B&S Engine starts but won't run

Nope -- No Dell. (I don't use Windows, FWIW.) But there was an intersting memory test published in the manual for the Motorola MC6809 CPU. It was a position independent program -- except for the checksum on the program itself. Once it is running, you could ask it to relocate itself and run in the memory just checked, so it could check the memory it just left. :-)

As it turned out -- running it in a chunk of memory was a better test of speed problems than running it *on* the memory in question. There was one board which had problems with rapid sequential accesses, so running in that memory would crash the program, but running on (that is, checking) that memory would never find a problem. It could not give detailed information on the particular bits failing, but it was enough to motivate me to retire that board and wire-wrap a board using 6108s instead.

And -- with today's memory size -- exhaustive tests can take forever -- walking bit or other tests. :-)

Enjoy, DoN.

That's it!

Thanks, DoN.

Apparently you still haven't finished with that Wine overdose. Reread your own original posting on this subject. You were defending Gunners lunacy.

I scratch-built my wirewrapped computer to learn how to design and program them instead of to use it, though the editor / assembler I wrote for it worked well enough to compose and print my resume. The I/O circuits were simplified versions of those in the IBM PC and the RS Color Computer.

It had a minicomputer switch panel with enough circuitry to write and display memory and vary the CPU clock, down to

What Tuesday wrote was |--Wieber claims he has good food sealed in argon since '99!

To which I replied |--Seventeen years is well within the typical 25 year storage life for |--PROPERLY PACKAGED grains and legumes. Sealed cans filled with any |--noble gas IS properly packaged. The problem is O2 in the air. You can |--displace it with nitrogen, carbon dioxide, or any inert gas or you can |--capture it with an O2 absorber placed in the can just before sealing. |-- |--At that age the nutritional value of flour is questionable but it's |--eatable and will fill your belly.

Where is any defense of Gunner?

OMFG Wieber is giving survival advice again!

Wieber brags that for 30 years he's been stocked up for 90 days minimum!

Wieber claims he has good food sealed in argon since '99!

Wieber has been dumpster diving!

Wait, what? Which one of those statements is not like the others?

"I called the local churches. I wasnt a mother in need. The food ran out. The lights and gas were turned off... So I went dumpster diving. And I sat in a house with no gas or electricity and ate my dumpster food, and shared it with my dogs and cats. We all were happy to have food. For two weeks."

The CoCo had a much better choice of CPU than the IBM PC. -- just not enough hardware to support the fancier disc controllers. :-)

O.K. Somewhat similar to the Altair 8800 (Intel 8080 CPU). The Altair 680b had a monitor program in a single 1702a, so you did not have to load a bootstrap from front panel switches -- unlike with the Data General Nova which I used for a while at work. :-)

Later -- I designed a specialized 6800 based system at work for an experiment with imaging and the effect of noise patterns on usability of the images. It generated range specified pseudo-random noise patterns (both offset and gain) and stored them in special wire-wrapped memory cards (more 6116s). Then the image clocked a different port to the memory to put the gain and offset on the same pixel each time through the image. (Only project that I was actually in control of which had co-workers doing some of the wire-wrapping for me, once I verified the first memory card to work. :-)

Later -- that got used for an additional experiment. Image was formed with a slow scanning mirror bouncing it -- and the display had the offset applied to it so the image stayed stable, but the noise patterns moved from side to side. That made a *big* difference in the usability of the image. It was rather like driving past a picket fence and being able to see what is beyond it, unlike when stationary. :-)

At first, the code got loaded via the emulator probe from a Tektronix microprocessor development lab, but that was a bit awkward, so I wire-wrapped another card to program 2716 EPROMs, since hand keying it all in to a Prolog PROM burner was error-prone. :-) I added the burn program to the control program I wrote for it, so subsequent updates to the program were easier.

Yes -- the 6809 would have been a good choice before the jump to

The real indication of the power of the 6809 was the Microware OS-9 operating system. Position independent and re-entrant code, and a multi-user multi-tasking OS running in 64K of address space or less. (And OS-9 Level 2 which required memory mapping hardware, but could make use of the full address space that the 68000, or later the 68020, offered.

The TI 9900 was an interesting CPU -- based on their 990 minicomputer -- but rather clumsy, especially in the initial implementation. Having 16 16-bit registers which were mapped into memory, so you could get a fresh set of registers by simply changing a pointer was nice -- until you realized the number of cycles that it took for any register operations. Later, they modified it so the registers had copies in the CPU chip itself, and a BLWP (Branch and Load Workspace Pointer) copied all of that region of memory into the on-chip registers, so any access to the registers was a lot quicker -- unless you changed the contents, at which point they still needed to be written out into memory.

The other thing was the weird I/O approach. It had an I/O space

I don't think that there is anything using the TMS9900 instruction set these days. :-)

O.K. No experience with the DSP world, though I was interested by the Motorola one, and still have the manual somewhere. :-)

A separate refresh process -- but it can be at a board level, so when nothing is accessing that board, it can be doing its own refresh operations.

Any idea how temperature sensitive that might be? I would expect shorter times near the top temperatures at which it could operate. (Faster leakage through the semiconductor insulators. :-)

Ouch! You've had them following you around. :-(

Reminds me of a patent claim and lawsuit for a particular bit of computer design. I read about it in comp.unix.wizards (IIRC) and it sounded familiar, so I went into where I thought that I had read about it, and found a description in the manuals for the CDC 6600, which predated the claimed invention date, so there was prior art.

Also -- we (a government lab) got a demand that we go through all of our oscilloscope probes, looking for ones which might infringe a patent that Tektronix had. (So -- we had to list everything that we found that was not branded by Tekronix -- including a couple of examples of a BNC, some RG-58 coax, and a resistor soldered to the center conductor. Obviously lab-made. :-)

Enjoy, DoN.