[Coco] Got a DUMB QUESTION???

[Gene Heskett]

On Saturday 29 June 2019 07:46:17 Alex Evans wrote:

> Pretty sure the 4-in-1 was marketed as SCSI (and I know I used a SCI
> hard drive on it). As for the parallel port, I never had any trouble
> using it on a CoCo 3, but my printer was of the same vintage as the
> 4-in-1.

I had a dmp-130, about a year newer than the coco3, it, a cgp220 and a 
dmp-110 were all unusable on the parport. Just for giggles I opened up 
the dmp-130 and found a huge mass of filtering that slowed the signals 
to the point of never reaching a stable value until it stopped. At the 
input to the dmp-130's electronics, most logic ones never got above 2.1 
volts. I looked that connector over and came to the conclusion I'd have 
to replace it with a straight thru model, but wasn't able to find one in 
the digi-key catalog that fit.  Since the printhead itself was nearly 
shot, I retired it to the trash trailer, and bought a zerox 1650-ro for 
25 bucks at the next Jacksons Mill hamfest. Serial, daisy wheel, 40 cps, 
fastest daisy ever made.  And if I could get fresh ribbons for it, it 
would still be working today. But the ribbons available today have been 
in a hot Mexican  warehouse for 25 years and break like glass with the 
first hammer strike.

About that time drivewire arrived, and I setup a couple bash scripts to 
take in the printer files, run them thru cups, and feed them back to a 
brother HL2140, a 110 dollar B&W laser that can do 19 PPM, and its still 
sitting here working just fine after 25 or more reams of paper, on its 
4th toner replacement.  The smaller printer of 2, I also have a color 
inkjet brother that can scan and print 11x17 tabloid with enough monkey 
business feeding the big paper by hand.  Thats a right PITA though, so I 
only use it at that size for rockhopper output. Rockhopper is a running 
LinuxCNC scanner, drawing one a logic diagram of how a machine is 
running, but it takes at least 2/3rds of a sheet of 1/4 plywood to paste 
it all together once printed.  Not done every day for obvious reasons 
but very handy for troubleshooting.  So of coarse when one has found the 
problem in the .hal file and fixed it, all that paper scotch taped and 
stuck on the plywood is obsolete. But it served its purpose anyway.


> On Sat, Jun 29, 2019 at 3:50 AM Gene Heskett <gheskett at shentel.net> 
wrote:
> > On Saturday 29 June 2019 03:07:16 Gene Heskett wrote:
> > > On Saturday 29 June 2019 01:36:04 L. Curtis Boyle wrote:
> > > > It does NOT require an MPI. It even has a Mini Bus connector
> > > > inside of it, that Disto sold multiple cards for (the maximum
> > > > functionality was the 4 in 1 board, which added a hardware
> > > > serial port, parallel port, SASI hard drive interface, and a
> > > > real time clock, if I remember correctly).
> > >
> > > Thats close, but without the mpi, it (the 4n1 version) will need a
> > > 12 volt wall wart plugged into a jack in its edge as the serial
> > > port can't get it from the coco3. I never bothered with it as I've
> > > an mpi, which can supply that voltage.
> >
> > I should add that on a coco3, because its double clock speed, pretty
> > well renders the parport worthless unless one wants to design a
> > buffer which will hold the data true long enough for it to get thru
> > the FCC mandated input filtering in most printers parallel inputs,
> > which need valid data and strobe timings in the 2  microsecond
> > territory. At the coco3 clock speeds you will miss characters about
> > 20% of the time. I don't think that FCC rule existed at the time
> > Tony designed the 4n1. Since the Canadian DOC usually followed the
> > US in things like that, but with a few months delay, Tony didn't try
> > to please with that design.
> >
> > What may have worked but I never got around to trying it, might have
> > been to halt the cpu when the strobe went true with the e-clock, and
> > cancel the halt with the printers ack. But I didn't follow up and
> > see how that would have affected os9. I don't believe any of the
> > halts would have affected dram refresh long enough to matter.
> >
> > > > L. Curtis Boyle
> > > > curtisboyle at sasktel.net
> > > >
> > > > > On Jun 28, 2019, at 11:13 PM, Joe Schutts via Coco
> > > > > <coco at maltedmedia.com> wrote:
> > > > >
> > > > > Hi Everyone,
> > > > > I (THINK - BUT I'M NOT SURE YET - BUT I'M HOPING) that I just
> > > > > bought a Disto II Super Controller for the CoCo (on E-Bay -
> > > > > sorry guys)... My question is, WILL THIS CONTROLLER work on a
> > > > > CoCo III WITHOUT an MPI Interface OR does it require it???
> > > > >
> > > > > Thanks guys...
> > > > >
> > > > >
> > > > > --
> > > > > Coco mailing list
> > > > > Coco at maltedmedia.com
> > > > > https://pairlist5.pair.net/mailman/listinfo/coco
> > >
> > > 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>
> >
> > 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>
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > https://pairlist5.pair.net/mailman/listinfo/coco


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>