[Coco] CoCo/PC hybrid....

[jdaggett at gate.net]

Frank

EPP interface is used in configuring FPGAs. So being able to send and read data from a 
ROM cartridge should not be all too tricky. Only thing if I remember correctly EPP/ECP 
port speed in not all that fast. Still fast enough to move it from the cartridge to a virtual 
ROM in a PC. 

An interesting idea.

james

On 14 Sep 2009 at 21:44, Frank Swygert wrote:

> Okay, I never have been much of a programmer, and really done little 
> more hardware than a few kits and mods to existing hardware, but I've 
> been thinking too much!
> 
> One of you programming guys take a look at the resources on this site: 
> http://www.lvr.com/parport.htm
> I've been comparing the pin-out of a parallel port to that of the CoCo 
> expansion port. I'm almost convinced that it would be relatively cheap 
> and easy to make a small converter board that would plug into a standard 
> parallel port and take a CoCo cartridge. Might have to add a source of 
> external power, but that could be a cord that goes back into the PC case 
> and plugs into a drive connector. Hey, even move +12V out there! The 
> goal would be to use cartridges for data transfer purposes or to 
> build/use an inexpensive I/O board. Throw the cartridge compatibility 
> out and just make it a multi-purpose/experimenter's I/O board with a 
> wire-wrap header and I think it gets cheaper and easier. Limit the goal 
> to a data I/O board that could be programmed from Nitros9 or DECB and 
> forget the cartridge connector and things get easier!
> 
> The real headache I see is the 13 address lines. There would have to be 
> some kind of decoding done on the board so that only a couple lines on 
> the parallel port could be used for decoding. But then again if you 
> throw away direct cartridge compatibility and use it strictly for data 
> I/O, is that much address decoding really necessary? Told you I wasn't 
> much of a programmer/hardware builder!! 
> 
> Programming the port from DECB is my main interest. One thing I always 
> liked most about the CoCo was the easy I/O projects and using it as a 
> controller. Started to write a digital dash for my car using just the 
> serial, cassette, and joystick ports for inputs (mainly the relay on the 
> cassette port). Lack of an inexpensive display easy to install in the 
> dash stopped me! There are such animals for cars now, but that 
> programmable I/O port would sure make a CoCo emulator customized and 
> installed in flash memory on a simple single board computer (maybe an 
> inexpensive Mini ITX with a VIA 800MHz chip...) a real possibility. The 
> older Mini ITX boards are starting to show up on e-bay priced reall 
> nicely. Would make a good base for a "CoCo4" (didn't want to use that in 
> the subject line though!!). Use a IDE to flash card adapter for the main 
> drive, then attach a small IDE laptop drive....
> 
> -- 
> Frank Swygert
> Publisher, "American Motors Cars" 
> Magazine (AMC)
> For all AMC enthusiasts
> http://farna.home.att.net/AMC.html
> (free download available!)
> 
> 
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