[Coco] CoCo4! 50% done!

[Aaron Wolfe]

A few minor corrections:

The current CoCo3FPGA does include some enhancements beyond a stock
Coco 3.  There are new graphics modes including higher color modes
(256, 1024 or 4096? its been a while).  There is on board storage for
ROMs and mechanisms for switching between them, and there is the
"Becker port", a very high speed serial interface.   There is part of
a fd500 floppy controller: to the CoCo it looks like a regular FDC but
behind the scenes it speaks DriveWire.  I believe there is also an
orchestra 90 card built in.

Gary Becker did design I/O boards that included coco compatible
connections for joysticks, a bitbanger serial port, additional ram,
probably other stuff I'm forgetting.   It is pretty neat connecting an
old RS joystick to a modern FPGA board and playing a game.  I think
these were proof of concept, not something intended to be made in
large numbers.

One thing CoCo3FPGA does not have (unless it was added and I missed
it) is support for the SD card.  As I recall, Gary said it would be
possible to add direct r/w capabilities so that an OS9 driver could
access it (if that driver was written) but that there really wasn't
space in the FPGA for doing anything in DECB.  I very well could be
out of date or just wrong on that though.

Like I mentioned before, I think the project on the DE1 is more of a
stepping stone than a destination.  The FPGA is just barely big enough
and prevents some future things from being implemented, its not in a
consumer friendly case, and the process to set it up etc is not plug
in play.  In some ways the hardware to make the most of Gary's work on
the software side doesn't quite exist yet.



On Tue, Feb 4, 2014 at 1:10 PM, Frank Swygert <farna at att.net> wrote:

> So why hasn't everyone went out and bought one? Well, it's not everyone's
> idea of a CoCo4. It's faster, but has no extra features -- no better
> graphics or anything like that. You can't use old peripherals like disc
> drives with it. Storage is strictly on SD card, with software emulation of
> the disc controller (I might be mistaken here...). No, I don't have one.
> Personally I don't see a problem with a new compatible machine not having
> disc drives or being able to connect to the old peripherals. They are all
> old and antiquated now. It's hard to find a 360K 5.25" drive, and when you
> do it may not work. I understand the guys wanting one for nostalgia, and
> some have a legitimate need to transfer old floppies to the newer media. The
> former should probably stick to the old hardware, the later can find most
> software on the internet already in .dsk files. If they have old floppies
> with files they really need then use drivewire on a real CoCo and transfer
> them, or find someone who will do it for you. I don't think the DE1 has been
> set up to accept any kind of joystick, but I think it can be done. I
> wouldn't try making an interface for the old CoCo sticks, but something
> currently available that will work in a similar fashion. The original stuff
> should be relegated to those retro users who want/need it, it's getting old
> and worn now.
>
> That said, the DE1 is just a super fast CoCo3. that could be considered a
> CoCo4 for all practical purposes. But is it enough? Not enough for a lot of
> people to get one, apparently. I'd like to see some upgrades as far as
> graphics and such, but Tandy hobbled the CoCo3 with the design of the GIME.
> I don't think losing CoCo1/2 software compatibility (say losing the
> semi-graphics modes altogether -- I know the CC3 lost some of them anyway)
> would be an issue, but it needs to keep CoCo3 specific compatibility.
> Keeping that and having higher resolution graphics in the same machine is a
> challenge to say the least. I'd like to boot the machine then run either CC3
> or "CC4" programs without rebooting, but that may not be possible. I suppose
> it would be okay to reboot when switching between the two. Most OS-9 games
> required rebooting anyway, so it wold just be like going from DECB to OS-9.
> But a standard for the new graphics and any other capabilities would have to
> be set. That is the bi
> ggest issue right now. No one has come up with anything! If someone took a
> DE1 with the CoCo3 core and came up with a working higher res graphics
> solution that could be loaded into the FPGA and would work in CC3 and CC4
> modes without reprogramming the FPGA it would quickly become the standard.
>
> Others have different ideas -- I'm just trying to be practical. Too many
> different ideas, and no one actually doing anything -- that is until the CC3
> FPGA came out. That was mainly one person's doing -- now someone needs to
> take the next step and make some enhancements and keep CC3 compatibility...
> This may require a bigger FPGA, which would mean substantially more cost...
> until now. Terasic now makes a DE1-SoC board with a bigger FPGA and more
> processing power. It would probably require re-writing the CC3 core, but it
> isn't much more than the original DE1 board ($199 vs. $150). I don't know
> much about it, but the layout is very similar to the DE1.
> http://www.terasic.com.tw/cgi-bin/page/archive.pl?Language=English&CategoryNo=167&No=836
>
> These are meant to be evaluation boards, but the CoCo community is small
> enough that they would be a great relatively low cost base to use.
>
> Some, myself included, have encouraged using something like a Raspberry Pi
> or Mini ITX board and "build" the "CoCo4" mainly in software. The hardware
> has the power to run a "ghost" emulator and for all practical purposes look
> and feel like a modern CoCo. Some say they like the "look and feel" of the
> original. Well, the "next" version of anything usually uses available
> technology and loses some of the old look and feel, and many upgraded their
> CoCos with PC keyboards anyway, so why not use one on an advanced CoCo? I
> say "ghost" emulator because I think it (and the host OS) should strictly be
> in the background. If the host OS is totally inaccessible that would be fine
> by me, but it would probably be best to have a hot key that would allow at
> least limited access for maintenance and some tasks the emulator may not be
> capable of.
>
> I wonder what this will end up selling for?
> http://www.fpgaarcade.com/?q=node/6
> It has all the needed connectors, and there are cores for several 8 and 16
> bit machines (Amiga, Atari ST, VIC20, etc.). A CoCo3 (4) should be doable...
> The "expansion ports for external controllers" look like floppy drive ports,
> but probably aren't...
>
>
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco