Taking a BlackBox PCM Apart

[1998_K1500_Sub]

Z80 baby. Used to program in Forth, which suited my brand of dumb nerdity, you could plop assembly into it. I even recognized some of Z80 op codes back then. Now I can't even remember their name a minute after somebody shakes my hand.

Ditto, used Forth on a couple different platforms back in the early 80s. Once controlled a robot arm using Forth on a 6502-based platform.

Wrote FORTRAN on a Z80-based machine running CP/M DOS around then too.

Most of my assembly programming was on the 6800 in mid-80s, which is handy because the 16197427 ECU and others are 6800-based machines. Wrote assembly on 680x0 and DSP 560x0 uPs too. Fun stuff, loved it.

 

[someotherguy]

I totally embarrassed myself awhile back while looking at a manual Saab to possibly buy. It's been over 20 years since I've owned a manual transmission. I pulled forward out of the parking spot, and then tried to back up. It would NOT go into reverse for anything, and I couldn't figure out why. I even tried pushing down on the stick, and still nothing. Some other younger guys noticed I was having trouble, and came to help. One of them said to pull the lever, and I said I did.... then I realized what they meant. I had to lift up a sliding collar to get into reverse. I had seen that type of thing before, I think, but had forgotten. My manuals were older, and didn't have that safety type stuff on them.

My '65 Impala with the T10 4speed had a T-handle safety to pull up before you could go into reverse.

This is a pic from an auction for one off a '66 but same design; probably the same unit.

Sorry for the threadjack!

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Now I will admit when I got the '58 Apache "dually" with the NV4500 and custom shift knob without a pattern on it, very first time I did hunt for reverse a little bit before I straightened my head out. And it had only been a few years since I'd driven one, and that was also an NV4500 truck!

Richard

 

[VTSilverado]

@1998_K1500_Sub I really liked Motorola based procs (68x). Was a big Amiga fan, til they went bust.

Okay back, to what I'm trying to do, heh, I have to design a very simple PC board to fit these connectors, which I've never done before. I know what I want, but today wading through a free designer (Kicad) I downloaded is proving to be painful. It's great if you want to do something complex, with all kinds of symbols for components, but not so easy to learn if you just want to add some odball connectors, and buss lines to solder pads at the edge of the board (for the cable wires).

I might just design it in the ancient free Google Sketchup 8 (not the new Trimble version) as a graphic. It won't produce a Gerber file, but I'm just making one of these myself. Seems like I can just print out the design on my printer and use that to make the PC board with chemicals (ordered). You could really just do the same thing in a graphics drawing program, but I'm used to Sketchup for drawing anything.

I kind of feel like I'm cheating though, not using a real pcb designer. I should know how to do that. We'll see....

 

[1998_K1500_Sub]

... have to design a very simple PC board to fit these connectors, which I've never done before.

You're taking a modern approach.

My last printed circuit board (1984) was laid-out by hand using simple press-transfer templates bought from Radio Shack (pictured below). It was a I/O buffer card that plugged into the game slot on a Commodore 64, enabling access to some external A/D converters, D/A converters and interface peripherals.

I wouldn't rule out this approach, if one can find the transfers with pads on 3mm centers.

Then there's this... maybe this is more aligned with the approach you were considering:

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@1998_K1500_Sub I really liked Motorola based procs (68x). Was a big Amiga fan, til they went bust.

The 68000 was a great processor, one could code in assembly about as easily as writing in C, at least for simpler tasks. The converse was true as well, code written in C compiled very nicely onto the 68k instruction set. We actually deployed product with the last of the breed, 68060 processor.

The 56000 DSP was a different animal, writing in assembly was the only way to write efficient code. D@mn thing was fast though, in its day.

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[L31MaxExpress]

For the record I do not mind the nerd out session. I actually find it comical. I have swapped and tuned enough of the P01/P59s now that its benifits are well known to me.

 

[Road Trip]

I'm a nerd, what can I say.

Built a band sawmill from a snowblower engine and trailer wheels and hubs, cut the trees and built my house from the lumber. Built my first computer, an LNW-80 from bare boards, populating wi IC's and programmed my own EPROMS w/ tanning bulb in '84, wire wrapped a driver for a IBM Selectric typesphere terminal as a printer for it. Built a 32' houseboat in '89, and drove it w/ a 25hp Mariner outboard with a custom depitched prop 1700 miles down the IC and across Florida to the west coast. Lived aboard off and on for 10 years. Built two metal lathes from scratch and hand scraped them into bearing. Been casting iron in a home built furnace for 6 years. I own and run a '51 John Deere Model M, a '57 Ford 850 w/Pippens backhoe, and a Ford 3000 tractor and cut and split my own wood for heat. Last millenium I owned and rebuilt the engines on a '41 Plymouth p/u and a '57 Cornbinder ( IH S120 3/4 ton p/u). A couple years ago I built a 27 pound rowing fishing boat out of foam and fabric using only a used hacksaw blade as a tool. I did a youtube video of that one and apparently half a million peoiple were interested enough to watch it.

Is this harness I'm building practical? Nope. Will it even work? Maybe not.

nevertheless.....

From '89-'94 I got to live in VT and teach Field Service engineers from around the world
about how to troubleshoot a large VAX in production at the Digital mfg plant in Burlington, VT.

Did the lecture/lab thing with some of our best troubleshooters providing onsite support during
the day, and hang out with Vermonters like yourself in the plant during downtime between classes.
Needless to say, it was quickly reinforced to never judge a 'native Vermonter' book by it's cover.
Extra sharp & resourceful was a shared trait from the folks I rubbed shoulders with. :0)

Your commentary reminded me of the early part of my civilian career where I had my PDP-11
programming card, the diagnostic listing microfiche (organized alphabetically in a shoebox that
I had to keep up to date) ...a microfiche reader, some board extenders, chip clips, my trusty
Tek 475 o-scope, Fluke DVM, and a briefcase full of hand tools. (Oh yeah, plus the anti-static lab
coat and anti-static wrist strap that I always connected 1st to the machine I was attending to.)

Setting the flight times on a DataProducts line printer, deskewing the read/write heads on a
9-track tape drive, or reading the coder comments on subtest 46 to figure out why the CPU diag was
failing there. Toggling bit 7 on the front panel so I could set up a scope 'Loop on Error".

Always felt like I was drinking from the fire hydrant of knowledge set at max pressure. All of the
above is laughably obsolete today, but the lessons learned from those late night repair t-shooting
sessions served me well for the rest of my career.

Glad to cross paths with you & make your acquaintance. There is lots of quality talent from all
walks of life in here. So much yet to learn, hope my personal 'Best By' date is still visible in the
windshield of life, and not already in the rearview mirror.

Time will tell. ;0)

From one nerd to all the others in here, Cheers --

 

[1998_K1500_Sub]

I have swapped and tuned enough of the P01/P59s now that its benifits are well known to me.

Please educate me, anyone...

What's the difference / benefit of the P59 vs. the 0411? I've read the P59 supports / can support flex fuel and forced induction, but perhaps so can the 0411(?).

The P59 supports some fancy function with the AC too, I believe.

 

[L31MaxExpress]

Please educate me, anyone...

What's the difference / benefit of the P59 vs. the 0411? I've read the P59 supports / can support flex fuel and forced induction, but perhaps so can the 0411(?).

The P59 supports some fancy function with the AC too, I believe.

Like a desktop PC or Laptop each PCM family increased in processor speed and internal flash memory for both the ROM and RAM sections. The code became larger and the code loops run more quickly. The code itself was also refined by GM with time allowing it to run the powertrain better. Simple things like sensor reads of the various engine sensors are thus sped up and the PCM calculates the outputs more quickly. The quicker the PCM runs the fueling and timing code loops the more responsive the engine runs during transients especially. GM added more functions in the RAM of the PCMs as time went on so that it could store more adaptives that it learns over time and stores as adjustments to the base tuning. Inside of that RAM area has data covering functions like fuel trims, IAC adapts, transmission shift adapts, knock learning, etc.

 

[1998_K1500_Sub]

... each PCM family increased in processor speed and internal flash memory...

So should guys like @VTSilverado (and me, and others) be considering the P59 instead of the 0411?

My cursory review taught me that the wiring for a P59 is almost the same as for the 0411, so on the surface the decision to use the P59 sounds like a no-brainer.

I know just enough to be dangerous.

 

[VTSilverado]

Played around in SketchUP and did some measurements of the BlackBox boards and this is what I've got so far.

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