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Per Westermark
11/12/11 05:25
Read: 621 times
Sweden


 
Msg Score: +2
 +2 Good Answer/Helpful
#184674 - What situation would that be?
Responding to: Richard Erlacher's previous message
But note that the original EPROM chips did not support electrical erase. And applying UV light meant bulk erase.

So the use of a single external EPROM would not allow the lower part of that EPROM to contain a loader handling any serial port and then have that loader receive more program to burn into upper parts of the EPROM - especially since the EPROM would not run the processor while being programmed.

Even most flash chips have the limitation that they can't serve out code while having other flash sectors being erased/reprogrammed.

So the simplest solution would be to have two memory chips. One EPROM or flash chip with a boot loader. But how (?) would that program get a boot loader when there are no stand-alone programmer available to program it?

The second memory could be a RAM or a flash, and could get the contents by the boot loader program.

But no - there would not be anything simple about the above. So we would be back to my original post.

Yes - a programmer can be written. Yes, the processor can be used. But it would cost. It would take time. And it would probably not work because it would require too many individual steps to be correct. And someone who starts from scratch would not have the equipment and experience to figure out all the broken steps until the design finally started to work.

A fraction of that time and a fraction of the cost, could be used to buy a development board with a modern processor with a RS-232 or USB interface where a PC program could send a new program. And with a modern processor that would have internal, hardware, support for debugging of the downloaded program.

Going the new route, would mean lots of time available to learn new skills on a working platform.
Going the old route would give lots of experiences that may not be wanted at this time. Like 100 different things that can go wrong ending a project in failure.

That's what I'd use in this sort of situation.

And what situation would that be? You starting from scratch, without any existing software? No existing hardware but a dumb processor and one or more UV-erasable EPROM chips but without any UV eraser? No tools to fill that EPROM with contents? No tools to drive raw processor pins to use as a building block for a programmer? No tool capable of receiving RS-232 data from a PC to send into latches to then (together with pulsing of address counters) program the EPROM?

Anyone who gets to this forum with the question the OP had, would be in a position where it doesn't matter what "can" be done. The important thing is that with lacking tools and lacking experience, lots of things that can be done just shouldn't be attempted. Becaus the cost would be too high. Because the failure probability would be too high. Just because other - very cheap - alternatives would allow much more learning in way shorter time.

If you have a $300 old car, it isn't meaningful to invest $3000 to try to get it to run a bit better.

If you have the skills and a truly unique wreck, it might be meaningful to invest $30,000 instead. Just because you will be able to create a museum-class vehicle in mint condition.

This is not a thread where an experienced developer is trying to recreate an important historical artifact, but someone who have a "wreck" on his hands and isn't realizing that the cost it would take to make it usable is higher than the cost of buying a new SDK complete with documentation.

List of 76 messages in thread
TopicAuthorDate
How to write programs to internal memory with RS232???      Jacob Drake      11/11/11 00:56      
   What processor      Per Westermark      11/11/11 01:05      
      And the winner is...      Jacob Drake      11/11/11 11:13      
         fuggetabutit        Erik Malund      11/11/11 11:42      
            Hmmmmmm      Jacob Drake      11/11/11 11:53      
               sure there is      Erik Malund      11/11/11 12:15      
               Costly failure      Per Westermark      11/11/11 12:20      
                  Well, the UV thing confuses me...      Jacob Drake      11/11/11 12:26      
                     well, then ....      Erik Malund      11/11/11 12:56      
                     OTP or mask-programmed      Per Westermark      11/11/11 13:00      
                     Isn't that a clue?      Richard Erlacher      11/11/11 14:09      
                  Wrong! It won't work with THIS part!      Richard Erlacher      11/11/11 14:08      
                     8032      Per Westermark      11/11/11 14:39      
                        Actually ...      Richard Erlacher      11/11/11 23:50      
                           What situation would that be?        Per Westermark      11/12/11 05:25      
                              I think you're confusing two different parts.      Richard Erlacher      11/13/11 01:09      
                           There's the thing!      Andy Neil      11/12/11 05:37      
                              It all depends on what you mean by experienced.      Jacob Drake      11/12/11 12:54      
                                 RE: It all depends on what you mean by, "experienced"      Andy Neil      11/12/11 13:03      
                                    "Level" is such a relative term      Jacob Drake      11/12/11 17:35      
                              That's the reason      Richard Erlacher      11/13/11 01:15      
                        8032?      Jacob Drake      11/12/11 00:47      
                           Yes - but is it worth it?      Andy Neil      11/12/11 04:30      
                           It's a long, circuitous path ...      Richard Erlacher      11/13/11 01:24      
                     I have an external UV EPROM      Jacob Drake      11/12/11 00:38      
                        If you don't know that, ...      Andy Neil      11/12/11 04:35      
         Unless you have specific interest in vintage electronics ...      Andy Neil      11/11/11 13:13      
            So...I've made a decision..sorta      Jacob Drake      11/12/11 23:51      
               One step at a time      Andy Neil      11/13/11 00:21      
                  Any specific one though?      Jacob Drake      11/13/11 00:28      
                     This one?      Andy Neil      11/13/11 01:04      
         Not this one!        Richard Erlacher      11/11/11 13:55      
            Hmmm, a goal?      Jacob Drake      11/12/11 00:44      
               Wrong road!      Andy Neil      11/12/11 05:07      
                  Regarding knowledge of electronics.      Jacob Drake      11/12/11 12:57      
                     RE: "fourth grade"      Andy Neil      11/12/11 13:10      
                        RE:RE:Fourth grade      Jacob Drake      11/12/11 17:36      
               if the "self taught home-school class" refer to the archaric      Erik Malund      11/12/11 08:17      
                  When throwing out bathwater, take care to retain baby...      Andy Neil      11/12/11 10:16      
                     out of sheer nostalgia      Erik Malund      11/12/11 16:44      
                     It might, in fact, be a good thing to go back farther      Richard Erlacher      11/13/11 01:37      
                        Interesting      Jacob Drake      11/14/11 00:15      
                           You need to know much more about two things ...      Richard Erlacher      11/14/11 12:51      
                  About other processors      Jacob Drake      11/12/11 13:01      
                     The prices were on the page!      Andy Neil      11/12/11 13:07      
                     SiLabs Boards      Michael Karas      11/12/11 13:42      
                     Integrated      Per Westermark      11/12/11 14:57      
                     here      Erik Malund      11/12/11 16:34      
                        Code flash not always able to replace EEPROM      Per Westermark      11/12/11 16:56      
                           agreed      Erik Malund      11/12/11 17:24      
                              Yes      Jacob Drake      11/12/11 17:42      
                              Yes      Jacob Drake      11/12/11 17:42      
               Maybe a heretic idea...      Matthias Arndt      11/13/11 04:44      
                  There's a problem with these ...      Richard Erlacher      11/13/11 12:56      
                     Not for the intended purpose....      Matthias Arndt      11/14/11 00:49      
                        Single source        Per Westermark      11/14/11 01:02      
                           Just another chance.....      Michael Karas      11/14/11 04:46      
                        If you read his entire post ...      Richard Erlacher      11/14/11 13:00      
                           I have six other microprocessors that i found yesterday      Jacob Drake      11/14/11 13:12      
                              Well, this is not the PIC forum ...      Richard Erlacher      11/14/11 13:37      
                                 I was just saying...      Jacob Drake      11/14/11 15:02      
                              'found'stuff      Erik Malund      11/15/11 06:31      
                                 I have to agree, conditionally      Richard Erlacher      11/15/11 10:08      
                           learning about microcontrollers      Andy Neil      11/14/11 15:24      
                              Arduino is a very good choice if not going 8051 route        Per Westermark      11/14/11 16:54      
                              Careful, now ...      Richard Erlacher      11/15/11 10:38      
                     spend some $$$ on an already-assembled product      Andy Neil      11/14/11 15:14      
                        in for a penny, in for a pound ...      Richard Erlacher      11/15/11 10:57      
                           Still easier to learn to program before bringing up first hw      Per Westermark      11/15/11 11:26      
                              I'm not so sure ... maybe we'll just have to disagree      Richard Erlacher      11/16/11 11:32      
               If you're really serious about this ...      Richard Erlacher      11/13/11 14:01      
                  tools and such      Jacob Drake      11/14/11 09:58      
                     Well ... maybe your Dad can fill you in on some details      Richard Erlacher      11/14/11 13:13      
         re: 8052      Andy Peters      11/14/11 12:57      
            Switched      Per Westermark      11/14/11 13:18      
            no offense, but that's incorrect.      Richard Erlacher      11/14/11 13:24      

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