[Coco] Chuck's computer design...

[Frank Swygert]

I have a couple suggestions (not that you want/need any...).
 
1) Get rid of the CoCo type slot! I would suggest something simple and available, like a double row header connector. Then you can have a CoCo slot adapter if needed/wanted. Using a double row connector you could even add some lines -- the CoCo adapter just doesn't use the extras. 

2) Why not use that core someone posted about earlier? That would use a standard keyboard and monitor. IMHO it should be modified to use a memory card or USB stick drive in place of the floppy(s). Something like floppy emulation on a hard drive (HGB-DOS?) could be used if DECB compatible. If it's strictly for Nitros-9 it would emulate a hard drive only. It just needs to be written in such a way that the card can be plugged into a PC. 

You could have a "speed selector" (would be nice in hardware, but software will do) up to 20 MHz. Would need to be slowed down for CoCo OS-9 games and such, but if this is mainly to be a new "hacker" computer, it doesn't have to be graphics compatible. The main board can have video and such and you could have an eprom only controller or "target" board without things like a full keyboard and video. Of course it may be that the main board cost is low enough that it's not worth making two -- one with everything might just keep volume up and be more economical. Of course one board prepped for everything doesn't mean everything has to be installed on the board... 

I can see a need for something more powerful and easier to use than something like the PIC and STAMP series of micro controllers. It's too hard and expensive to play with a full blown PC, and most controller boards with a lot of power are rather costly. 

Personally I'd like to see a board that had something simple to use like DECB on it, with some enhancements (at least enhanced to ADOS standards!). DECB isn't real powerful, but it was very easy to work with. A 5+ MHz machine running DECB would be very powerful compared to a 2 MHz CoCo3! Wouldn't even have to be 100% compatible with DECB -- if it had 80% compatibility code would be easy enough to modify to work. 

I had a digital dash (for a car) all but working from a CoCo3 once. I used the joystick ports to read resistance and the cassette port (I think...) to read pulses for a speedometer. Didn't have a tach worked in there yet, was looking for the basics first. Nothing graphic either, just a text display with labels and numbers. I wasn't good at graphics, decided I would make do with different size numbers (large in center for speed, smaller in corners for others). What killed the whole idea was an adequate display at the time -- LCDs were expensive, and I needed an NTSC model. Now they are relatively cheap!! Wish I'd kept that code... another problem, of course, was the size of a CoCo board. I could have worked around that though... 


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Date: Sun, 14 Sep 2008 22:30:09 -0400
From: Chuck Youse <cyouse at serialtechnologies.com>
Subject: Re: [Coco] OT: ummmm... OS-9 computer system pictures for
	your	viewing pleasu...

I've got plans on the drawing board for a GIMIX-like ATX motherboard,
2MHz 6809 etc., DAT, 2MB RAM, 8-slot backplane.  That's really what all
these cards I designed are ultimately for; I purposely designed them to
work in both systems.

Just gotta get this first round of production boards out the door,
hopefully some folks'll buy 'em to fund the bigger project.

-- 
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)