[Coco] Smart IO interfacing on the CoCo

[Gene Heskett]

On Saturday 25 April 2020 13:55:55 RETRO Innovations wrote:

> On 4/25/2020 12:35 PM, Gene Heskett wrote:
> > The real question, Jim, is: If you proto a design and it works well,
> > will it still be available a year from now for a 3rd run of 50? 
> > Lots of this stuff gets replaced by newer, glossier versions
> > everytime you load the washing machine with last weeks underwear. 
> > We have, or did have, 5 year laws, but they seem to be routinely
> > ignored.  Have they been sunsetted? IDK.
>
> I think your comment is more directed to Allen, but I will say that I
> designed a unit with an AVR8 based ATMEGA1281 in 2004 and I am still
> able to source those parts new from Microchip (who bought Atmel a few
> years back) without a "Last Time Buy" commitment.  I think PIC has
> been reasonably good as well, at least for the PIC14/16/18 line, not
> sure about the 24/32 lines. That said, I've had to redesign the same
> unit because it's a CoCoSDC-like drive for another platform, and 3M
> (who made the SD connector) EOLed it.  At that point, I looked at all
> the suppliers and noticed many of them designed a specific variation
> of SD card connector (it has a half moon indent in the top metal), so
> I redesigned with that part in mind.  Finding those has been much
> easier (and cheaper). So, I agree parts EOL is a major concern.
>
> My main concern with such USB projects is the cost.  As a general
> rule, I set sale prices as 3X COGS (cost of goods sold) which is
> pretty standard.  I lump in PCBA service costs, shipping, parts, PCB
> manufacturing, taxes, etc.  If a part costs $10.00 to source, that
> immediately means the sale price of the finished product will be
> $30.00.  Then, I think about the value of that as a potential buyer.
> $30.00 for just the module is tough to swallow.
>
> Mind you, I know USB support is possible (Paul Fiscarelli's done it, I
> think Mark Marlette had USB going, I remember seeing some project at a
> recent CoCoFEST! doing USB, etc.), so I wouldn't pooh pooh the
> possibility of it, just the economics.  I actually chose the PIC 24MX
> line because it also offers USB host mode and is very cheap ($2.00 or
> something at the @100 unit quantities I order), but I've not got the
> project moved along in light of other fun things.

$30? I'd buy it. Look at that in todays dollars Jim, I think its 
reasonable and I've been on SS for nearly 20 years.  I have 4x that in 
usb cables and hubs just hooking up drivewire to this machine. Drivewire 
doesn't care as long as the serial to usb adapter isn't a prolific, but 
FTDI stuff Just Works. The hub is basically a power supply and at one 
point I had a cheap B&W laser printer on the coco's desk which /p 
actually drove the drivewire, drivewire handed it off to cups, cups then 
drove that printer on the cocos desk. Clear crisp text at 19 pages a 
minute, but that printer has now died. But at $120 a decade back, its 
printed probably 35 reams of paper on 3 toners so I don't figure it owes 
me a thing.  I need to get a new one when this covid thing has blown 
over.

Works well except for the apparently un-mitigatable conversion error from 
the coco's cr's to linux lf's in minicom, there doesn't seem to be 
xmode, or minicom settings that make it 100% compatible, so the up-arrow 
key to repeat the last command actually resets the connection at the 
coco3 end. Like hanging up and logging in anew.

Logitech now has keyboards and mice that use the same button, but I'd 
imagine that would be a whole new driver, but it would be neat to have 
both on the coco. Be aware the pairing only works with that mouse, and 
mine died so I am back to two buttons in this lashup. NBD. I have a 
serial mouse on the coco already. But its a roller ball, going on 30 
years old now.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>