Christmas Nativity 2020

The Christmas Nativity scene at Mah House continues to grow, with an expanded cast of visitors coming to see what’s going on.

A stable has been added to provide some shelter. An angel announces the news!

Christmas nativity scene 2020
Christmas nativity scene 2020

More shepherds have heard and brought some of their animals to join the rest of the visitors. A dog, another duck, and another penguin have also joined the pilgrims. The road to the stable is getting busy. I think next year we might have to extend the road.

Christmas nativity scene 2020
Christmas nativity scene 2020
Christmas nativity scene 2020
Christmas nativity scene 2020

Some new wise men and their camels have joined up with the wise men from the East and are continuing their journey. Commander Data has transported over to help guide them.

Cmdr Data has transported over to help guide the wise men from the East
Cmdr Data has transported over to help guide the wise men from the East

The newcomers are pieces we bought from a seller on Etsy and come from the same set as the other nativity pieces made and painted by Connie’s mom.

French Press coffee Mah way

It’s not difficult to find tutorials online for making French press coffee. I’ve tried a few, and settled on this method. It makes a cup that I enjoy black, or with a splash of cream.

My French press comes from IKEA, a 16 oz press (or a 32 oz press, depending on how caffeinated I want/need to be). You can find fancier ones out there, but these were reasonably inexpensive and do a perfectly good job.

Small (16 oz) on the left and Biggie (32 oz) on the right
Small (16 oz) on the left and Biggie (32 oz) on the right
New 16 oz Clemson alumni mug for scale.
New 16 oz Clemson alumni mug for scale.

I like to use an electric kettle to cook my water. Cooks the water quickly, pours nicely, and the one we have holds just enough water to fill the big press. Get one with an automatic shut off feature.

Electric kettle for cooking the water.
Electric kettle for cooking the water.

Most French press recipes call for very coarsely ground coffee and long brewing times. Since I don’t want to deal with having to adjust my grinder whenever I want to brew with the French press or Aeropress, I go with the same medium-ish grind that I use with the Aeropress. The grind size is pretty close to what you’d use for a regular drip coffee machine. I’ve found that one very heaping Aeropress scoop (17 grams or about 3 tablespoons) of coffee (double that if I’m using the big press) makes a cup of coffee that I like.

17 grams of ground coffee (about 3 tablespoons)
17 grams of ground coffee (about 3 tablespoons)

Dump the coffee into the press and add a tiny dash of salt (something I picked up from a Good Eats episode). I find it helps enhance the coffee flavour but doesn’t make it salty (unless you add too much).

Coffee into the press with a dash of salt.
Coffee into the press with a dash of salt.

Add water to about the top of the metal band, give it a bit of a stir, and put the press part on. I like to push the press down a bit so that all the grounds are submerged. Let it sit for about 3 minutes. Set a timer if you like.

After the brewing time, press the grounds all the way to the bottom, and gently pour into your coffee receptacle of choice.

Press the grounds and pour.
Press the grounds and pour.

The press uses a fine metal mesh to filter out the grounds, but really fine particles will still get through. Towards the end, I slow down the pouring and leave a bit in the press so that I’m not pouring all the fine stuff into my cup. That will help reduce the amount of sludge at the bottom of your cup. If you pour too quickly, the grounds get stirred up and you’ll end up with a bunch of sludge at the bottom of your cup. If you like sludge, then pour however you like.

Enjoy your coffee!
Enjoy your coffee!

Drink straight up, or doctor it up however you like.

Atari 2600 refurb plan

After going through a few forum posts, I think I’m going to start with replacing some of the capacitors and the 7805 5V voltage regulator on one of the Atari 2600s (the older one).

Physically the caps look fine but after who knows how long in storage, they probably need replacing anyway. There are three electrolytic capacitors, five mylar film (green chiclets) capacitors, two polystyrene capacitors and one ceramic disk capacitor I’m planning to replace.

I’ve replaced the video cord with an RCA-F adapter, so now the video signal will go through regular RG-6 coax right to the TV’s coax/cable input.

The power connector is a 3.5 mm tip-ring jack, which I’d like to replace as well with a more standard 2.1 mm barrel jack, but finding one with the right footprint is proving a bit difficult. That might be a second slightly more involved project.

Time to go shopping in my parts bins. I think I should have most of what I need already on hand.

Project: Atari 2600 Repair/Restoration

On the bench are two Atari 2600 video game systems that were given to me by one of the members of the local Slack community I hang out in. They’d been sitting in storage for the past few decades and didn’t seem to be working so he asked if anyone wanted them before they went out to the dumpster. I, of course, said I’d take them.

They’re of two different vintages based on the serial numbers, and came with a number of controllers and cartridges. For having been in storage, they looked in decent shape, although the older one was obviously sitting out in the open more than the other newer one.

The older Atari 2600 system.  SN 82227274
The older Atari 2600 system. SN 82227274

The 2600 isn’t too difficult to disassemble, and there’s already a pretty good Atari 2600 teardown on the iFixit site. This particular unit was made for Atari by Dimerco Electronic Corp in Taiwan and has serial number 82227274 according to the sticker on the back. I was able to brush off a lot of the dirt on this one, but it could still use a good cleaning.

Inside looked relatively clean with some tarnish and corrosion on the RF shield. No obvious issues with any of the components. From the silkscreen, this is a Rev 14 board.

Atari 2600 main board
Atari 2600 main board

Underneath the RF shield are the brains of the system: the MOS 6532 RAM-I/O-Timer (RIOT) chip just below the cartridge connector, the MOS 6507 CPU, and the Atari television interface adapter (TIA) chip at the bottom.

Underneath the RF shield; MOS 6532 RIOT chip (top), MOS 6507 CPU (middle), TIA chip (bottom)
Underneath the RF shield; MOS 6532 RIOT chip (top), MOS 6507 CPU (middle), TIA chip (bottom)

The RCA jack to the right is where the video signal goes out to the TV.

Initial testing of the two systems didn’t show anything on the screen. I ordered some RCA-F connector adapters (no idea these even existed until I started looking for them) to replace the RF modulator, and was able to get some images on the screen with one of the cartridges inserted. There was no response to any of the switches or controllers though, so more troubleshooting is going to be required.

Atari game on the television
It lives…sort of

I’ll need to do some more research on repairing and refurbishing these. I’ve found some potentially useful threads on the AtariAge Atari 2600 forum, so I’ll dig around there some more.

Project: Heathkit GC-1092A digital clock

Starting to tackle some of the projects that have been stacking up on the workbench. First one up is a Heathkit GC-1092A digital clock (serial number 00433). This was part of a collection from KB4NNM (SK) that was donated to the club earlier this year that’s been sitting on the workbench waiting for me to have time to get to. Decode Systems has a very useful page on Heathkit clocks.

Heathkit GC-1092A digital clock
Heathkit GC-1092A digital clock

Aside from a bit of dust and a few scratches and scrapes on the case, it’s in pretty decent condition. The clock works well, although the numbers flicker sometimes, especially when handling the clock. Haven’t tested the alarm capabilities yet. Setting the clock and alarm is done with a bank of switches on the bottom of the clock. A helpful sticker shows how to set things with the switches.

Setting switches for the Heathkit GC-1092A clock
Setting switches for the Heathkit GC-1092A clock

Removing 4 easily accessible screws from the bottom lets you take the top of the case off, revealing a fairly densely populated (for through-hole components anyway) circuit board and a big chunky transformer. Sitting in center stage is the brains of the operation, a MOSTEK MK5017AA clock chip (the white ceramic IC package in the center). There’s some corrosion on the heat spreader for the IC, but operation doesn’t seem to be affected.

Heathkit GC-1092A main circuit board and transformer
Heathkit GC-1092A main circuit board and transformer

The underside of the board has two large filtering capacitors, and the setting switches and speaker are attached to the case below the board.

Below the main board of the Heathkit GC-1092A clock
Below the main board of the Heathkit GC-1092A clock

The front panel contains the 3 2-digit 7-segment display units (Beckman SP-352). There are also a couple of 555 timer chips on the board, but I haven’t explored the schematic enough to know what they’re doing. Probably something related to the alarm function.

Heathkit GC-1092A display circuit board
Heathkit GC-1092A display circuit board

I’ll need to do some more research and studying the schematic to see if I can figure out the display flickering problem. Closing this clock back up and putting it back on the pile for now.