of 58K ram be public (to enlighten me for ram workings vs rom).

Bill Nobel
.
> On Mar 4, 2015, at 10:38 PM, RETRO Innovations <go4retro at go4retro.com> wrote:
> 
> On 3/4/2015 3:50 PM, camillus blockx wrote:
>> That's ok Jim
>> 
>> Please keep me posted.
>> Do you have knowledge of the SDMC ( floppydrive emulator), and the PCLD's
>> that is used in it, I was wondering of merging the two together in one?
> You can, but if you assume that the project uses *most* of the CPLD space it has, you have to add them together to find a part suitable for merging.
> 
> SO, this project uses a 9572, which has 72 macrocells and it uses 51 IO lines.  The CocoSDC needs a 9572 as well and uses up to 34 IO lines..  Mine is ~50% full, I assume Darren's is 100% or close. Thus, to merge the designs, you need 72+36 macrocells, and you need 51+34 IO, so you're looking at a 95144, but more than a TQ100 part, so you have to go with 144 pin part.  CPLDs gets somewhat expensive as the macrocells and pin count go up.  The cheapest I see that part is $7.50, and Darren's CPLD costs $2.26 and mine costs $2.66, so it is actually cheaper (and easier) to leave them separate.
>> 
>> 
>> Can you btw tell me where you found the connectors?
> In expectation of this project, and to get a good deal on them for other people and such, I made a bulk order from a firm I typically buy my Commodroe 22/44 connectors from.  It's a business purchase, with wire transfers and such, not a retail place.
> 
> But, I have 1000 of them coming, so I'll put a bunch in the store, and try to price them economically so everyone can have a batch if they want.
> 
> 
> 
> 
> -- 
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco