Apple 1 Replica-1 plus Case

A Little Background

There is a lot of interest in retro computers now.  I mean, back in the 1970s and early 1980s you just turned on a computer.  Now you boot up a computer and it starts hundreds of services or deamons (depending on the operating system.)  Back then, you had direct control of the computer, now it is more like fly-by-wire.  I mean, today when you type the letter ‘A’,  the computer decides where to put it, how big, and even if it will allow it!  Back then the computer just did what you told it, not what it thinks you want.  No antivirus software loading,  no spinning beachball, and no blue screens of death.  It just sat there doing nothing until you told it to do something.

But in the very early days of home computing, you were even more connected to your computer.  Before the Trinity (the Radio Shack TRS 80, Apple II, and the Commodore PET 2001) you had to assemble your computer from a kit.   It's like today for those of us that assembled our Prusa MK2, Mk3, etc. 3D printers.  We all remember the excitement of hundreds of parts in bags when our Prusa was delivered.  Then spending most of a Saturday assembling it. Then the release of endorphins when we turned it on and things started to make noise in a controlled symphony of movements as our first print of a Benchy began.

All this happened again when I built my Replica-1 plus computer.  The kit delivered was just an empty circuit board and bags of components.  A few hours later of sorting parts and soldering, I plugged it in and made some measurements with my multimeter, and then inserted all the ICs when I saw that everything tested good.  Then I turned it on for the first time.  I hit the Reset button, and there it was!  The ‘@’ prompt.  Just waiting for me.  Doing nothing until I told it what to do.  I entered a few numbers and the computer ran its first program.  It worked!  Not a complicated program, it just printed all the ASCII characters, but it worked.  Just like the useless print of the Batman thing on my Prusa.  I then started up the BASIC interpreter and wrote a simple program.  Again the computer happily did what I wanted and nothing more.  

Next I downloaded some old Apple 1 software and sent it through a serial port to my new Apple 1.  The first program was something called Microchess.  No graphics, just text scrolling up the screen.  Line by line it printed letters that represented a text based chess board.  I entered my move, then it printed, line by line, a text representation of the updated chess board.

I was so excited.  I called my 12 year old daughter to my office to show her this.  Her mouth opened up with a stunned look.  “That's how you played games on a computer back then?!”  It was.  In the early days, there really was no software to buy.  You found programs in Byte magazine, or The 99er, and typed them in.  Hours would be spent typing in BASIC code, and then you had a game.  Something about that simplicity and satisfaction is now lost.  

In a way, we have this in these early days of 3D printing.  We build a printer, design our prints, and print them out.  Just like the early days of computing.  We built a computer, wrote software, and ran it.  It's funny though.  When I built my first 3D printer I was often asked, “What can you use it for?”  That is the same question I was always asked with my first computer.  We now see how computers evolved and are now a necessary part of our lives.  I can only assume that 3D printing will follow a similar path.  Who knows, maybe there will be a whole retro 3D printing movement 20 years from now!

3D printers are an invaluable tool for restoring old computers.  Most electronic parts can be found, but many of the plastic parts are not available anymore.  But with some work, I have been able to find or design, then print many of the parts I need to restore my old computers. However, with this Apple 1 Replica-1 plus board, I needed a case.  And that is what I have here.  

There are only six known working Apple 1 computers, and are obviously VERY expensive.  The last working one I saw for sale had an asking price $1,500,000.00 for it!  But we can experience the exact same thing with the Replica-1 plus from Briel Computers.  I found the kit at ReactiveMicro.com. https://www.reactivemicro.com/product/replica-1-plus-from-briel-computers/  .  They are great to work with and have excellent instructions.  And the price is very good, almost one and half million dollars less than a real one!  If you have a little experience in soldering, you can have this thing working in a few hours if you take your time.  And for $50 more, you can purchase the board already assembled!

The first image is a render done in Cinema 4D with the Arnold render, and the second picture is an actual print.  The last image is a render in Fusion 360.  I printed my case in PrintedSolid's Jessie Beige 500, which has that retro color that works perfectly.  I printed the badge in Polyalchemy Elixer Lucid Pearl with Atomic Filament Jet Black Extreme PLA for the lettering.  I printed the two buttons in COEX Bone Brown PLA.  Of course many of the early cases that people made for the real Apple 1 were in wood, and you can always go that way.  Or maybe a wood filled PLA that you can stain.

This particular board did give me one challenge while designing the case.  Unfortunately, the two holes on the right of the circuit board were partially covered by a connector.  So I created clips on the right side, and screws on the left side.  So this is something to be aware of while putting the case together.  

Assembly

To assemble the case, first insert the two screws through the bottom of the case.  I used two M2.5x8 screws.  Next, place the Replica-1 board in place on the bottom making sure the two screws go through the board.  Then insert the two buttons through the top case.  Either use tape or your fingers to temporarily hold them in place while you place the top half onto the bottom half by first locking the right side into the small clip slots.  Then tighten the screws. The screws will cut the threads.  Finally, glue the badge onto the case.  

Things to consider or modify

First, the case is specifically for the Replica 1 plus, which is the last version produced.  Earlier versions will not work with this case without modifications.

While there is a power LED on the board, I did not make an opening for it on the case.  If you want, you can solder the leads of the LED to wires, modify this case to have a small hole, and attach the LED in place.  Do not mix up the polarity on the LED.  Maybe use a green wire on the longer lead, and white on the shorter lead (ground.)  I did not think this was necessary since there are small LEDs on the USB port in the back that I could look at if I needed to.

Additionally, the board has two jumpers.  The first one is for selecting either Integer BASIC or a modified version of BASIC that came on the Apple II.  The other jumper is used to select either an ASCII keyboard (almost impossible to find now) or the PS2 keyboard port on the back.  Once the case is on, you can not change the jumpers.  I left the jumpers set for Integer BASIC (since this is what was on the Apple 1) and the PS2 keyboard.  So make sure you have your jumpers configured properly before you assemble the case.

Next, if you choose to use an ASCII keyboard, then you will need to modify this case for an opening to run the cable to the keyboard.  Keep in mind that an ASCII keyboard will most likely require that the Replica 1 plus board is powered with both 5V and 12V since most ASCII keyboards use -12V.  If you need to supply power directly to the board (not from the USB port) you will need to modify this case to have and additional opening in the back. 

And finally, this case fits just the computer and really does not leave any room for an internal expansion card.  But this case can be easily modified to accommodate one.  I have no plans to install an expansion card so this is the way I designed. it.  However, I will post a modified version of the case in the future if I do add an expansion card to my Replica 1 plus.

I have included the STEP files so you can make any modifications to the case that works best for you.

Printing

Everything is oriented for proper printing.  No supports are needed.  You need to print two buttons (Apple1RepButton.stl.)  I used PLA for all the parts since this computer does not get warm at all.  Default settings will work fine.

As in most of my prints here, I designed this for myself but felt that others may find it useful. And please let me know if there is anything I can do to improve this print.  Good luck with your 3D printing, and retro computers!