[Coco] using /ddr0 as default (not boot) drive

[Vanderberg Family]

>> >Yeah, I'm a tinkerer and maybe a JOAT even. I've been chasing electrons
>> >for a living for 62 of my 76 years. Funny thing though, that, and a
>> >buck 35, will get you a 16 oz coffee to go at 7/11. ;-)
>> 
>> Yes, but as a hobby, how can it be beat?
>
>I have rather eclectic interests.  In addition to the coco, I have an 
>amateur sized metal lathe, a wood lathe, and an HF micromill that isn't so 
>micro anymore, cnc controlled by emc.  And of course the usual collection 
>of woodworking tools, and have 11 pieces of furniture either done or under 
>construction.
>
>You can see some of what keeps me out of the bars in my dotage at 
><http://gene.homelinux.net:85/gene>
>That is actually this machine. :)
>
>> In fact I started up my CoCo
>> again for a few years in the late 1990's but just as in the 1980's life
>> and a family conspired ... well, we won't go there.  A few years ago I
>> suddenly had excess time and  could follow through with my hobby:
>> robotics.  Due to a severly limited budget I couldn't get startup with
>> arduino or propellor or some of the more well known micros, but I
>> discovered Picaxes (PIC based, embedded basic,  free IDE, serial comms
>> for programming, amazing I/O ports, i2c etc. - no, not a stockhloder or
>> employee - just a fan as I am of the CoCo - something about solving
>> problems with minimal hardware & Unix's appeals to me) and with a ten
>> dollar bill I was reading inputs and writing outputs just like in the
>> old days on $100 million Westinghouse DCS systems controlling boilers &
>> turbine generators and solar fields.  I couldn't believe it.  I
>> developed a "radar" style system that mapped the area with IR distance
>> sensor on a ser vo that displayed on the PC and saved the data via i2c
>> to eeprom.  That data was accessed by another Picaxe ((representing
>> another robot) and expected it to navigate the maze totally blind based
>> on the data received from the first robot.  The obvious flaw here is
>> the stupid cable - really limits a robot :)  Someday I would like to
>> get a wireless chips and get back to it but it was only ever a proof of
>> concept project because I wanted to see how far I could take it. 
>> Suddenly I wondered why I was displaying on the PC using serial comms
>> when I could do it with my CoCo (sort of an excuse to do some fun
>> unpacking).  I plan to use the CoCo as the display (20x4 lcd screen is
>> rather limiting) and to provide disk drive capabilities along with
>> floating point math.  Oh, I could already do all of that on a PC, but
>> where is the fun in that?  Also, it would be trivial to add the CoCo to
>> my Picaxe network (currently 4 configured as a DCS network but for a
>> few less $$) and get RTC input fo r CoCo as well as any sensor input or
>> control output I want to add to CoCo.  I have thought about designing
>> an interface to multipak but that bitbanger port just seems tailor made
>> for Picaxe serial comms.
>> 
>How fast is this picaxe?  Can it drive step & dir drives through a parport 
>at 50 kilohertz?

Easily.  I have seen quite a few posts about doing this on the Picaxe forum.  In fact I started up my Picaxe IDE/simulator and used the pwm wizard to test.  Even using the oldest slowest (4/8Mhz 08/08M - cheapest - one pwm port) version gave me the correct PWMOUT command parameters to give 50khz pwm out.  I tried this one because I see so many posts about controlling steppers with 3 08's and you can get 3 of them for $5.  Then I tried the newest (8/64Mhz 28/40x2 - maybe $14 - 4 pwm ports) and once again got a correct answer.  You should see the params it spits out for 50khz pmout on an x2 part at 64Mhz - the param includes a div factor I've never seen before.  They had to do some division to get down to 50khz pwmout while running @ 64Mhz.  In fact, in the manual there are numerous illustrated examples of how to hookup common sensor inputs, contol outputs and Picaxe to Picaxe comms.  Both types of stepper motors, servos and direct motors are included.

So, all versions should work, the choice would be regarding the number of inputs/outputs you would need in addition to the motors (many posts about feedback - not sure if that is required in your case but I would think so or at least beneficial) and a decision about how much program and internal data data space you need.  What I normally see is a larger Picaxe controlling several smaller dedicated ones.

I am not trying to sell you or anyone else on Picaxes.  For me it is a no brainer.  I have no budget so I will never be able to pay for the setup to start with arduino or propellor or PIC or whatever.  But for the Picaxe, you use your PC with free downloadable IDE/simulator (even a flowcharter that builds your program - not my style).  You write your program on PC then download to Picaxe with your standard serial cable or USB->serial cable (or across internet or wireless - these guys are worse than the CoCo group about using their "favorite chip" to do what the big boys do with $$$ and development labs).  The chip requires 3 resistors for a downlad circuit and and one resistor to ground the reset and that is all.  And includes standard comm protocos for serial, i2c, spi, one-wire (even saw someone interfacing to CANBUS) for easy Picaxe to Picaxe comms and comms to the huge variety of i2c, et.al. chips to add or control virtually anything (RTC, EEPROM, I/O, additional protocols, wireless, you name it).

Based on the PIC which is certainly fast, this is not the fastest (embedded basic interp takes a toll) and of course some of the memory is used by to contain the firmware.  It is not the most feature rich micro out there (but the cost of those darlings...) but they keep adding stuff - investigating on-board usb now which will open up vast worlds although I think it will turn out that full usb control eats up too much chip and dedicated usb controller will be required as is the case with PC - it is in the usb cable.  But it works well, has everything I need (or I add a chip for example if I needed parallel), no equip needed to program and you cannot beat the turnaround for program mods - just d/l and try your mod - no pulling the chip cause there is no equip or burner required).

If you think this might meet your needs, I suggest that you do 2 things.  Vist the forum @ www.picaxeforum.co.uk and try a search or just ask.  That forum is absolutely the most polite, helpful and KNOWLEDGABLE I have ever been part of.  I think that is partly because Revolutin Education (Rev-Ed) created the Picaxe line primarily to service the British educational system and therefore you get a lot of posts from those attending school (far more posts are from oldsters like me or professionals with a hobby).  It is a great idea. in a standard computer class in Britain (& Aussies and Kiwis) you can work on a Picaxe from a very early age (And now we know why they keep the price so low - teacher has to budget one or more pc's for the group and a Picaxe plus some resistors, caps, led's, switches, etc for each kid).  Within moments the kid is blinkin led's, running toy motors, flipping swithes and THEY wrote the program themselves and can take it home and make mods at home on PC using the simulator to test (therby wowing the parents and siblings).  Next morning, load the floppy in the pc, download and amaze their friends with what their project can do now.  Rev-Ed also wanted the Picaxe line to still be the chip those same kids use in high school and college so it is very robust in terms of choices/features.

/rant on
I wish America had the foresight that Britain has.  We don't build anymore, we mostly just provide service to the world and that will only work as long as WE are putting out the best ideas and software and let them build it.  But what are we teaching our kids?  To be confident and pretty (regardless the surgury and chemicals that takes) and to excell on FaceBook and try to get something to go viral on the internet.  I am seeing a lot of posts by UK college students doing very sophisticated things with the Picaxe, and why not?  They have been learing on the same line of chips through their entire school career.  Britain is going to harvest a rich crop of engineers, programmers and technicians.  Personally I feel that playing with chips and programming and logic helps everyone regardless of their course of study or eventual career.
/rant off

I tried a search last night and got pages of posts from many people re: stepper control and quite a few specific to CNC.  One hint, the forum search discards 3 letter words due to commonality.  So, if you type in CNC, add asterisk ie. CNC* and it will use that search term correctly.

The second thing I suggest is to got to www.rev-ed.co.uk/picaxe and download the ide and try it out.  It includes the manuals and sample projects and details on features sets of each chip.  And has a very structured and feature rich basic.  I would be interested to hear your results.

Now, to bring this back to THIS list, are you anticipating a role for the CoCo in this?  I don't have any idea of the requiremens for a CNC program so I don't know what computer you would use for the interface and upper level control and patterns.  But as for controlling the actual hardware, yes I think the Picaxe would be suitable (and not much of a drain on the pocket if you end up going another way).  Check out the CNC* and stepper control posts, though.  This project IS being done.  Perhaps your input is what someone else trying this project on their own needs.

It is kind of funny.  Due to poor quality dialup out here in the desert I avoid things like YouTube (sp?).  OK the main reason is that I am a social network grouch (refuse to use cell phones also so there you go).  However, I probably know as much about what is on there as anyone because it seems every day, I see a post for something "cool" somebody did on YouTube or one of the many DIY sites and he wants to know "how can I do this with a Picaxe".  And the group gets to work gives him advice and hints and even code and schematics if needed to accomplish his project.  From adding a Picaxe inside a XBox controller to give artificially high rates of gunfire for a game to using a scavenged Nokia GLED screen for high res full color display for Picaxe, even being used for email forwarding an other stuff I refuse to know about (still grouchy).  Sometimes I just scroll through the finished projects section for ideas (or to see how someone else solved my current issue).  And ask a question, get informed answers literally from around the world.  Unless of course they can tell it is for a school project (happens a lot) in which case they are very free with help to get past stumbling block but ensure the student thinks it through on his/her own to generate the right questions.

I am not really sure why I gave so much detail to such a simple question, but I have to admit I am interested and would like to follow your progress - especially if it turns out to be a marraige between CoCo and Picaxe.  
My neighbor uses a pc to control his CNC but his main project is rebuilding a WWII era jeep from the ground up for his kids when they get older.  Beautiful machine he is putting together.  So his plans to use an old apple to do the same as you is far in the future.

>> >The fact that you have a 40tSS disk to be used to populate the ramdisk
>> >makes the fixing of help and error very easy. Patch those 2 files, help
>> >and error, for starters so they look in /r0/sys.

This is the method I used (also krnP3 to get extended error messages).  Works great.  Thanks to you Boisy and Robert for the clue to success.  More detail in another post back to Robert if you care.

Ed


________________________________________
PeoplePC Online
A better way to Internet
http://www.peoplepc.com