I had some issues during yesterdays bike ride.
For a while I’ve had an interest in vintage typefaces. This interest stems from my efforts to reproduce vintage literature and the logos.
When I made my SCELBI front panels, one of the challenges I had, was to match the font for the SCELBI logo. Here is an image of the overall front panel.
and a close up of the logo.
Even though this is a variant of the omnipresent Helvetica, finding a digital font to match was harder than you think. After searching through dozens of variations of Helvetica and derivative fonts, in the end, I choose to use the very similar Helvetica Black. In some cases in the past, I have used Adobe Illustrator to manually recreate logos and such, but recreating characters accurately is extremely difficult and it is vastly easier to use off the shelf fonts.
It’s a pretty close match, but in reality the original logo’s characters are just a bit wider, so it’s not perfect.
I’ve known for a while that the single largest source of typefaces for printers and advertising people back in those days was Letraset brand rub on transfers. Back in the day, anyone that had anything to do with the printed word, would have had a Letraset reference manual, which contains hundreds of fonts and other visual goodies. Vintage Letraset manuals are available from used book sellers and even on ebay. Recently I picked up a 1981 edition.
One the first things I did when I got this guide was to determine if I could find an exact match for the SCELBI front panel logo. Here is what I found on the page with bold type Helvetica fonts.
If you ask me, plain old Letraset Helvetica Bold is an exact match and was the source for the lettering on the original panels. Now I’m just going to have to figure out the best way to digitize and scale the example letters found in the Letraset guide for my next batch of front panels.
Here is a popouri of parallel keyboard projects that I have been involved with designing.
At top is:
At bottom, from left to right…
Not shown are a number of projects that I have started, but not completed (yet)
And then there are the projects that never got past investigation stage.
It’s really hard to imagine that I have spent so much time mucking with simple parallel ASCII keyboard technology.
I helped with the PCB layout for this cute little dongle. It has a clear screen switch, which isn’t normally available on an Apple II keyboard and does the rewiring necessary to connect a stock Apple II keyboard to an Apple 1, Mimeo or other clone. These are not needed for replica 1s, which has the keyboard pinout necessary to work with Apple II keyboards.
Here is one in action, hooked up between the keyboard and the Mimeo.
They are being sold by seller vintagemicros on eBay: ebay listing
One word of caution – be sure to connect pin 1 of cables to pin 1 on PCBs. If you reverse them, you will probably blow the 7404 on the keyboard’s encoder board.
One last thing, I connected pin 4 of the keyboard socket to the clear screen input on the Apple 1. Pin 4 is normally not connected on an Apple II keyboard, but if you make the keyboard encoder mod to use the repeat switch as clear screen input as described on Wendell Sander’s site, it will work without any further wiring changes.
A few years ago I built a launch controller for Estes type model rockets. This was designed to be powered by a 12 volt battery. I usually use a battery off a riding lawn mower or motorcycle. When I was a kid I used to use a motorcycle battery that had a bad cell to launch model rockets and it worked great.
This controller has two cables that are used to carry power from the battery to the ignitor.
This controller has the following features.
Now the reason for this post. The last time I used this controller, I did have a rocket launch imediately when I inserted the safety key. The LED that indicates that the ignitor is connected was designed to draw 10 milliamps through the ignitor and that current is flowing when the safety key is inserted. Though I tested that current through a number of ignitors, it must have been enough current to fire the one that went off prematurely. What I have decided to do was to substantially reduce the test current through the ignitor. The easiest way to do this was to use a smaller test current through the ignitor and use a transistor to amplify the current to a level high enough to light the indicator LED.
Here is modified schematic. By the way, don’t bug me about the LEDs which are shown connected backwards in this drawing.
With this design the test current through the ignitor can be roughly calculated as:
12 volts/100000 ohms = 120 micro amps
I think that this tiny current would be extremely unlikely to launch a rocket inadvertently. I measured the current through the LED as about 30 milliamps. This means the transistor is multipling the current by about 250 times.
Here is a composite image showing the great progress that has been made on the 4 boards that need to be done for the SCELBI 8B.
Still a ton of tweaking and fine tuning needs to happen, but you can almost see the light at the end of the tunnel. I also need to find some time to figure out what I’m going to do for the custom chassis.
The backplane layout is for all intents and purposes done. The memory expansion card is next closest to complete. I haven’t done much with the PROM card, but I’ll do a complete review of it. The curved traces promise to require a lot of effort to match up to the original. The 4KSRAM cards need a lot of work and since the original has curved traces, it will take an extra effort to finish.
In a previous post, I noted how my Grandfather was a member of the Sightseeing Sixth Infantry Division in World War 1. I found a history of the Sixth Infantry in World War 1, written at the end of the war. The history can be downloaded from this site
Using this history and Google Maps, I created a rough map of where my Grandfather might have travelled. The routes from place to place are not exact, but the general areas where the Sixth travelled up to the end of the war are taken from the history. Travel from the LeHarve to the training facilities around Chateau Villain would have been by the famous 40 men or 8 horse box cars.
The other interesting thing that I learned was the extreme lack of transportation that troubled the Sixth Infantry’s movements. Horses were poor cast offs from the French army. Often the men hauled their equipment themselves, instead of relying upon horses or trucks. Once at the front, most travel was on foot. It is interesting that my Grandfather was a truck driver for a unit that apparently had very few trucks. The only mention of type of truck, was a brief mention of usage of some “liberty trucks”.
I have a mistake in my Brain Board Manual versions 5.3 (current version) and lower. On page BB:12, the last switch settings are incorrect.
Dual Bank Mode – Either high bank of Brain Board or low bank of Brain Board is selected
Switch 3 and 4 settings are backwards in the manual. When I get a chance I’ll update the PDF that is on my Brain Board web page. I already printed manuals for the remaining inventory of Brain Boards, so will hand edit those manuals.
My last “annual” ride to work day was four years ago.
Here is how yesterday’s annual event went.
The sun woke me up at 4:40 AM. – those who don’t live in Eastern New England probably don’t realize that in the summer the sun rises early here. Since I was up, I decided I might as well use the time and take my bike to work. I packed some work clothes, shoes, a towel and my laptop in my panniers. I reviewed my route using google maps, printed directions and headed out the door a little past 5:30AM. I didn’t get lost, even thought the directions are 3 pages long and include something like 40 steps on this years improved 27 mile route. By the time I reached the hills of Littleton and Boxborough, fatigue was starting to set in a little bit. However, I arrived a little after 8:00AM without too much difficulty. Due to the early hour, traffic was light and the weather not a problem.
During my work day, I checked the weather a few times and saw the temperature reaching over ninety. I figured I’d melt on the way home.
I left for home around 5:00 PM. Only one wrong turn this time, and I only went about 100 feet before realizing the mistake. While waiting to cross a road, a jogger mentioned that due to the heat, that it was heart attack weather. He was happy to take the break while waiting for the walk light. Though it was in the 80s, the humidity wasn’t too high, so the temperature wasn’t unbearable to me. Also, a tailwind helped me over most of the route. Unlike last time, I didn’t completely bonk. However fatigue was definately a factor for the last few miles. I reached home around 7:30.
5 hours on the bike and 54 miles is a lot for me in one day. However it is a lot more interesting than a hour on the freeway in the car. Who knows, maybe I’ll get in another “annual” ride to work in, before the summer is over.