I believe random crashing is never really random, we just simply can't see the cause. So far, my favorite hair pulling trouble shooting story has been the one where someone could not enter 00 into the

#memory #ELF

If the loop back works, proving the physically connections are working, but nothing is ever sent to the TX pin (as measured on the ‘scope), does that imply the monitor software is still in the loop tr

#memory #ELF

From: John Kennedy <johntkennedy@...> Congratulations! Well, if you did it once, you can do it again. It's just a matter of figuring out exactly what you did differently when it worked. :-) I kn

#memory #ELF

John, that is great. Reminds me of some old saying, everything is hard before it becomes easy. Edison (or one of his fellow inventors) said 1% inspiration and 99% perspiration.

#memory #ELF

Well the IDIOT ran once! Not sure what I did exactly, but for a few fleeting minutes I was an 8-bit hero :-) I need to find the magic spells that will let me repeat it..

#memory #ELF

From: John Kennedy <johntkennedy@...> A few hints with IDIOT that might help: 1. It was written in the days of teletypes, and so expects a low baud rate. Try 110, 300, or 1200 baud. 2. It expect

#memory #ELF

Thanks Herb! I’ve been using your excellent pages for a few days now. And I’ve done exactly what you describe - first used the loop back, and then burned the IDIOT with variations into an ROM and trie

#memory #ELF

John Kennedy wrote: http://www.retrotechnology.com/memship/mship_test.html has a bunch of 1802 MC test programs and little exercisers of the 1802 and one's progamming skills. The last program, is Lee

#memory #ELF

Thanks all. I believe I have grok’d the way memory is laid out now. I’ve made an EPROM with blinking Q code and can call it where I can expect it! Next step is a monitor program. So far the serial loo

#memory #ELF

John, The worse part of pressing IN 32K times is by the time you get to 31559, the phone rings with a wrong number asking for 31669... oh crap! 1, 2, 3.... Chucks code is the perfect way to do it and

#memory #ELF

John Kennedy wrote: You're most welcome. For a software solution, Chuck's program (posted earlier today) will quickly get you going. :-) That's no problem at all, John. The 1802 can easily bit-bang hi

#memory #ELF

Thanks Chuck. Time to learn 1802! :-)

#memory #ELF

Thanks Lee. I’m afraid I don’t have the MC (yet) and this is a RC1802 system. I would like to explore the memory map, rather than stick the ROM at 0000, so writing a program looks like the way! Thanks

#memory #ELF

John, Here is a simple program that will display the ROM byte by byte to the Membership Cards LED's using the IN push button. 0000 90 INIT GHI R0 0001 a2 PLO R2 0002 f8 80 LDI 80H 0004 b2 PHI R2 ;R2 p

#memory #ELF

There was a program for the original Elf called ETOPS but that was limited to 8 bit addresses. Surely someone besides me must have extended it to 16 bits by now.

#memory #ELF

John Kennedy wrote: Hi John, It's not hard to do, but how it's done depends on what Elf you are using. If it's an 1802 Membership Card, the easy way is have the U2-LO jumper in place. That puts the RO

#memory #ELF

Is it possible to examine the contents of an arbitrary memory address, without pressing the IN button multiple times? I’d like to check if a ROM I am programming is where I think it is - but pressing

#memory #ELF