This is really a part two of the series I started up on Sunday.
The thing I did after booting up the old guy was to immediately take him apart! This isn’t the first time I’ve done this so I was pretty confident that I wouldn’t have any issues with this latest attempt.
The beauty of the design is that after only three Phillips screws, you’re in!
The inside is so incredibly simple!
This is a revision A board at that. Sweet!
When I got the computer in the summer there was a murmur in the crowd wondering if it still had the SID chip or had it been harvested before the auction…
Here it is in all its glory:
The SID is the Sound Interface Device that made all the cool beeps and boops of the day. I remember one day making an analog-to-digital converter on a wire-wrap board when I was growing up. I eventually got the sound to play barely. It was the distinct sound of my mom vacuuming the upstairs hallway. (Even that was hacking the SID in a strange way… volume modulating the SID to do a primitive 4-bit digital-to-analog converter… It worked… once.)
Next up: the can.
Under the can is the VIC-II: The Video Interface Chip.
No doubt it was in the can to cut down on interference from the relatively high-speed signaling that’s required for video. The video colorburst is around 3.6 MHz and that would be required at least to make the composite output. The processor merrily is humming away at a mere 1 MHz.
Speaking of which:
Behold the brains of the C-64: The MOS 6510 processor running at a staggering 1.023 MHz. This is a variant of the venerable 6802 processor that gave life to the Apple II’s of the past. It’s virtually the same except it has a few extra I/O lines.
An interesting thing I noticed is an odd wire that looks like an late change to the run:
Looks kinda janky to me. :-P
And let’s not forget the memory. 64KB of memory.
How quaint.
My computer at home has 16GB of memory now.
But back then it was an expensive bit of kit.
More later on with this project… I still have to hook up the floppy!
LOAD “*”,8,1
Brings a tear to my eye…
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6502, 65C02, wow, I didn’t realize how close C64 was to Apple. I grew up loving Apple in the 80s but hating it with the intensity of 1000 suns by present day. Never had a C64 but picked one up at a yard sale for $5 maybe 10 yrs ago. Never fired it up though.
I’m pretty sure you can now buy a floppy-drive-hardware-level-emulator whereby you can download a torrent of every game ever, put it in an SDcard inside the floppy-drive-hardware-level-emulator, and get a menu to play every game ever.
Maybe not, but such solutions exist for ATari 2600, Intellivision, and ColecoVision. For Atari 2600 it’s the Harmony Cartridge. I just got it and will be hooking it up once I get that damned TV moved on top of my cinder block & wood shelf – http://www.flickr.com/photos/clintjcl/6172665240/
And yes. Odd wire is odd. Totally janky.
It really is an interesting thing that the schematic was so available — they GAVE it to you. It’s the same stuff that Woz wanted to do.
I did a bit of research on odd-wire and it’s there all the time… Looks like a 556 dual astable-multivibrator (no jokes… that’s the name of the chip!!). From looking at the datasheet that’s connecting the output to the trigger (http://www.national.com/ds/LM/LM556.pdf) Odd. I’ll have to look more into it when I get home. I don’t have a good pic of the markings but that certainly seems like a 556. I’ll check the schematic.
(Out in the Bay Area on business… (yes, I took the pics before I left (geek))) (balanced parens)
Honestly I was thinking of trying to rig up an arduino serial port driver to pretend it’s a 1541. Even /more/ honestly I’m happy I’m not the first person to have that though! :-P The tech book has all the signaling in all the detail that I’d ever need to get it working.
Re: the TV stand… the cats are in the way and are sure to complain. You, sir, need to build quicker before they claim it for themselves!
I ended up having to throw a party just to get enough people to lift the TV up to that stand. So I’m searching for Harmony Catridge torrent stuff, and apparently google has a new ‘your world’ serach, which put this as a result. I guess that’s useful.