This is my new CoCo 1 computer:
Picked it up on the Bay for a price within my Retro hobby spending range and it was listed as working.
And as you can see, it does indeed work.
And it is in really nice condition.
I did some quick research before I pulled the trigger and found out this model wasn't the really early first model, which had the label to the left, not centered, and has the black keyboard surround extended even further than it is on this model.
This model shipped with 16K of RAM and I believe Color BASIC 1.1. It is RF only, not composite video.
It is not uncommon for them to have been upgrade with Extended Color BASIC and more RAM.
So, I when it showed up, I plugged it in (Yes, I still have a CRT television for some of my retro machines) and turned it on.
Color BASIC 1.1
No Extended Color BASIC. Then I typed "PRINT MEM" and it said: 14631
OK, so it is 16K. Not a problem, I believe I can address both of those myself, so it's all good.
The most important part is that it is in good shape and even all the keys on that chicklet keyboard are working fine! (When I was googling, I found out that can be an issue. Usually just needs to be fully taken apart and cleaned really well.)
The computer came with nothing else. No cables (the power cable is attached), no books, not accessories. (That joystick is an old PC joystick, more on that in a bit.)
So, about this time, you might be wondering about my subject like. "The nostalgic retro computer I never owned..." If I never owned one, why was it nostalgic?
Did my friends or relatives have one that I played? Nope.
Did any of my schools have them and I used them there? Nope.
But, one of my home away from home locations almost always had one running that I would use.
Yes, I was an early nerd and spent a lot of time at Radio Shack. And at least the ones I went to, frequently there was a CoCo set up, usually with MegaBug, and I would spend some time there. So the CoCo has positive memories for me.
Now, first thing I needed to test it on my TV was an RCA cable for the RF to the TV. I already have an RCA to Coax connector on that TV. Grabbed a cable for the test you can see above. Not sure if you can tell, but that image is a bit rough. I was initially planning on moving a composite video mod higher on the list of projects. Then I remembered that I grabbed a really cheap RCA cable for the test. So I found a much nicer one designed for video and swapped it, and the image looks a lot better! Still only RF, but good RF. ;-)
OK, next I want to test some software. But I have no carts (rompacks) or tapes. I did some quick checking on the Bay and at least an initial check didn't show quick impulse buy prices on what was available. So I figured I'd move to cassette tape software.
Did some googling and yep, the ColorComputerArchive has a bunch of programs/games in CAS and WAV formats. WAV should work for testing. Have loaded many a program over audio on my Apple //e. So, I need a cable.
I looked but couldn't find any 5-pin DIN plugs, so I ordered some on the Bay. But I am not that patient. ;-) So I made a cable that plugs into my PC with a mono 3.5 mm plug and some wire. Now, I didn't have the DIN connector for the CoCo yet, so I stripped the wire I was using (solid, not stranded) and folded it. Then I plugged the folded wires into the CoCo jack in the right spots.
I downloaded the WAV file for Color Invaders onto my old laptop, set the volume for about the middle, pressed play and then pause. Then on the CoCo I typed "CLOADM" (I did some research!!!).
I hit enter and then pushed play on the laptop. It found "Color"!! WooHoo! Waited a bit (under a minute) and the prompt came back. OK, no error, but... what now? So yeah, I did some research, but not enough. ;-) Did some more googling and saw I probably should have typed "CLOADM:EXEC". So, can I just type EXEC now? Try it, and Color Invaders starts!! OK, I unplug my cable which was just wires in the port to be safe. Then I try to start the game, and nothing...
More googling and, it needs a joystick. Quick check shows a lot of games that are just joystick.
So, I didn't have any CoCo joysticks. But I saw a Youtube video where someone had converted a 15-pin PC joystick to be used on the CoCo. I did have one of those (well two, but one is a Sidewinder 3D Pro flightstick so I'm not using that one) ... somewhere... I start digging thru my stuff.
And I find it! A 5-pin DIN. ;-) Of course, after I ordered a batch of them. Oh well, keep looking and find my old PC joystick (seen in the pic). The video did a good job of showing me what to do for that. Of course, that is a different DIN. A 6-pin. Hmmm... Isn't that the same as the Commodore IEC serial cable? I had a homemade one of those that I cut in half when I made my Pi1541. So there is another half around somewhere with the DIN I need! Back into my junk stuff, and I find that!
So, modify the joystick, solder it up. Type in a BASIC program to test it. I did NOT get it right the first time. :-) Had to swap some wires. But eventually got it!
Load Color Invaders, and it works!!!
Although my ship isn't going all the way to either edge? The BASIC program showed full range, so that's weird. Then I decided to check Youtube for a play video and yep. The ship doesn't go all the way to the edges. So my joystick and tape mods are working.
So, next step, download more WAV files. I don't see a way of knowing which games require more than 16K on the ColorComputerArchive, so I figure I will just sort by size (I am assuming that is file size) and start by downloading the smaller ones first. I download about 8 games, but only 4 are working.
Is there something wrong with my cable? Maybe the volume? So I start trying different volumes, and even a small external amp. I found that below about 30% on the volume control, I can't load anything. Every test above maybe 40% loads almost every time for the games that worked initially.
But the ones that didn't work would stop just after finding the program.
OK, I need to do some more testing. So I see there is a nice emulator called XRoar. I fire it up, set it for a CoCo 1, and test the non working CAS files. They work every time. ;-(
Maybe there was a problem converting some of the CAS files to WAV? So I figure out a few methods to convert them myself and get to it. One program (CAS2WAV) giving me a lot of options, so I create a BUNCH of different versions. I try them with different audio levels. They all refuse to work on my CoCo 1, but they work in XRoar. Hmmm...
Then when I was in XRoar, I typed PRINT MEM and... 22823. OK, that is more than 16K.
So, I start looking into XRoar configs. I find I can add a machine type, and I do that matches my CoCo 1. 16K, no Extended Color BASIC. Type PRINT MEM... 14631. Good.
Now I try to load that game, and IT ERRORS OUT the same way as on my CoCo 1. So, I test the others that didn't work and they all don't work. My problem is just those games require more than 16K.
Whew, everything is looking good now.
But the games needing more than 16K confused me a bit. One of them I know was an early CoCo game and when I find a rom dump from a cartridge (rompack), it is like 2K or 4K. So there no way that game "needed" more than 16K. But I check the start location for the program and it is above the 16K memory space. And then it clicked. This is a cartridge dump. Someone (I am guessing using a standard program/process) dumped some carts to tape, but the process puts the cart data in the space above 16K.
Just a theory, but that looks right and makes sense to me.
OK, another thing I ordered on the Bay was a pair of original controllers. (Apparently called Black Beauties.)
They were sold as non-working. One of them, the shaft is snapped. And apparently neither of the fire buttons work. I can work with that, so I ordered them. In the time I was doing the above, they showed up. I take the one without the broken shaft and check. Yeah, the fire button has no "feel" to it. Seems broken. But time to test. Plug it in, try to type CLOADM but I can't anymore. Turn off the system, unplug that joystick, turn it back on and everything is working. Hmmm... I wonder if that fire button is stuck ON (firing). I play with it a bit. Pulling on it a bit. Plug it back it, and it looks OK now. CLOADM and Color Invaders loads. I can move side to side! And I can fire, mostly. Still almost no feel. I'm surprised it works, but it does.
So I posted on the CoCo group I found, asking if it should have a feel (pop, click, whatever) when used, and basically it looks like it should. So I take the joystick apart.
Not a surprise, that is not a standard button (i.e. the kind/size you can buy today). I am thinking about ways to get a new switch in there.
But while I am doing that, I decide to try to take the button apart. I do that, and it's pretty simple. There's this little circular metal disc that when you press fire, it gets pushed in. The outside of the disc is touching one of the wires, and the center of the disc gets pushed down to make contact with the other wire. Except, the disc is almost flat.
I take the disc out and decide to see if I can make it a bit more convex. So I start doing that. All around the disc with a small needlenose. Just little bends.
Long story short, it eventually starts working! When I push it in, I can feel it, and it pops back out!!!
Put it all back together and test it. Seems good!
Now, this is not a great joystick design wise. This is an analog stick and there is no self centering (my PC joystick is self centering). And that is a weird position for a fire button. But it is working as it did originally.
So, one joystick is totally working! I did the same to fix the other one's fire button and eventually get it working also. Unfortunately, the stick itself is broken. He did ship me the broken part, so for now I have glued the two pieces together. I had to use a small washer to get a good seal. But it's together and working. If I find a broken one with a good stick, I might pick it up. Or just 3D print a plastic replacement. It's my backup (3rd) joystick anyway, so not super critical.
So, what's next? Well, I have three things for sure next, and a 4th as a probable.
1: Make some carts. I have an EPROM burner and found a PCB on PCBWay that should let me make some cart and use an EPROM (I had one from an older piece of broken hardware already) to hold a couple of games. Have the EPROM burned and waiting on the PCBs to be delivered to test.
2: Make an Extended Color BASIC ROM replacement. I needed to order the right size EPROM for that, so I did. I was going to order an adapter PCB, but the price was higher than I was willing to spend, so I'll fix the wiring (the new EPROMs aren't pinned exactly the same as the old ROMs, but close) with a socket and some jumper wiring. I think that will work.
3: Upgrade to 64K. It looks like the upgrade should be fairly straight forward with my Rev F (285) board. So I have some RAM on order as well.
4: Alternate, mostly because I have the parts lying around, is a Maxduino cassette emulator. I have a TZXDuino for my TS1000 for this and it works great. So figure I'll make with with the Maxduino firmware that supports the CoCo CAS files, and that will replace my laptop playing WAV files.
Longer term, CoCoSDC looks intersesting, and I am a HUGE fan of the Fujinet and see there is one for the CoCo. But that are both spendier that I am looking at spending for now. It does look like a composite mod shouldn't be too bad, but I like the look on the TV, so I'm in no rush to do that.
Drivewire sounds interesting and might be a good project, tho I will need a 4-pin DIN for that! ;-)
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