[Coco] CoCo Game Master Cartridge developer offer

John W. Linville linville at tuxdriver.com
Fri Oct 20 18:34:45 EDT 2017


I see no need to replicate this between here and the Facebook group. If
anyone needs help finding the corresponding discussion on Facebook,
then feel free to drop me a line...

John

On Fri, Oct 20, 2017 at 05:01:35PM -0500, Zippster wrote:
>  I'd hesitate to comment here, but since I have been specifically mentioned...
> 
> "His design is a more susceptible to that problem than some other designs, since
>  it is more elaborate and probably not appropriate for shipping a copy of the audio 
> hardware on cartridge with every game that supports it."
> 
> Perhaps not, but there is a large amount of flash available on the card that can easily
> be written by the CoCo, and games can be easily distributed by other means and 
> flashed to the cart, which could hold quite a few of them.
> 
> In addition, the PSG interface is flexible, compatible with disk based software and 
> Drivewire via HDB-DOS without modification, and provides digital joystick ports and
> and external audio jack for better sound quality at a price not a whole heck of a lot 
> greater than a single, stand alone game cart.
> 
> I'm not sure why having more than one sound option out there is seen as "the great race
> for CoCo audio supremacyā€¯. 
> 
> Why isn't there room for more than one type of sound enhancement?
> 
> More options are better for the community and developers.   I'm glad you are offering your
> hardware to them to work with.
> 
> 
> - Ed
> 
>  
> 
> 
> > On Oct 20, 2017, at 4:19 PM, John W. Linville <linville at tuxdriver.com> wrote:
> > 
> > I'm not exactly sure when the great race for CoCo audio supremacy
> > began. I remember ruminating about the possibilities of adding audio
> > to a CoCo cart for at least a couple of years now, maybe more. It's
> > odd, it seems like not too long ago when just the idea of a basic
> > ROM cart for the CoCo seemed out of reach...
> > 
> > Anyway, somewhere along the way (especially after I demo'ed some
> > audio tech for CoCoFEST!) the idea caught on and suddenly everyone
> > wanted enhanced sound on their CoCo.  The main problem being, everyone
> > wanted their own version of a solution. Some of those ideas were odd
> > or questionable from the beginning, others had some legs but lacked
> > obvious purpose, while others remained plausible but with limitations
> > due to their own designs. In short, some of the proposed CoCo audio
> > solutions were more "sound" than others.
> > 
> > Earlier this week, one of the stronger contenders became available
> > "for experimenters and assembly language programmers who would like
> > to work with digital sound on the CoCo". The backer of that project,
> > Ed Snider, knows that software for new hardware can present a "chicken
> > and egg" problem. His design is a more susceptible to that problem
> > than some other designs, since it is more elaborate and probably not
> > appropriate for shipping a copy of the audio hardware on cartridge
> > with every game that supports it.  Nevertheless, even if a certain
> > design enables a game cartridge to economically ship with its own audio
> > hardware (removing the need to acquire the hardware in advance), there
> > are those that will insist on having such hardware before committing
> > to develop uses for it. The availability of the Game Master Cartridge
> > design in MAME alleviates this desire for some potential developers,
> > but apparently not for all.
> > 
> > So with that in mind, I am hereby offering an opportunity for folks
> > to acquire their own Game Master Cartridge hardware by pre-ordering
> > through me. A pre-order is merited based on the fact that I had never
> > intended to offer the Game Master Cartridge as an independent product,
> > but instead as a finished product shipping with a release game. So,
> > consider this as an offer for developers and other technical-minded
> > folks that are looking to experiment with the SN76489 on the Tandy
> > Color Computer.
> > 
> > I am offering the following options:
> > 
> > 	Bare PCB		 7.00
> > 
> > 	PCB + parts kit		12.00
> > 	(ROM socket, no ROM or EPROM)
> > 
> > 	Assembled card		20.00
> > 	(ROM socket, no ROM or EPROM)
> > 
> > 	Assembled cartridge	30.00
> > 	(ROM socket, "P-Touch" label)
> > 
> > If you wish to acquire one of the options offered above, please contact
> > me ASAP via email to "linville at tuxdriver.com" with a subject of "CoCo
> > GMC developer offer". Iff and when I acknowledge your email, you may
> > then pay for the item in question via Paypal to my email address. Do
> > not pay me unless and until I have explicitly accepted your inquiry, as
> > I may not have the capacity to handle every request in a timely basis.
> > 
> > Along with the SN76489 audio hardware, this cartridge includes ROM
> > "bank switching" hardware that is compatible with what was used for
> > Predator and Robocop. The bank switching hardware portion of the
> > design is documented in "Breaking the 32K Barrier" by Greg Zumwalt,
> > The Rainbow, June 1990. The bank switch register is addressed at $ff40.
> > 
> > The SN76489 audio hardware is addressed at $ff41. It is clocked
> > at 4 Mhz by an onboard oscillator. The oscillator speed value
> > could be changed for those determined to play very low notes
> > (e.g. octaves 0 and 1), but is sufficient for a wide variety of musical
> > entertainment. Tools exist for working with this chip on a variety
> > of other retro platforms, and some are beginning to be available for
> > the CoCo as well.
> > 
> > Since this hardware design was designed to be used as a ROM cartridge,
> > the address decoding makes use of the SCS! signal. This causes the card
> > to conflict with most (or all) floppy drive controllers, the CoCoSDC,
> > and probably some other hardware. These devices can coexist in the
> > same machine through use of the Multi-Pak Interface and its ability to
> > multiplex the SCS! line. I understand this limitation to be in common
> > with some of the other existing CoCo audio designs, including CoCoPSG.
> > 
> > A good option for using this cartridge might be as an HDB-DOS ROM
> > cartridge for using Drivewire. A small modification will need to be
> > made to the PCB to enable use with "DOS-style" ROMs, which I will
> > be happy to document. Such usage might be especially attractive
> > to software developers, since that would allow access to DSK image
> > from both the CoCo and a more modern development host acting as the
> > Drivewire server.
> > 
> > There is no specific limit on the number of cards/carts/kits
> > available. However, I reserve the right to withdraw this offer at
> > any time due to exhaustion, lack of interest, any other reason,
> > or no reason at all. Notice of such withdrawal may or may _not_
> > be given publicly or in advance. YMMV... ;-)
> > 
> > Respectfully,
> > 
> > John
> > -- 
> > John W. Linville		Someday the world will need a hero, and you
> > linville at tuxdriver.com			might be all we have.  Be ready.
> > 
> > -- 
> > Coco mailing list
> > Coco at maltedmedia.com
> > https://pairlist5.pair.net/mailman/listinfo/coco
> 
> 
> -- 
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco

-- 
John W. Linville		Someday the world will need a hero, and you
linville at tuxdriver.com			might be all we have.  Be ready.


More information about the Coco mailing list