[Coco] Seeking ECB Rom in the US

[Kip Koon]

Bill,
You are correct.  Although I did not mention it to Sean, I was thinking
about getting the needed A14 address line off the motherboard for pin 27 of
the 27256 which is a 28 pin device and will fit into the 28 pin socket on
Sean's Coco 2B motherboard. On the 27128, pin 27 is the PGM/ "PGM Not"
signal which of course is not needed to use the eprom in the coco 2B.  If it
is not connected to anything you could just connect 27 to a pin with A14
directly.  However, if they did connect pin 27, then the trace will have to
be cut first before connecting pin 27 to A14 somewhere.  I'd have to see the
schematic for the Korean Coco 2B before I could say.  By any chance, A14
wouldn't already be connected to pin 27, would it?
Otherwise Sean, I'd need to burn an extra eprom for you.  If so, please let
me know what type of socket the cart has for the disk controller.  
Kip

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
Behalf Of Bill Pierce
Sent: Friday, January 25, 2013 8:38 PM
To: coco at maltedmedia.com
Subject: Re: [Coco] Seeking ECB Rom in the US


Kip,
Again... You are replacing the DISK rom in the emulator, not the BASIC rom.
It is residing in the emulated cartridge port and not in the mother board
roms. If you were putting HDBDOS on the motherboard rom, ECB would not be
present and HDBDOS would be in the wrong location at $A000. HDBDOS is an
enhanced DECB rom and has NO code for CB or ECB. The notice you see in the
bootup shows that it is DISK EXTENDED COLOR BASIC, just like the rom in a
Tandy disk controller. If you are accomplishing this on the motherboard, I
would like to know how, as well as where you got the roms.

If you burn HDBDOS on the same rom as CB & ECB, it will not work. Unlesss
(AFAIK) you physically modify the addressing on the Coco which I think would
not be an easy task.
Again, as far as I know, the HDBDOS rom must be in the catridge port on a
disk controller or rom cart. If you are loading it from disk, it is still
being loaded to the cart area. In this case, it is loaded into low memory as
an ML program then a rom/ram program is run copying roms to ram and hdbdos
is copied to $C000, the cart area and the executing it, therefore patching
it into CB &ECB.

Bill P

Music from the Tandy/Radio Shack Color Computer 2 & 3
https://sites.google.com/site/dabarnstudio/
Bill Pierce
ooogalapasooo at aol.com




-----Original Message-----
From: Kip Koon <computerdoc at sc.rr.com>
To: 'CoCoList for Color Computer Enthusiasts' <coco at maltedmedia.com>
Sent: Fri, Jan 25, 2013 7:11 pm
Subject: Re: [Coco] Seeking ECB Rom in the US


Bill,
I have the coco2dw3.rom image file booting Return of Coco just fine.  It has
the standard Coco 2 boot message as you can see below along with HDBDOS v1.1
DW3 Coco 2 message as well.  
DISK EXTENDED COLOR BASIC 1.1
COPYRIGHT (C) 1982 BY TANDY
UNDER LICENSE BY MICROSOFT

HDBDOS 1.1D DW3 COCO 2
Yes, the HDBDOS DW3 Disk Basic rom image must be at $C000 and that is
exactly where it is in the rom image.  It is pretty cool.  I'm thinking of
installing a copy in my Coco 2 in one large 27256 eprom.  I need to replace
the HDBDOS DW3 Disk Basic portion of the rom with the current HDBDOS v1.4
DW3 Coco 2 rom image though.  
Anybody have an adapter they already designed that solders in place of the
soldered in rom.  How about just desoldering the Chip Select pin and
logically deselect it so it does not turn on, or better yet have a switch
somewhere to switch between the built in rom and the add-on eprom?  That way
I could use it the standard way or the HDBDOS v1.4 DW3 Coco2 way.  Since I
have external disk controllers, I could just leave it as is and put HDBDOS
v1.4 DW3 Coco 2 rom image into an 8k eprom and install In one of those.  Not
sure yet how I want to did it.  I also have to think about my coco 3 setup
as well.  What do you all think?

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
Behalf Of Bill Pierce
Sent: Friday, January 25, 2013 12:23 PM
To: coco at maltedmedia.com
Subject: Re: [Coco] Seeking ECB Rom in the US


Kip & Sean,
I'm not sure, (I know I'll be corrected if I'm wrong), but you cannot put
the HDBDOS rom in the Coco ROM space with the CB & ECB. It goes in the Disk
controller or a rompak. The HDBDOS rom is hard coded for the Disk rom area
(it is a replacement disk rom) and would not work if mapped to the CB/ECB
area. Unless there's a way to map it higher to $C000 this idea will not
function. CB & ECB map to $$8000 & $A000. You may know more about the
mapping than I do as I'm just going on what I've gathered from others. I'm
no techie.

Bill P

Music from the Tandy/Radio Shack Color Computer 2 & 3
https://sites.google.com/site/dabarnstudio/
Bill Pierce
ooogalapasooo at aol.com




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