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sailor
Registered: Jan 2002
Posts: 90 |
C64 Modding: LEDs / Switches
Hello All,
Not sure if this has been discussed here before, but can anyone provide circuit diagrams or connection diagrams for hardware mods like LEDs and/or switches.
Some stuff i can think of is displaying ZP$01 / VIC bank / drive reset / c64 reset / pause processor / data activity led for drive or serial channel / change(or ground) color bits...
I used to have few of these circuit/connection diagrams but they are lost somewhere.
Some of the stuff above is really easy to do, but is there a collected documentation of the stuff anywhere, feels unnecessary to invent the wheel again ?
Regards
Jani
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Frantic
Registered: Mar 2003
Posts: 1647 |
If anyone has something, feel very free to add it to http://codebase64.org
I would be happy to have such content there. |
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Devia
Registered: Oct 2004
Posts: 401 |
blah.. would be more interesting to build a "sniffer" board with display and backlog and ML/PLA/Clock/VIC translator/visualizationcapabilities'n'stuff... oh wait.. any decent Logic Analyzer does that ;-)
oh, almost forgot.. WHY?! |
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ready.
Registered: Feb 2003
Posts: 441 |
When doing such kind of things I use the 2N7000, which is a very cheap MOSFET switch. It is good because it doesn't load the line (pin) you are monitoring, in other words it requires a very small current to turn on. Then it can drive a diode. Use a 390 OHM (or similar value) to limit the diode current around 12 mA. The only drawback is that too many of these MOSFETs will cause capacitance effects that might slow down the computer operation, but the C64 is slow enough not to suffer of this problem. I successfully put around 10-15 MOSFETs in my modded C64.
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ready.
Registered: Feb 2003
Posts: 441 |
Oh, by the way: NEVER connect the series of resitor + diode directly to the pin you are monitoring or you will most likely kill the chip you hocked on to. Most of the signals in the C64 are just "signals" and don't have enough power to drive a LED.
So again, use 2N7000 or similar stuff as a buffer. |
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sailor
Registered: Jan 2002
Posts: 90 |
Thanks for your replies.
@ready.: I recall having BC547-transistors, but with additional 1kohm resistor on the "signal". I don't know the differance against the MOSFET solution ?
Also, do you remember where you picked the signals from (like IC and/or pin-number) and what their function were ?
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ready.
Registered: Feb 2003
Posts: 441 |
Hi Sailor,
the solution with BC547 might also work, but you need the additional 1kohm resistor to limit the base current from the commodore IC pin. The advantage of using a MOSFET is that the current is already limited, so you don't need that 1kohm resistor.
about the pin I used...well it depends on what you want to monitor with your LED. I needed to monitor the status bits of location $DE00, so I hocked up a bus comparator to generate the chip select signal for a 573 latch IC. The data bus was linked to the input of the 573 and 8 MOSFETs to the output of the 573.
Let's say you want to monitor the SID chip select signal, so that the LED blinks every time the SID is accessed for read/write, just connect the gate of the 2N7000 to the SID chip select pin (SID pin 8) and follow the scheme above for connecting the LED.
Here is the final result: http://fotoalbum.alice.it/alice/danieleredivo/engine-simulator/ |
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Mace
Registered: May 2002
Posts: 1799 |
Cool! Hardware mods!
A track & sector display on a discdrive would be nice.
Like, what you have in an Emu.
Any schematics for that? |
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ready.
Registered: Feb 2003
Posts: 441 |
here you find the file engine sim.zip:
http://mio.discoremoto.alice.it/danieleredivo/
it contains the schematics (beta version, could be improved, but they work as they are), a brief instruction of what this modded c64 does and a sample program adapted for a standard c64 (use a paddle if you have one).
I use this modded C64 at work to simulate the engine speed signal according to the fuel amount injected into the cylinders. In the sample program you can control the fuel amount with a paddle and the c64 responds according to the parameters of the engine (inertia, friction and load) solving a differential equation at 50Hz. The sample program uses the SID as speed output, while the real modded c64 send the speed signal out from one of the connectors as an open/close opto switch.
at the start of the program just hit return when asked teeth number. do not let the speed go over 700 rpm or I think the program crashes.
have fun!
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sailor
Registered: Jan 2002
Posts: 90 |
Hello,
Found a letter from a scener who had gathered some mods, i don't know if or which board revision this goes for but perhaps its same for all ?
Note: You do this on your own risk, these are not necessarily tested/verified and you will void the warranty :)
Any feedback/corrections always welcome!
Drive reset:
"Serial port PIN 6(reset)" + "pushbutton" + "ground".
Drive led/data activity:
"Serial port PIN 5(data in/out)" + "LED-circuit"
Display IRQ(SEI/CLI):
"Cartridge port PIN 4(IRQ)" + "LED-circuit"
Display graphic bank (2 LEDs used in this one):
"U2-6526 PIN 2(PA0)" + "LED-circuit"
"U2-6526 PIN 3(PA1)" + "LED-circuit".
"LED-circuit" corresponds to the circuitry mentioned above in this thread.
"Pushbutton" is a normal pushbutton used in electronics.
And again, you do/test this on your own risk!!
/Jani
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goto80
Registered: Jan 2002
Posts: 138 |
this one is a bit full on, but there are some nice features (although it's not really LED-visualizers and such) -> http://www.bigmech.com/misc/c64mods
i especially like the SID feedback thingy. |
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goto80
Registered: Jan 2002
Posts: 138 |
this one is a bit full on, but there are some nice features (although it's not a lot of LED/switches) -> http://www.bigmech.com/misc/c64mods
i especially like the SID feedback thingy. |
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Zyron
Registered: Jan 2002
Posts: 2381 |
That was a cool mod! |
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Zone
Account closed
Registered: Nov 2002
Posts: 7 |
Anybody know how to solder a data activity LED to the C2N port? :)
I have this cassette copier from Datel which blinks whenever something happen on the port. It's very exciting to watch while cracking tape loaders. ;)
In the 1980s my brother had soldered a speaker inside the datasette, so that you could find unused space by listening to those wonderful data sounds... The schematics probably came from the great 64er magazine. |
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sailor
Registered: Jan 2002
Posts: 90 |
Quote: Anybody know how to solder a data activity LED to the C2N port? :)
I have this cassette copier from Datel which blinks whenever something happen on the port. It's very exciting to watch while cracking tape loaders. ;)
In the 1980s my brother had soldered a speaker inside the datasette, so that you could find unused space by listening to those wonderful data sounds... The schematics probably came from the great 64er magazine.
An activity led should be doable, i guess a Load-it shows "activity" or mainly signal strength.
Why not post some piccys on the datel copier, perhaps the circuitry can be seen on that one.
Wonder if i dont recall seeing or hearing smth about some custom leds, but due to the phases(?) it needs a small circuit. Not sure, someone with knowledge please enlight..
I also recall an article in the 64er...
Regards:
/jani |
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Zone
Account closed
Registered: Nov 2002
Posts: 7 |
Interesting! The device is called "Datel Clonemaster." It is shaped like a "Y", and the idea is that you connect two datasettes to it, while the other side sits in the C2N port. Then you can supposedly make 1:1 copies of original games.
It's equipped with a LED, a resistor and a chip named "SP8812 DM74LSO4N". Hmm, some hardware guru might be able to shed light on this. :)
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Fredrik
Account closed
Registered: Apr 2009
Posts: 204 |
A picture of my C64-modding. On-Off switch to the power supply ;)
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GeoAnas
Account closed
Registered: Mar 2014
Posts: 41 |
Sorry to revive this old thread, but here is a link of some mods I did to a recently aquired C64 mobo ;-)
http://www.iamretro.gr/forum/viewtopic.php?f=12&t=1405
A switchless Jiffy/Dolphin DOS mod - Normal C64 kernal
An IRQ led viewer
A PLA led viewer
...more to come... |
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ready.
Registered: Feb 2003
Posts: 441 |
nice! Where are you located in Greece. Just got back from Pireus for job reasons and I was wondering if there was any retro activity going on there. By the way I found an Aneroussis joystick in great conditions set by the side of a trash container: I was so happy! |
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sailor
Registered: Jan 2002
Posts: 90 |
nice :) |
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TheRyk
Registered: Mar 2009
Posts: 2219 |
@link/pictures of board: cool CIA ^^ |
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GeoAnas
Account closed
Registered: Mar 2014
Posts: 41 |
Quote: nice! Where are you located in Greece. Just got back from Pireus for job reasons and I was wondering if there was any retro activity going on there. By the way I found an Aneroussis joystick in great conditions set by the side of a trash container: I was so happy!
Thanks to all ;-)
@ ready.
Did you find a "Tomahawk" joystick...in a trash bin?? Oh! This was for sure your lucky day!!!
They are heavy duty joysticks, made from arcade parts in a metal frame...practically invulnerable...
I am wondering who the despicable criminal of such a crime is! ;-)
< Off Topic Mode On >
There is lot of retro activity in Greece.
It could be better, but due to the prolonged financial crisis, every cent worths, so we all limited our retro purchases to an absolutely zero....
We have 3-4 major sites about retro computing / gaming and we know quite well each other.
I am located to North Greece (Chalkidiki area - Polygyros).
Here are some usefull links:
The site that I am an editor (and admin)...
http://www.iamretro.gr/
(Here is a link to Algo's interview ;-) http://www.iamretro.gr/introducing-algorithm/ )
A very friendly site, from my pals in Athens...
http://www.retrocomputers.gr/
Our local "RetroClub", we gather every Wednesday ... ;-)
http://www.retroclub.info/
"ComputeRevolution", an exhibition special dedicated to computer revolution and evolution. Most of the exhibits are part of our collections ;-)
If you fancy a virtual tour, please click here:
http://www.din.gr/ComputeRevolution/
This exhibition is still running till the end of June @ NOESIS/Thessaloniki
http://www.noesis.edu.gr/en/
<Off Topic Mode Off>
Last but not least...
Here is also a link to my YT channel, you can find lots of my Commodore's "peeks and pokes" there! :-D !LOL!
https://www.youtube.com/user/GeoAnas1/videos |
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ready.
Registered: Feb 2003
Posts: 441 |
the joystick I found is this type:
it was in a cardboard box with several VHS and 3.5 floppies, on the side of a trash container. I had the feeling it is very sturdy.
I could actually feel the crisis in Pireous: on the streets there were people from now and then pushing supermarket carts collecting things from the trash. And I really had the impression that these people have not spent their whole life like that. They had a different look from typical people who had lived their whole life on the sidewalk. So I guess they used to have a normal life, which dramatically changed for the worse at some point not too far back in time. |
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GeoAnas
Account closed
Registered: Mar 2014
Posts: 41 |
Oh ! Another great one ! I also have one of these "PACMAN" joysticks !
You can treat it as hard as you please...trust me on this ;-)
About your crisis description now...
I totally agree, I witness such pictures everywhere.Sad but true...it turns me furious against our politicians.
I've lost two of my best friends who passed away recently. Both at my age 46-47...Heart failure...too much stress and frustration...People are dying here !
I do not want to make any further comments on this...let's create with our trusty 64s, shall we ? :) |
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GeoAnas
Account closed
Registered: Mar 2014
Posts: 41 |
A video with all the mods I've done so far ...in action ;)
https://www.youtube.com/watch?v=Rb4airxZliY |
