NEC PC-8201a Adventures – Part Two: Rebuilding the NiCad Battery Pack

These were great batteries, 40 years ago.

This was a good task to start on. It’d been years since I’ve done any serious electronics work, and my previous Arduino project, while successful, reminded me just how much I’d forgotten about electronics over the years. And my skills had mostly vanished too. So a nice easy project was just the thing.

About those batteries. They were amazing things back in the day. But when I opened the battery pack, it was revealed that they’ve done what all batteries do over time. Run out of charge and leak.  The corrosion wasn’t as bad as it could have been and the plastic package was in great shape — but the circuit board in the battery pack was beyond hope. 

First step was to remove the resistor and the connector. A few minutes with a hot soldering iron and some desoldering braid did the trick.  Then clean the contacts and leads with some CLR, followed by a good rinse and they’re ready to be used on the new board.

I had some old perfboard / prototyping board available so it was a rather simple thing to carve out a new one with a Dremel tool cutting disk. *PROTIP – CUT PERFBOARD OUTSIDE. THIS STUFF STINKS!!*

Then, rebuild the simple circuit to match what was on the original board. The power connections (Left (-), Right (+)) will be made when I solder the battery pads to the board.

If you look closely at the resistor, you’ll notice that I cracked the ceramic(?) coating and some chipped off. Since I had some replacements on order (though not the exact value so I’d be linking three in series) I figured ‘what the hell? If it doesn’t work, I’ll just do the series thing’.

But before soldering it on, I did test it and the value matched what it should be according to the NEC PC-8201a Service Manual. So maybe I won’t have to do the ‘series thing’.

The batteries in the NiCad pack weren’t meant to be replaced, so they were soldered together in series to form the 4.8V package. My goal was to make the batteries replaceable, which means I needed to fabricate the connections.

Rather than ordering the parts from eBay or wherever, and them taking 30-60 days to arrive, I managed to salvage the springs and plates from some dead solar-powered sidewalk lighting units.

They were a bit big, but I had some tin snips and they were soon cut down to size. Then run the Positive and Negative leads, a little solder and some stripped solid-core cat5 strands to make the serial connections, and the battery pack circuit was complete.

Having the resistor in the circuit makes our 4.8V pack into a 5.5v pack, which is within the input voltage range of the PC-8201a. The standard, non-rechargable, AA battery pack that was available for the unit didn’t have the resistor, and regular AA cells are 1.5V so that x4 gets you a nice, tidy 6V input voltage.

Next up, a good wash up to clean off 40 years of grime!

NEC PC-8201a Adventures – Part One: It’s here, now what?

Back in the early-to-mid ’80s, personal computing was finding it’s way. Desktop computers were becoming more visible in smaller businesses, but the work of computing still had to be done at the workplace. Portable computers were really just shrunken down desktops — they were called luggables at the time. Then came the revolution, as they say.

My first glimpse of the new wave of portable computers was not the Radio Shack (Tandy) TRS-80 Model 100, but rather the NEC PC-8201a – a sibling to the Model 100 (and the Olivetti M-10). All were made by Kyocera of Japan and based on the Kyocera Kyotronics KC-85. But the 8201a was the first portable I used that was actually a reasonably competent computer for it’s time.

Radio Shack TRS-80 Model 100
Kyocera Keytronic-85

Olivetti M-10

Costing about $1,000 ($2,600 in 2021) USD for a 24K model (yes, K as in kilobyte), it was a solid mobile computing platform with simple text editing, built-in telecommunications, and the BASIC programming language; supposedly the last iteration of BASIC that Bill Gates worked on before he went on to do other things.

Add a cassette recorder to your ensemble, and you could save your documents to tape, or load in other financial analysis and calculation programs. Plug it into a modem and you could dial in to CompuServe or GEnie, or a BBS (Bulletin Board System) and be charged by the minute for your online social media (we didn’t call it that back then) or gaming activity.

Fast Forward — about 40 years

Perhaps I’m getting to that age where the past begins to develop a rich, warm glow. I discovered that you could still find these portable computing pioneers available for a modest sum on Ebay. And with my recent interest in IoT (Internet of Things) devices, and microcontrollers (Arduino, Raspberry Pi), it seemed like this could be an interesting way to pass some Pandemic time.

I found one for a reasonable price and a few weeks later was the happy owner of the little unit in the image at the top of this story.

They’re really simple (by today’s standards) little devices. After unwrapping it and waiting for it to warm up — it was delivered on a -15c day so I thought I’d give the electronics time to clear any condensation — I flipped the power switch. And nothing happened.

To be expected actually. The Ebay seller had used an external power supply to test it, so I had to cobble one together myself to actually get it running. 5xAA alkaline batteries and a salvaged battery holder from one of my Arduino projects got me the power I needed to turn it on. Instant gratification! It worked, no smoke leaked out.

Testing and next steps

I put it through a quick test, loaded basic, ran a ‘Hello World’ program, made it beep, typed on all the keys, and gave it a good visual inspection.

Since the unit didn’t power up without an external power source, I knew I’d be taking apart the removable, rechargeable NiCad battery pack. So I did that next.

As expected, the pack was shot. Corrosion had crept across the circuit board and the battery pack didn’t look good. I was going to have to rebuild that pack and circuit board if I wanted to use rechargeable in it. Excellent, an excuse to research!

After determining the state of the battery pack, I built a list of things to do, and started checking them off. I’ll leave the list below, but the details, well those are words for another blog post.

Instructable: Arduino Keyboard Joystick Extender Box and Sound Controller Thing Using Deej

Update Jan. 23, 2021: Looks like the Joystick circuit has failed as it no longer toggles the Mute function. Well, I wasn’t too happy with the initial wiring job so this may be an opportunity to update that.

A while ago I developed an interest in Arduino microcontrollers, and this is my first ‘actual’ project.

It’s a box that sits adjacent to the keyboard and lets me control the output volume of various applications before they reach the speakers or headphones. Also the input sensitivity of a microphone.

Most of the magic is achieved through Deej, an application that sits in your task bar and controls the Arduino inside the box.

For more detail on my build, check out the Instructable.

Waiting Followers

(Character sketch and background for a Dave Gross Call of Cthulhu campaign: Horror on the Orient Express, 2016)

The club was lively; a typical Thursday evening at our usual retreat in Birmingham. When our schedules permitted, we traveled north to escape the din and bluster of London as the week ended. Benny Peyton’s Jazz Kings were taking a break after concluding their first set. They were glorious.

Standing, I drew the attention of my friends seated at the table. “Tonight,” I said, “I  am reminded that ten years ago to the day, I had a most extraordinary encounter with a most extraordinary man, someone who’s assistance and sponsorship shaped me into this prodigal Peacock!”

Chuckles responded to my statement — few hadn’t heard this story before.

“As you all know, my family came to this country from Warsaw when I was a youth. My father accepted a position teaching music with an academy in Kensington, and we established a modest house nearby.” 

“Of course, he also tutored me in the musical arts. And it is because of him, and this Mysterious Gentleman, that I am,  some say — and I’ll repeat for those who have not heard it clearly — it is because of them that I am this Magnificent Piano Prodigy!” 

Guffaws, and boos were the response I expected — I was not disappointed. I could play my friends as well as I could play a Steinway.

“Being from the old country, my father had a few old-country beliefs. The most amazing of which was that he believed there were ghostly creatures who could control animals and other living things, even the minds and bodies of humans!”

I paused, taking a sip of my gin tonic and enjoying the company of friends.

“Of course, our family, my sisters and I, hoped he would leave those ideas back in old Poland, and not embarrass us among our new friends and neighbours.” 

“But what amazing story would I have to tell if that were the case?”

“No, in the spring of my thirteenth year, my father brought home a colleague. Someone else who was interested in my father’s tales of the unbelievable. My father brought home Professor Worth!”

More boos and laughter from the table. Some of my friends had been students of Professor Worth and considered his alcohol-fueled lectures most entertaining if less credible. Why the University retained the 70 year-old archaeologist as a teacher was a wonder we shared.

I continued the tale…

—–

I had returned home from a typical day of unsupervised study and piano practice at the university auditorium. Having a father on the faculty granted a privilege unavailable to other thirteen-year-old students; access to the university’s Steinway & Sons grand piano — one from the Hamburg factory, not an American model.

Entering the foyer, I heard my father and another man in conversation. 

My home is where I met Professor Worth, who was listening to a description of the January Uprising, one of my fathers favourite subjects. I joined the two men.

“As you know, the Russian Empire was weakened at that time, having lost the Crimean war.”

“Yet,” he continued, “in Poland, they still had iron-control.”

“So why the rebellion in 1863?” asked Professor Worth. “The historical documents I’ve seen all refer to a movement to avoid conscription. You were there, is this not fact?”

“Yes, yes,” my father replied, “it is fact, but it is not  all the facts.” 

My father rose from his seat by the fire and began to pace as he spoke, “But what you’ll hear next isn’t part of any official history.”

“Among the rebels there was a group of men who not only hid in the forest to avoid the impressment patrols, but they actually conducted patrols of their own into the Russian camps. That much is known in the official histories,” he said. 

“That much is known to the record. What I say next is not.”

“They called themselves Waiting Followers. And they recognized each other by a simple star shaped tattoo.”

“There are stories of Russian officers mysteriously dying in their beds, not a mark on the bodies except for a star-shaped symbol carved into their flesh. They had the most horrific expressions — their faces grotesquely stretched and malformed.”

“It is said that the star-shaped tattoo of the Waiting Followers and the star-shape carved into the dead are identical,” my father paused.

“Other stories were told of Russian scout patrols who never returned. Search patrols often found no sign of the missing scouts,” he continued.

“Except once, they did find a missing scout patrol. Missing for three days, they were discovered standing in a small clearing deep within the local forest, a half-day march from the city.”

“Every man was standing in perfect formation, rigid, unmoving, at attention. It was as if they were waiting for orders. Yet every man was dead.”

“Again, not a mark on their bodies save for the carved star-shaped symbol. They were dead.”

My father concluded his extraordinary tale, “In the end, the January Uprising was crushed within a year. Reprisals were harsh; hundreds were executed and thousands exiled to Siberia and other remote regions.”

“And the Waiting Followers vanished, as if they never existed.”

Professor Worth had a few questions about particular details, which my father answered, providing such detail as he was capable. 

My father admitted that at the time of the January Uprising, he was sympathetic to the Russian Empire, and had friends who had commanded Scout Patrols.

I was thunderstruck as my father had never confided such things to me or my sisters. As Poles living in London it wasn’t prudent to admit past sympathies to the Russian Empire.

The professor then did a curious thing. Reaching into his valise, he extracted a small clay disc and showed it to my father, saying, “a few years back I found a shape, and others, carved into pillar formations we were excavating in Persia”. “I pressed soft clay into the carving and brought this relief disc back to continue research.”

It was my father’s turn to be thunderstruck. “That shape,” he said. “That is the the five-pointed star of the Waiting Followers”.

—–

My friends sat silent amongst the background din of the club. They’d heard the ghost stories before, but not the detail regarding my family connection to Professor Worth.

“So, my friends, to bring this circuitous tale to a satisfying conclusion, my father and Professor Worth continued their conversations about the Waiting Followers. Over the course of many years,” I paused. “Actually they became fast friends.”

“Professor Worth attempted to research further into the missing scout patrols and the Waiting Followers, but wasn’t able to produce any tangible results, only hearsay and speculation.”

“Upon my fathers passing, Professor Worth supported my application to the University, where I was able to continue my education on that very fine Steinway and Sons piano.” 

“But, unfortunately, Professor Worth was never able to verify my father’s story.”

“So now you know the full of it, regarding how I became an amazing, some would say prodigious, pianist.”

Chuckles again. And the band was getting ready to start their next set.

“And of course, it goes without saying — though I’ll say it anyway — a prodigious pianist of my calibre, is entitled to a little show of ego, a little brush of boastfulness, from time to time.” 

I raised my glass, “Thank you, my friends, for your forbearance of my foibles. I salute you.”

And as if there was a cue, the band started playing.


Leopold ‘Leo’ Bashinski – Musician

Musician

 May perform in an orchestra, group or solo, with any instrument you care to think of. Getting noticed is hard and then getting a recording contract is also difficult. Most musicians are poor and do not get noticed, eking a living by playing small venues as often as they can. A fortunate few might get regular work, such as playing a piano in a bar or hotel or within a city orchestra. For the minority, great success and wealth can be found by being in the right place at the right time, plus having a modicum of talent.

The 1920s is, of course, the Jazz Age, and musicians work in small combos and dance orchestras in large and medium sized cities and towns across America. A few musicians living in large cities like Chicago or New York find steady work in their hometown, but most spend significant amounts of time on the road, touring either by bus, by automobile or by train.


Musician, entertainer and self-styled ladies man. Enjoys attention to his Roman heritage, though also fiercely protective of his Polish roots. Curly hair, strong jaw-line and fierce, hawk like nose have granted him an inordinate amount of attention from the fairer sex. And he’s pretty good with his hands too. Yes. That.

For 3d Printing, Levelling the Bed is Finicky

IMG_0923

So a week or so ago I tweaked something on my printer. Maybe it was initial layer height. Maybe I adjusted a bed screw. Not sure, but all of a sudden my prints wouldn’t stick to the bed properly.

Using the ‘paper drag’ method of bed levelling ‘sort of’ worked. But it really was trial and error and very small changes in adjustment that seem to be working.

Prints are, once again, printing. Yay. #frustrating

IMG_0923

 

 

3d printing small board game accessories

Boardgame bits funnel tray - holding Fate and Honour tokens from Legend of the Five Rings (2017).
Boardgame bits funnel trays – holding Fate and Honour tokens from Legend of the Five Rings (2017).

I’m really happy when I can combine two of my hobbies. This time it’s Boardgaming and 3d Printing.

Often, many games have tokens or chits that are pooled for players to take at different times during play.  Usually, these sit in piles around the main game area.

On Thingiverse, swholmstead shared this neat design — which I promptly downloaded and printed.

From: Stackable Game Bits Funnel Tray by swholmstead, published Oct 3, 2017

Super Effective! Keeping the game table neat and tidy.

3d Printing Terrain for Dungeons & Dragons

Gateway.

Pretty cool what a little time, 3d Printing technology, some creative design work, and a spool of PLA will get you.

I’ve been testing various dungeon components to see how well they’ll work with our play style. And how good they’ll look once painted and finished.

Unfinished Crates

The crates above have yet to be finished. Usually, I prime them with Flat Grey, then colour, lighten or darken as necessary. This example also uses short walls, allowing us to see the contents of the room from anywhere on the table.

Surprise!

If you’re interested, I’ve been keeping all the landscape and terrain designs I find on Thingiverse in this collection.