3
Jul
'21





13
Apr
'21

If you need an oscilloscope, or you have an oscilloscope that needs a service, Peter is your man*. I bought an Elteknix OS 620 from him, gave him my Hitachi V650F to service.

In his stash of stuff he had a large PCB with a 68000 on it. Obviously an arcade game of some type, I recognised the JAMMA connector. Gave me a bad case of the 10th Commandment. So he gave it to me.

Apart from the 68000 there’s also a Z80, in close proximity to the only surface-mount IC on the main PCB. Said IC is a MSM6295, a sound chip used in many games, so this does not narrow down what we actually have here. But some searching for the text on the ROMs pointed me at this ROM image, and some further searching gave me this auction.

So it’s a bootleg Street Fighter II.

It’s also to far gone to save, IMO.

Interesting mix of chips, very heavy on the programmables, with lots of GALs, an OTP 27512 and three HY18CV8 EEPLDs. I found the array of 74597 shift registers interesting, I wonder whether they shift the content of the rather large (10 Mbit) ROM / EPROM array straight out to video (maybe to create the background).

And interesting to note, it’s all on two PCB layers.

So now I’m conflicted as to whether I should strip it for spares or mount it in a lightbox for display.

*Assuming you’re in the Cape Town area, that is.





27
Aug
'20

My wife asked why I carry a gun around the house? I looked her dead in the eye and said, “Decepticons”. She laughed, I laughed, the toaster laughed, I shot the toaster, it was a good time.

Or in this case, the dishwasher. It was doing strange things so I took out the controller PCB to look for dry joints, etc…

What’s that at the top left? Looks like a PCB antenna?

It’s a CC2500 2.4 GHz transceiver.

OK, so some smeg products (this is a smeg LVS65W8A for the record) do have built-in transceivers. And there’s an app (terrible, terrible app BTW) to let you control them — but it’s limited to ovens and wine coolers and this is neither.

Maybe they use one controller for all their appliances, to reduce their inventory. But I’m not sure the reduced inventory cost would balance the increased BoM cost.

Or maybe my dishwasher is spying on me.

 





So the kid complains that the indicator lights on the one side of the Opel / Vauxhall Meriva stays on all the time. This is a well known problem, there’s a dual relay and the contacts burn and stick.

So I open the box up and give her a stick and show her where to beat the relay into submission lightly tap the relay with a stick to make the stuck contact release. Problem being that once that’s done, if you then lock the car the indicators flash and guess what? Yup, bloody thing sticks again.

Google tells me you can get a new one for under 15 Sterling, which at the current exchange rate is around three hundred rands if you hurry (the rand seems to be heading south a bit faster than normal right now). But there’s shipping on top of that and it takes a while so let’s see…

<ring> <ring> “Opel spare parts, how may I help you?”

Me: “Yea hi I need an indicator relay for a Meriva,  part number 09 134 880”

Them: “Yes sir, we have those in stock, one thousand seven hundred and twenty rands”

Me: “You Have Got To Be Shi, I mean, Surely that cannot be the case my good man?”

Them: “Oh yes sorry, my mistake, make that one thousand seven hundred and ten rands”

Me: “Kthanksbyeclick”

Not being a millennial, I do have some tools and spare parts. For VERY large values of “some”. This for example is my box of spare relays.

These ones look like just the thing.

Yup, it works. Cover doesn’t fit back on again, but it will with some surgery if required. I am not too concerned.

The kid’s father is coming down from the UK in two weeks’ time and he’ll bring down the Real Thing but in the mean time this will do. Very Nicely. R1710. Fsck.

 





A red one.

It’s a Type 4159 AB “Pluto” made in Czechoslovakia in the early eighties. Basically a 12V DC set, with a built-in transformer to turn 220V mains into 12V DC. This makes it nice and heavy — fortunately Turkish Air gives you 40kg baggage allowance.

They also bounce the bags quite a bit. Even wrapped in bubbles and spare clothing it still took a bit of strain. Fortunately the picture tube neck didn’t snap.

The story: we were in Prague, and it was a Sunday, and I had heard that there were flea markets all over the place, and the closest open one seemed to be Žižkov. So I got a tram ticket and headed off there.

Not as big as I thought it would be. They did however seem to have a rather large selection of lawnmowers.

Anyway, found the TV and two Metra Blansko multimeters (a PU-120 and a PU-140) for 15 euros.

The good news: It powers up. The bad news: Can’t get a station. The good news: I have the User Manual and Technical Manual. The bad news: It’s not in English.





25
Dec
'18

Last year Chris Otto wrote a text adventure style version of Dan Fogelberg’s Same Old Lang Syne. I like it a lot, so here it is.

Welcome to SAME OLD LANG SYNE: THE I.F. EXPERIENCE
Original implementers: Dan Fogelberg, Infocom.
Release 1.0 / Serial number 122416 / Post 2100.0

It is Christmas Eve, and a light snow is falling. You have been dispatched to acquire whipping cream for Irish coffee…

Grocery store
The holiday hustle and bustle is going at full steam. Carts squeak urgently across the floor. You smell gingerbread. Departments include fresh foods, a bakery, and, in the back, frozen and refrigerated foods.

>GO TO BACK OF STORE

Back of grocery store
The eggnog and apple cider have been well-raided. Scanning the shelves for whipping cream, you notice someone in your peripheral vision. She is wearing a blue coat and standing in front of a case of frozen desserts. Your heart skips a beat.

>WALK OVER TO WOMAN

You are now standing behind her, as she continues to examine the frozen pies. Without thinking, you gently touch her coat sleeve. She spins around, a bit startled, looking exactly as she did at age 20. After a short moment of confusion, she recognizes you, her eyes opening wide. The two of you move simultaneously for a hug. But, as you do, half the items in her purse spill to the floor.

>PICK UP ITEMS

Laughing, the two of you crouch and pick the items off the floor. The scene seems absurd to both of you, and you can’t stop laughing. You get a few odd looks from other hurried customers, which only feeds your laughter. Tears form in the corner of your eye.

After composing herself, she adds an apple pie to her cart. “I should go pay for all this,” she says.

>GO TO CHECKOUT

Grocery store checkout
You head up front together. The groceries are totaled up and bagged. The two of you make small talk, and the conversation lags a bit.

>WAIT

Time passes.

Through the big glass window at the front of the store, you see that it’s still snowing. The groceries are bagged up, and she’s ready to go.

>SAY SOMETHING

“Do you have time for a drink or two?” you ask.

She smiles. That old smile. “Absolutely.”

>EXIT STORE

In front of grocery store
You carry her bag as the two of you exit the store. The street continues to the north and south.

>GO NORTH

Northern end of street
You see two bars, but they are both closed. It is Christmas Eve, after all.

>GO SOUTH

In front of grocery store
The snow picks up a little.

>GO SOUTH

Southern end of street
Another closed bar. But there is also a six-pack store, still open.

>ENTER SIX-PACK STORE, BUY SIX-PACK, EXIT SIX-PACK STORE

Done.
Done.
Done.

“We should get out of the snow,” she says. “Let’s drink it in my car.”

>GO TO HER CAR

Inside car
You set the groceries in the back. The two of you sit up front. Snowflakes plop upon the windshield.

She hands you a beer and opens one for herself.

“To our youthful innocence,” she says.

>DRINK

Your score has gone up by one point.

>PROPOSE TOAST

“And to now,” you say, tapping her bottle with your own. You both take a sip.

Your score has gone up by one point.

The two of you are silent.

>REACH BEYOND EMPTINESS

You don’t how how to do that.

>WAIT

Time passes and snow falls as the two of you drink. The conversation turns to how your lives are now. She tells you that she married an architect; he keeps her warm and safe and dry. But then she pauses, clearly leaving something out. She never did like to lie.

>LOOK INTO HER EYES

They are the bright blue eyes you remember so well.

>SAY SOMETHING

“The years have been a friend to you,” you say. “You look great.”

Her blue eyes flash. You know that flash, but aren’t sure what it means this time. Doubt? Gratitude?

>WAIT

Time passes. The moment is lost.

“Your career must be going really well,” she says. “I see your records in the store all the time.”

You lapse into your standard reply: The audiences are heaven, and life on the road is hell.

More beers are cracked open.

>PROPOSE ANOTHER TOAST

You drink again to innocence, and again to now. Bottles are tapped and tilted upward.

Your score has gone up by two points.

>REACH BEYOND EMPTINESS

You don’t how how to do that.

>WAIT

Time passes.

You are on your last bottles now. She glances at her bottle. “Last toast, I guess,” she says, looking at you. “This one to innocence … and time.”

>DRINK

“Should old acquaintance be forgot,” you sing, and then you finish off your beer. She giggles.

Your score has gone up by two points.

It grows silent.

>EXAMINE BOTTLES

There are six empty beer bottles. You are starting to feel tired.

>SAY SOMETHING

What do you want to say?

>ANYTHING

You don’t have anything left to say.

“Well, it is Christmas Eve,” she says, finally. “I should be going. But it was so good to see you.”

She leans over and gives you a kiss.

“Merry Christmas,” you both say, simultaneously. You laugh again.

>GET OUT OF CAR

In front of grocery store

The store is closed now. There are only a few cars parked here. You stand and watch the tail lights of her car as she drives away. You start to feel a little lightheaded. You close your eyes…

…School, many years ago…

It is a beautiful autumn afternoon. The two of you are on the campus quad, parting ways. Sunlight pours through the golden leaves as she walks away from you, never glancing back. This is a familiar pain.

In front of grocery store

You are standing here alone. The snow has turned to rain.

 

 

 





Being the caring gentleperson that I am, I had to rescue the motherboard and power supply from this ex-PC.

P1140193r

Yea, I guess someone used it for a step, then lied to the boss and told him it had fried.

Because there’s nothing wrong with the motherboard, the PSU, or the memory DIMM that was kicking around loose inside the box.

This looks like a nice little motherboard for someone like me. It’s old enough to still have floppy drive support and new enough to have USB. It has an RS-232 serial port* as well.

But nowhere on this motherboard is there a part number of any type.

The BIOS is also not at all useful. CLE266-8235/M-6A6LUPREC-00 tells me the motherboard uses a Via Technologies CLE266 North Bridge and a VT8235 South Bridge, but this is not a Via motherboard, it’s a PC Partner. So with some more googling, turns out it’s a CLE266M-A68M800 (download the manual).

* The manual claims that there are two serial ports. On this motherboard, the RS-232 line driver and the header for COM2 is not fitted, so you’re out of luck there.





6
May
'18

So I’m messing around with a Burroughs TD831 terminal which uses a 6800 processor, 8 kilobytes of DRAM and 16 kilobytes of mask PROM.

The PROMs are fairly typical of the era, in that the chip select lines are also programmable. So you program the first one in a bank of four to have two active low chip selects, the middle two ones to have an active low and an active high, as well as the reverse, and the fourth one to have two active high chip selects. That way you can run address lines into the chip selects and four PROMs act like one PROM four times the size, effectively.

How I figured this out: the PROMs have 24 pins, the largest 24 pin PROM is a 2732. Told my EXPRO that’s what they were, not much joy. Went down to 2716s, and that gave data out of one of each bank of four PROMs. I figured that this means the devices are similar to for example the 82S191. So it was time to write some code.

I was lazy and just told the code that the three potential chip select lines were address lines. This gave me a 16 kilobyte per PROM dump, three quarters of which is blank Looking at how the banks were located in the 16 kilobyte address space makes it look like pin 21 (A10 on the 82S191) is an active high Chip Select, while pin 20 is A10 and pins 19 and 18 are the programmable Chip Selects.

I suppose I can rewrite my code to map things that way, but I should be able to paste my dumps together into something that can be disassembled. If ever I am arsed to do that.

But if you are here on a quest to restore one of these things to life, I think I have given you everything you need in order to be enlightened.

Edit: You might notice that I did change the code and re-dump the ROMs in nice neat 2k binaries.





29
Jan
'18

Prepping (i.e. making sure you have enough essential stuff stored away to tide you through a difficult time) is always a good idea. Now is a good time to start.

“Now” is an especially good time to start prepping for Day Zero. Here are some good ideas, except go light on the rice and dried beans (you need water to cook those) and buy water, not empty containers.

Successful prepping revolves around buying more of the kind of stuff you’d buy anyway, and then rotating it. Day Zero is not going to go full-on Zombie Apocalypse on us (we all hope) but the supply chain might be slow due to people having to queue for water, rather than being at work. If you also have to queue for water, and maybe go to work*, taking the time out to go to the shop will be a luxury. So shop now.

But don’t go out and buy a ton of freeze-dried Bear Grylls stuff you’ll end up never using and throwing away, just get extra stock of the tinned stuff you normally get, stick some extra chicken or mince or steaks if you can afford it in the freezer, that kind of stuff.

Remember to keep your plastic grocery bags, you’re going to need them :-/

Also, waterless hand cleaner and bleach. Paper plates might not be a bad idea either. A fellow student, back in the early nineties, kept his plate in his fridge so he only had to wash it once a week. He was just lazy, but if water’s scarce, it could work.

Start thinking about food recipes that need little water. I made this one the other night, it’s pretty damn good.

And have a Plan B. Always have a Plan B.

*Although how one can be expected to work when the toilets don’t flush is beyond me. Note that this also applies to the staff at your friendly local grocery store. Which brings us back to the point — shop now.





11
Oct
'17

iexplore.vbs is a nasty little virus (actually, not so little, the executable is over 5 megabytes) that infects USB devices.

How do I know this? The kid’s memstick was acting funny and while checking it out the virus jumped onto my home machine, from there onto my memstick, and I spotted it before it could jump to my work machine.

It moves all your files into a hidden directory, then makes a link to itself in the root of your memstick, with the same name as the memstick volume name.

So basically, if you see a link to your memstick inside your memstick, stop, don’t click on it.

If you’re not using Windows Commander, you’re on your own. Otherwise, navigate to your memstick and in the DOS prompt line at the bottom, type cd “ALT255” (hold down ALT, type 255 on the keypad, release ALT). This should put you in the hidden directory (unless your flavour of the virus called it something else, in which case, open CMD, dir/ah > file.txt, open file.txt in a hex editor, check what the directory is called).

Once Windows Commander is displaying the hidden directory, open CMD, dir/ah, attrib -h -s *.*, and erase those three files. Then use Windows Commander to copy your files back down. And don’t forget to delete the link and the hidden directory as well.

As far as I can tell, BICBW, if you remove all USB devices and reboot your PC, the virus does not stay resident on your PC — it’s USB only. But that could also just be the settings on my machine.





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