[Coco] ROM Cart registers

[Mark Marlette]

Jim,

The SuperIDE's firmware is fine. It is beyond a mature device, it has moved to legacy support here. This device was released in 2004 and has been tested on almost every disk controller ever made for the CoCo. 

The sIDE is FULLY decoded and does use the SLENB~ signal to remove ALL devices in SCS region of the memory map. It does not rely on being slot dependent, the slot, when in the MPI, is ONLY required for the boot ROM. After boot, when booting from the sIDE and in the MPI, you can move the switch or software poke off of the sIDE to the floppy controller or whatever slot you would like and still have access to the CF/ATA devices.

It is following the Tandy rules for SCS as I designed it and understand them.  

As I watch the list and the thread out of the corner of my eye, I thought you indicated that your MPI was functional?

>From your posts here and questions of SLENB~, I wonder if the sIDE works in your device?

A true test is backing up a device with verify in your MPI. We tested 12-24hrs, without an error, many times.

Boisy created SuperDriver in conjunction of the sIDE, we both pushed the limits of each others capabilities and the CoCo's bandwidth with an ATA device. With hardware and software lessons learned it will go to a new level of capability in Gen 3.

The current generation goes ~300% faster. So if your MPI won't run the sIDE, it will not run Cloud-9's Gen 3 devices.

Regards,

Mark Marlette
http://www.cloud9tech.com
mark at cloud9tech.com

________________________________
From: RETRO Innovations <go4retro at go4retro.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com> 
Sent: Sunday, January 31, 2016 2:33 PM
Subject: Re: [Coco] ROM Cart registers


On 1/31/2016 2:15 PM, Darren A wrote:
> On Sun, Jan 31, 2016 at 12:47 PM, RETRO Innovations <go4retro at go4retro.com>
> wrote:
>
> I am struggling to  think of a valid reason to strobe SLENB* when SCS has
>> not been strobed and the address is located in the $ff40-$ff8f range.
>>
>> Jim
>>
>
> It means you're claiming the address space for exclusive use and you don't
> need to make the effort to write an "MPI aware" driver. You completely
> decode addresses yourself so the device is always active, even when the MPI
> slot containing it is not. By asserting SLENB* you prevent other devices
> (those that require SCS) from responding and creating a conflict,
> effectively locking them out.
>
> SCS only covers the $FF40-FF5F range.  $FF60-FF7F were assigned by Radio
> Shack to various products. $FF80-$FFDF are allocated to the GIME on the
> CoCo 3.
>
> - Darren
>
I did not realize SCS stops at ff5f.  I'll update my code.  I was 
wondering why the registers failed the other night to respond to an 
access at $ff6x

I also understand the reasoning now, but it will make it difficult to 
co-exist with such products.

Jim




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