[Coco] Re: What it is, and Hi-Res Interface Musings - was RE: What's this?

Andrew keeper63 at cox.net
Sun Aug 27 19:00:07 EDT 2006

Thought I would post my own reply on this...

Like everyone else said, it is a high-resolution joystick interface 
adaptor, which plugs into the cassette and joystick port, then a single 
joystick plugs into the other end, etc (like everyone else said).

There was a small review of it in the October 1987 issue of the Rainbow 
(page 130) - it originally sold for $9.95. In the February 1988 issue of 
the Rainbow, there is an article by Duane M. Perkins called "Programming 
for the Hi-Res Joystick Interface" (page 122), which presents both the 
machine language code and a BASIC program which POKEs it in and uses it 
in a simple manner.

I don't know if these devices are rare or not - probably about equal 
with other CoCo equipment, maybe a little more rare as there wasn't much 
Radio Shack software that took advantage of it. Most software that did 
was made by third parties (such as CoCo Max III). Interestingly, there 
are also other Hi-Res interface adaptors, which came out after the Tandy 

One of them was "made" and sold by HAWKSoft. I put "made" in quotes 
because I have it here in front of me, and one side of the case has 
"TANDY" on it, and on the other side is a printed label for HAWKSoft, 
reading "HAWKSoft Dual Hi-Res Joystick Adapter" - underneath the label, 
the original Radio Shack label is visible.

On one end is the two cables to plug into the joystick and cassette 
ports. On the other end is the port to plug in the joystick or mouse 
(indeed, using one of these with the dual-button mouse is a dream). Here 
is where it gets interesting, and is likely why it is "rebadged" by 
HAWKSoft: On one side of the adaptor is a 4-pin DIN plug - I don't have 
my manual to this adaptor handy, so I don't know what this is for. On 
the side where the cables are, are three switchs. One, in the middle of 
the case (between the cables) is a simple slide switch - this may be a 
standard switch (ie, found on the RS adaptor as well), or it may have 
been added. The other two switches are round lever toggles, which do not 
appear on the standard RS adaptor. If I remember correctly, the toggles 
are for using it with different programs, and the slide switch is for 
bypassing the interface. Ultimately, it looks like this adaptor is a 
modified version of the standard Tandy interface.

I just rummaged thru my boxes of stuff, seeing if I could find the 
manual, and all I could come up with was some hand written notes I had 
made myself. I tend to wonder if it came with a manual at all. I have 
never thrown away any of my CoCo stuff, and I found many other manuals 
from the same time period (15-20 years ago), like my CM-8 manual and 
many others. Anyhow, I figure that if there was a manual, why would I 
have hand written notes? Anyhow, my scrawled notes read that if you have 
both toggle up, it is for "ColorWare (CoCo Max)", both down is Low-Res. 
If the "left" one is up and the "right" one is down (looking toward the 
switches, TANDY logo UP and HAWKSoft label down), then that is the 
"Tandy" mode. No idea what the opposite is for (if anything). Also, the 
port on the side is a passthru port for the cassette interface, and the 
slide switch is an enable/disable for the adaptor - on is to the right, 
so when the switch is in this position, the adaptor is usable, otherwise 
the cassette interface is used.

Something I wonder about is whether the other position might be for 
Diecom's Rat Graphic Design package? I know that package used its own 
custom mouse and/or dongle as a copy protection measure - does anybody 
have this package? Does anybody know if this package is available for 
download somewhere (since Dave Dies let us know all of Diecom's stuff is 
PD, a download should be legal)?

Also, some other things I was pondering on about the joysticks and 
high-res interfaces for the CoCo: Number one, does anybody know if it is 
possible to hook up a standard two-button serial mouse to the bit-banger 
serial port or RS-232 pak? In theory, the RS-232 pak should almost be a 
"no-brainer", since it is a standard RS-232 port - you would just need 
to program a driver to read the port and interpret the results - but 
what about the bit-banger port? Has anybody done this?

Secondly, has anybody ever tried to "increase" the resolution of the 
standard joystick port in software? What I mean by this is by using 
"dynamic scaling", similar to mouse acceleration used by PCs (I think). 
Basically, you read the values from the joystick port (0-63 on both 
axes), and you compare "this value" with the "next value", and adjust 
the scalar value to multiply by based on the difference. Thus, if you 
move the mouse quickly while reading the port, the differences in 
successive reads will be large, so you multiply by a larger value (up to 
15), if the differences are small, you multiply by small amounts (down 
to 1). Maybe you could also use the differences just to note and tell 
"where/which way" the joystick is being moved, and adjust in that manner 
(some form of predictive read-ahead positioning algo?), also taking into 
account the differences and multiplying properly as above.

Another idea I was thinking about was the possibility of hooking up a 
standard PC or Nintendo game-pad (albeit with a ton of hacking on the 
internals) to the CoCo. Even a simple Atari joystick could be fun. 
Another idea would be to somehow build an interface adaptor for a 
standard serial mouse to the joystick interface...

-- Andrew L. Ayers
    Glendale (Phoenix), Arizona

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