Subject:
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Re: HB Downloader Trouble
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Mon, 13 Jan 1997 20:42:53 GMT
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Original-From:
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Fred G. Martin <fredm@media+AntiSpam+.mit.edu>
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Viewed:
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1561 times
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Success on the first bootstrap download and failure to write into RAM
could easily be explained by a fault in the memory circuit. The
memory circuit, which includes the 'hc373, the 'hc132, and the RAM
chip itself, with about 27 signals going to the 'hc11, is by far the
most complicated subsystem on the board, and any single problem
anywhere in the circuit will cause the memory to not work, leading to
the download error described.
It's tedious, but the way to debug this is to individually examine the
signals on the '373 and the ram chip using a scope or logic probe.
With the HB turned on (not in bootstrap mode -- just turn it on and
let it execute garbage), all of the appropriate signals (data bus,
address bus, R/W line, '373 clock line) should be oscillating. If any
are disconnected or shorted to power or ground it should be easy to
see with the logic probe.
Then with an ohmmeter and the board turned off, check that there is
continuity where there is supposed to be (using the schematic as a
reference) and no shorts between address and data lines.
If you've got a spare memory chip and/or 'hc132 lying around, it's
easy enough to pop in replacements, but in my experience a bad chip is
rarely the problem; it's almost always bad wiring.
-Fred
In your message you said:
> On Fri, 10 Jan 1997, Bill Rose wrote:
> > having great difficulty downloading my board. Here are the messages I am
> > getting when I attempt to use the dlm software from the software web page.
> > I followed the args "dlm pcode_hb.s19 -port com1 -256". The boot loader
> > gets done, the board synchronizes ok and then when sending the pcode_hb.s19
> > at 9600 baud I get the error "Board memory error: wanted 00, got 3e at
> > address 8000 and it continues to give different board memory errors. Can
>
> I too have this problem. I originally thought it was the RS232
> converted, but I have since replaced this part and still get the
> downloading error (using HBDL and DLM). I can't find any physical
> defects with the board (solder bridges, cold joints, etc). I am not
> sure how to proceed, but am willing to replace the memory chip (since I
> happen to have a spare). However, at this point and with this additional
> account of the same problem, I'm willing to suspect the downloader and/or
> the pcode_hb.s19 or the cables or the port settings.
>
>
> Karl R Altenburg altenbur@plains.NoDak.edu
> North Dakota State University, Fargo, ND 58105
>
> All things are artificial, for nature is the art of God. SIR THOMAS BROWNE
>
>
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Message has 1 Reply:
 | | Re: HB Downloader Trouble
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| Well, I got my HB working. I brought it over to a friends house where he was able to program it using his machine with little trouble. So, obviously it was not the HB per se. I brought it back home, and had trouble downloading from IC 3.1b but was (...) (28 years ago, 14-Jan-97, to lugnet.robotics.handyboard)
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Message is in Reply To:
| | Re: HB Downloader Trouble
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| (...) I too have this problem. I originally thought it was the RS232 converted, but I have since replaced this part and still get the downloading error (using HBDL and DLM). I can't find any physical defects with the board (solder bridges, cold (...) (28 years ago, 13-Jan-97, to lugnet.robotics.handyboard)
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