Category Archives: Random Stuff

Processor and a monitoring panel (plus holiday oddments)

After the previous discovery that the -12V rail was collapsing under load, I read up on the datasheet for the 8080A processor. It states that the voltage rails must be brought up in a particular order (-5, +5, +12) and if the -5 is missing then there’s a very high chance of damaging the processor. The 8085 negated this and required a single, positive power source- the 8080 has strict requirements.
The 4116 RAM states that it should be brought up with the -5 first then the +5 and then the +12 but any of the rails missing should not cause damage to the chips. Bonus there.
So, I decided just to fling a processor at it. For $4 a pop, I decided that it was worth a shot, having fixed the power supply.


Same behavior upon power-up. At least I have a couple spares now.

repeating trash

Pulling the video RAM does show a different pattern on the screen so that at least is moderately positive- it initializes the memory in the same fashion each time it it switched on. Pulling the CPU and I/O cards and powering up the video card only liberates a solid beep, no crackling warbles.


Bought some little voltmeters from China- self-powered with internal self-regulated reference. They work from about 2.5 Volts all the way up to 30 which is impressive.


Also, bought some red transparent acrylic to serve as a mounting plate and to act as a contrast-improving device for the displays.

cut out

Marked up, cut with a hacksaw to size and sanded down smooth. Gently heated it up with my butane torch and bent it into a shape that stands up by itself.


Measured up for the meter locations, drawing the positions on the front in Sharpie.


Spread a thin layer of PVA glue on to each meter. It’s nice because it dries clear and doesn’t attack the plastics.

row of meters

Five meters stuck on and waiting for the glue to dry.

heat shrink

Trimmed the wires down to length and soldered on a length of multi-core wire, and using a spoon as a heat shield, added some heat shrink tubing to each join.


Soldered some test leads onto the other end of the cable and marked them up as to which is which.

plugged in

Got everything hooked up onto the appropriate locations on the PSU.

meter on

With a few labels to show what’s what (and a couple others because I got carried away) the output of the PSU is monitored fully. Everything is in spec, all loaded down with all boards fitted. Now that I have this set up, I’m happier in the knowledge that everything is doing what it’s meant to in terms of power.

Next up, pulling it all out of the chassis to get the analyzer clipped on properly.

new light

Back to the house, I bought a new 4′ Lithonia light fixture to replace the junky Lights of America one that refused to light one tube and barely lit the other. Wired it up, fitted the old 25W tubes and flicked the switch. Nice bright light with instant start, too.

recapped tv

Recapped a TV for someone at work. The ventilation grilles at the back had become lodged with dust due to the location it was kept in (TV stand with no access to the sides) and as such, had cooked itself. Uprated the heat ratings of the replacements (all the originals were 85C, the new ones went in all 105C with a few in really warm locations at 135C) and ran it for an evening. Worked well.


Traded the Challenger in against a new vehicle- Jeep Grand Cherokee. A bit more practical than ferrying the family around in a 2-door muscle car.

drip drip

Changed the ignition amplifier in the Renault and also a new distributor cap and arm, along with the crank position sensor. The CPS was at fault causing the non-running but the ignition amp appears to have been a bit marginal because it has a lot more torque now. Also, the power steering has stopped leaking and is holding fluid. The gearbox is leaking though, along with a weep of coolant onto the exhaust manifold that I need to find the source of because it smells when I start the car up. Other than that it is actually working moderately well.

Getting back to it.

It’s been a busy few months.
386 weather center

Flooded at work

Bad weather from Hurricane Harvey

With summertime storms looming on the horizon, weather that has made the yard grow like a jungle and homework assignments, sleepovers and movie nights burning up the rest of the time and energy I have, plus the house sapping the bank account meant I didn’t think I’d be getting back to any projects at all.

oxalis trianglularis

These strange little triangular plants have been popping up all over the yard recently. Turns out they are Oxalis triangularis, or “Fake Shamrock”. They are toxic to animals, and so far quite difficult to get rid of, but amusing and interesting to look at. Coupled with these, I’ve been getting waterlily looking plants popping up in the shade of the front path.

pinhole camera

We had a 75% covering of the sun from the eclipse, I was stuck outside at the cross-box in Thibodaux all day due to a fiber cut, but that wasn’t going to stop me from seeing the sun covered! Piece of cardboard with a small hole poked in it by mechanical pencil saw an adequate pinhole camera created, and the image above captured on a sheet of paper.

dirty generator

Picked up the generator from where it was chained up at the mother-in-law’s house. It’s been sat semi-covered in the shade for the past 7 years, and as such covered in all sorts of grime. Set about with a brush, bucket of water and Formula 409 and got it looking presentable again.

clean generator

Took the solenoid apart because it would click but not spin the starter motor over. The copper on the terminal connected to the positive terminal of the battery had gone all green (the steel nut on it was perfectly rust-free), where as the negative was all shiny but the steel nut had turned to a blob of brown rust. Chemistry is fun!
It needs a new battery but fired up on the old stale fuel in the tank- very surprising. Filled it up, along with 40 gallons of fuel in cans, in preparation. At that time it was unclear if we were going to be hit by hurricane Harvey. We saw some very bad weather (on the TV screen at the top of this post) but thankfully that was it.

living room furniture

Got some new furniture for the living room, which has allowed me to set up the old garage with the old furniture, a TV set and game console.

crepe myrtle and roses

The recent pleasant, cool, dry weather has meant I was able to get outside with a saw and heavily prune the plants on the northern edge of the property. There was a tree growing up through that crepe myrtle plant and the rose bushes were all woody. Does not look like much but that was a full afternoon’s work.


stripey clouds

Nice weather drawing to a close, meant that a bit of R&R could be had; much welcomed.

Odds and ends

Been busy with Scouts events lately. First off was the Raingutter Regatta, which is an event where you build a boat from a kit and then race against other people with boats by blowing at the sail through a drinking straw.

Didn’t win any races but the boats were decorated that morning with Sharpie permanent markers. We have the Cheshire Cat from the latest edition of the Alice In Wonderland films, and Edvard Munch’s “The Scream”.


That was a bit of fun. Next up was the Space Derby, which is basically elastic-band, propeller driven craft that fly along a zipline. Furthest wins, or first to the end of the run, which is about 30 feet or so of fishing line, held taut.


We went for a heavier design which won it first place in the races (not the fastest but it managed to gain the most momentum and coasted on by faster but shorter-traveled competitors). Designed after the P52 Mustang.

wheel off again

Took the wheels off the front of the car again, and changed the brake pads for new ones. The brakes had good pedal but offered little actual braking effort.


The pads were so glazed I could almost see my face. Plenty of friction material but all cracked up. In the bin they went. The brakes now work properly. That’s better.

Some new subjects to focus on

As mentioned in an earlier post, I recently acquired a Canon A-1 35mm film camera. It dates to 1978, and it was Canon’s first foray into fully automatic exposure cameras.

It gives a digital readout of the f-stop (aperture) and exposure time through the viewfinder using red LED numerals (which can be disabled), you can hold the reading for backlit scenes, calculate both, just the aperture or just the exposure time. Very innovative for the day, just focus and click. I got the pictures back that I had taken from being processed. Here’s a small selection:

Bayou Lafourche at Leeville
Bayou Lafourche at Leeville.

Experimenting with depth of field.

Leeville North, LA Hwy 1
Louisiana Highway One, at North Leeville. Once the busiest road in the area, now a ghost town.

Captain Thuan
Fishing boat, Bayou Lafourche, Larose.

It does have a light leak on the right hand side of the mirror. After a little reading, it seems that’s fairly common on these as the felt stripping that blocks the light disintegrates with time.

Pointe des Chenes

Compare with a modern digital image, adjusted with a warming filter. Quite different. I like both, but all the images taken with the Canon look like they could easily have been shot in 1985.

More illumination

Also, I didn’t take any pictures of the process because messy and Kerosene, but I got the red Coleman lantern cleaned up and running.

lit up

It burns brightly, which is good. New mantle from Walmart, some kerosene from the jug in the back room, the pump needs to have the leather bung replaced because despite oiling it, it doesn’t pump very well until it “catches” and starts to pump reasonably.

Coleman Model 200A

On a whim, I picked this up for $0.25 – it’s a bit of a mess but should come apart, free up and hopefully be useable.

Coleman dirty

Gave it a bit of a clean up.. looks a lot better- the tank is painted but the lid is red stove enamel.

cleaner coleman

The pump, pipes and everything are jammed up solid with old gooey kerosene and dirt, so that’ll be fun to clean. It’ll get there though. This one is more efficient on fuel than the bigger twin mantle one I have.

Film photography and a 386

I went to an estate sale at the end of last week and picked up a few things, the computer below and a camera, of the notably interesting items.


A 1993 Magnavox (Philips) 386 SX/20, with optional CD-ROM sitting on top. It was grimy on the outside, filthy inside as to be expected from an older system.


After a thorough cleaning, the Canon A-1 camera. 35mm film camera with fully automatic exposure (AE). View through the viewfinder (this shot before I had cleaned the lens and filter, so it’s a bit hazy) shows the aperture and exposure time in f/stops and 100ths of a second respectively.


It’ll calculate that and set itself if you leave it in fully programmed mode.. fancy stuff. Bought a new battery for it and a foll of Fuji 400.. have been shooting some pictures so once that’s finished I’ll see if they came out OK.


Got the computer running after giving it a thorough clean and fixing a couple contacts. Found a cable to replace the one in the back to link to the CD. Added a network card so it has CD interface, network and sound. Multimedia on a 386, before “multimedia” was a coined phrase!

cd working

Added a larger hard drive in (540Mb, or rather, 30Gb but partitioned down to the max the BIOS can handle without an overlay) and got the CD to read. 1x so it’s not fast but it does work!

Redux of the last few months.

It’s been a slow few months with little to report. I’ve lost faith in a few things, with a couple problems and issues with projects that had me baffled and I kinda lost interest in them.

However, things have picked up a little and I’ve gone back to the troubled projects or made some headway.

I bought some replacement tuning slugs for the Marantz receiver. They aren’t 100% the same permeability but they are the correct screw thread.


Replaced them in the transformer after carefully breaking the old ones up and getting them out of the core. Now I know what they feel like, the old ones were broken before I even started- the lack of decent radio reception certainly points to that.

radio waves

I got all set up and the thing refused to tune well. I could get a couple of strong local stations but the tuning meter and tune indicator would not light up, and those are partially controlled by the transformer. I connected my oscilloscope to the input side of the transformer to check the waveform was not distorted and all of a sudden, LOUD radio, strong signal! Uh.. yeah ok. Reflowed the solder, no effect.. touched the oscilloscope probe to the transformer again gently, and bingo. Strong signal. Touched my finger to it.. improvement. Okay, so it’s a capacitance issue. Experimented and ended up with a 10pF ceramic cap across the terminals to bolster the transformer. Now the selectivity and sensitivity are great. It’s right now the best radio I have in the house for FM stereo.

Carried on with it but now it keeps tripping out into protect. I’ve troubleshot the protect circuit, one of the other boards must have a leaky cap on it somewhere. I need to pull the boards power supplies off one by one and see what fixes it.

Next up, refinished the floors at the house. Edging strip all done in the kitchen:

kitchen skirting board

Finished up in the utility room, flooring strip and the paneling done:

utility room door

Finished up the cabinet around the water heater:

water heater

Pulled the stove to bits and thoroughly cleaned it, the glass particularly was vile.


Finished the floor edge strip in the living room, split the flooring between the two rooms where it was buckling and added a divider to allow for expansion.

living room floor

Rented a floor sanding machine and sanded the floors back, as previously they had looked OK, but having painted the walls and tidied up they were the least well-finished parts of the room.

floor sander

Solid cypress flooring. Smelled real nice when lain bare.

floor stripped

A few coats of polyurethane clear varnish later:


Looking much better. Also, picked up a nice Holophane light fitting on clearance for $4 at Home Depot. Fitted an LED light to it that has 4 segments inside, looks rather like a standard light bulb:

light fitting

Been troubleshooting the brakes on the car for a while. Stumbled across a post on a Ford Explorer forum with the same symptoms as mine. Turned out to be a faulty brake booster servo. I’m going to vacuum test mine this afternoon, have my MityVac for the purpose (shown here with brake bleeding catch-can fitted):


Also picked up a GTE Palco payphone, which has gone into service here at the house, with the requirement for coin removed.

GTE Palco payphone

I repaired a little Realistic PA amplifier that got struck by lightning, and built a cardboard speaker to test it with.

amp and speaker

Also cleaned out and got fixed up the Kerosene lantern, for hurricane use.

kero lantern

That’s about it for now.

Reflective! Also, frosty.

Bought a mirror from a gentleman in Canada.


Bottom one (old) being held up. Sunshine and humidity made all the silver fall off. The new one looks new by comparison.

Also moved the car and mowed because the grass is growing fast this season.


That’s 4 days’ worth of grass growing around here.


Also the new heater element arrived for the freezer. Not a day too soon, it was beginning to freeze up. That again was 4 days’ of ice.

Been taking up a bunch of time lately

Fun times with decorating the late grandmother in law’s house recently. It’s up for sale, and as such needed sprucing up a little.

Been attacking it with paint, mostly.

Master bedroom

Second bedroom

Third bedroom


Living room



Still a bunch to do.. but fun with getting everything recommissioned- digging up for new water line in ground that’s mostly gravel, shells and tree roots in July, fitting ductwork for the gas fired tumble dryer, fixing the electrics and so, so much cleaning.

Getting there. Slowly.