Tandy Color Computer 2: Ram Upgrade, Composite Mod, DIY Multi-Pak Interface
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- Опубліковано 25 вер 2021
- I fondly remember the CoCo 2 from my youth. I had an extended basic 16K Coco 2. That one is long gone, and I've been watching eBay for a while for a suitable replacement. In this video, I unbox a NOS Coco 2, and I immediately set to modifying it with period-accurate modifications. I upgrade the RAM from 16K to 64K. I replace the RF Modulator with one of Ed Snider's Composite Boards. I then go ahead and build a Multi-Pak Interface based on some gerbers that I came across on the web, and build a 3D Printed case for the DIY MPI. For more electronics projects, see www.smbaker.com/
- Наука та технологія
I remember connecting to other computers by using my Coco2 and a 300 baud modem that slid into the expansion slot. I learned all about programming in BASIC from that old computer. I may just have to get one for old-time's sake.
We live in a greast time for retro computing. Most components are still available and relatively inexpensive, and documentation can be found on the web. 30 years ago I would've never imagined a circuit board of my own design could be manufactured and shipped to me in about a week. The availability of other builder's boards are also part of the amazement.
i was 13 when my dad came home with the Color Computer 2. then later my dad came home with a multi pack. a disk drive & the speech synthesizer. we even had the trs-80 printer. i miss using the coco 2. it was the best computer i ever had.
Scott, I just noticed you used my cartridge shell design for this! Glad you liked it. I pulled my CoCo2 out of the box to play around with yesterday and decided I’d check around to see what is new, stumbling onto your video. Honestly, the CoCo doesn’t get as much love as it probably deserves. Great video!
#septandy is getting a bit thin, luckily this year (2022) there were some fortuitous additions
Great stuff! I've got 2 CoCo 2s that look new, the gent I got them from had them for years but never used them. Seeing the items you've got here I think I'm going to check them soon and see if I can get at least 1 of them upgraded. Thanks for the great content
i still have Tandy Color Computer 2 it came with floppy card it was given to me from friend use to live by me about 15 years ago
Just FYI, I was playing LOD on one of these around 1990
Thanks for the PLAY"ABC" tip, I never heard about that before !
I had the CoCo2 as a pre-teen, and got bored. One day I was (stupidly) using a jumper wire on the motherboard, just watching the computer crash in fantastic ways when I would touch random pins together. Amazingly, this didn't break anything.. but I did find two pins I could jumper, and the CoCo would have more RAM, but a smaller BASIC instruction set. The startup acreen didn't say Extended BASIC.. it was so ething else. Always thought that was interesting.
If you had one apart it would be a good time to put a larger heat sink on the pass element transistor in the power supply. This is more important on CoCo 3s as the 512k board for memory up grade increases the load on the five volt supply, they run a bit to warm to begin with. The supply is a linear regulator for 5volts. On the CoCo3 there is a lot less room in the box to use for a larger sink. Lots of people run a small fan. The 512 K board blocks some of the vents in the top of the case too.
just missed out on asking for an updated #septandy video, maybe next year .. (that CoCoVGA and any new stuff you built, aquired)
Maybe change that old voltage regular with a modern switching voltage regulator
I would love to see a redesigned 3D case for the Ed Schneider mega mini mpi. (MMMPI) The slots are super shallow and if "things happen" you will find the slots bend or broken. (I didn't do it but I had my rig at work and someone did something after hours and one of the slots were bent quite a bit. I straightened it and it works OK still but I can't think it would survive with too many such incidents.
Alternatively if you could make a taller lid or something that sits on top of the MMMPI? If you did, I would happily buy one from you!
The large power cap is severely swollen. Might want to replace it for a few bucks.
I had a CC2, but i think mine was 4K RAM
That computer uses the same CPU as CMI's FAIRLIGHT V Synthesizer you know the 6809E has the MUL instruction but no DIV instruction.
I am trying to diagnose a keyboard issue on a Coco 1 computer and hope you can help. Certain keys don't work and after looking at a schematic, I see that they are all associated with a particular pin on the keyboard connector. I tested continuity between the beginning of the keyboard ribbon cable and the relevant pin on the MC6822P chip and it is fine. Is it likely that since I don't have a bad connection, the chip is bad? If the chip is bad, do I need one specifically programmed for the Coco Model 1 or will any MC6822P chip due? I want to save this computer from the trash heap, so your thoughts are much appreciated.
The connections can oxidize over time. Sometimes just cleaning the connector helps. It's a flexible membrane, so carefully pull it out and use a clean white business card trimmed to fit the width of the socket and just work it up and down in the socket a few times, DRY.
Gently clean the keyboard membrane with isopropyl alcohol.
If none of this works, KeyFix replacement keyboards are available.
@@CoCoNutBob thank you. I will give it a try.
@@JamesBond-qv2ht I know it's tricky, but you might try watching the continuity on that pin while you type. It's rare but possible that the PIA chip is bad.
@@CoCoNutBob If they're socketed, an easy test would be to swap them. Coco should have two PIOs. if you swap them and the keyboard starts working and something else stops, it's either a faulty chip or a dodgy socket.
@@TheTurnipKing true... and CoCo 1s were pretty much all socketed.
Another trick is you can repair the conductive traces on the mylar with a conductive pen.
Seems to be holding up surprisingly well, even with lots of plugging/unplugging/flexing.
Huh. Australian flag behind you at the beginning. Hadn't noticed it before :-D
I think I've had it since I went on vacation to Australia back in the early 1990s. Fun trip.
Of the Heathkit brand
Some never even been opened
mine does that to with video
How many times do you need to stick a logo on a PCB.. and then why stick it in the copper layers.. and then why the hell stuck it in a copper layer with a trace going through it. That whole thing is just nuts.
In fairness to the original author, they did provide the Eagle SCH and BRD files as well. If I had scrutinized the gerbers more closely, it would have been reasonably straightforward to remove logos from copper layers. For other folks who want to do this, it is a relatively large board, and the "free" version of Eagle may or may not work on it. I have started a revision of the board, will make artwork available when I get done.
@@smbakeryt any update on the MPI? Any issues with the one you built?
@@CoCoNutBob As usual something else grabbed my attention to a new project. :) When I last used the MPI, I was not experiencing any problems with it. Seemed to work just fine.
Send me your email so I can send you pictures of all the boxes I have. They are still in the plastic wrapping
Edit...Edit
Are there no PCB manufacturers in Silicon Valley that would made the board for you.
If you have a suggestion for an alternative, I'll be happy to consider it.
Sigh… every retro youtube channel has made one of these… 😂