My debugging skills are a million miles from professional.
I do have an oscilloscope. So, I assume I would just put GND probe on (obviously) the GND pin of the cap and the signal to the other side?
What would a "clean" working cap look like on the scope?
Thanks!
Yep, scope ground clip to GND and signal pin/clip to the power trace or pin. Switch from 10mS to the shortest time base setting and look at the signal briefly at each setting. A clean capacitor would be a thin straight horizontal line.
Well all this cap suspicion is just wild guessing of course.
It's kind of unnerving to power up an old board, modern instantaneous voltages, hitting that circuit that's been dead for year's, if there was a way to slowly bring them back to life.
Well all this cap suspicion is just wild guessing of course.
It's kind of unnerving to power up an old board, modern instantaneous voltages, hitting that circuit that's been dead for year's, if there was a way to slowly bring them back to life.
An adjustable power supply would let you do that. Another option is to have a choke and capacitor between the power supply and the circuit.
I have a regulated bench power supply (30V 5A IIRC). But it only has one channel.
I sometimes get nervous powering on any one of my many vintage computers for that reason. Age of caps.
It may seem silly, but I've thought about storing them upside down. Granted, that isn't a guaranteed way to keep them safe but I would imagine an electrolytic capacitor leaking would have less change of spreading all over the board and just drip down. Sure, the board would be affected but maybe not as much? The keyboards they would drip on are a little easier to replace than damaged boards. Just a thought...
@cbmeeks said:
For those that don't know, I am a huge "vintage" computer / game console collector. I have around 60+ vintage computers and 30+ consoles.
I just landed me my first Amiga 1000. I'm a huge Amiga fan, BTW. This makes my sixth Amiga (500, 500, 600, 1200, 2000 too).
I'm itching to integrate a micro-controller (Propeller, hopefully) with it. Maybe as some storage medium. Might need an FPGA for that.
Anyway, just looking for any other Amiga fans out there. :-)
Since the PiStorm came out, I got myself a couple of A500plus systems to upgrade, so since I used to use Amiga's back in the day, I am now a ReNoob.
However, due to Tramiel being so stingy, the serial bus on the C64 was severely crippled causing the 1541 to operate much slower than it could. The 1541 was pretty advanced for its day.
This is why someone invented JiffyDOS, but it requires a ROM replacement.
@potatohead said:
We have a lot of a 6502 in an NES emulation someone did on P1. I should go and find it again...
It is missing decimal mode, and I am not sure it is cycle exact. Cycle exact is needed for disk I/O routines. Emulation of this is tough. Hardware 1451 simulators exist, but remain imperfect last I checked.
The ability to run code on the drive was used to make fast loaders and copy protection, among other things.
Re:Amiga
I'm a fan, but I stepped away from 16 bit computing, and did not use many machines from that era enough to be familiar like I am with most 8 bit machines. Instead, I was doing manufacturing related computing on the DOS PC and later on, modeling / engineering on SGI IRIX.
So, SGI is my "Amiga" type machine.
Yeah, me too, until recently.
And it's a bit much for hobby nostalga. 8 bits is enough for that.
Great computers though. I am frequently tempted to set one up to better understand what I missed!
Eric Ball also made a 6502 core in Spin. At one point, we were thinking of doing some emulation on the P1, but never got past building a few basic pieces. Additionally, a lot of 6502 machines do require cycle exact, and speed to do a reasonable job.
The cycle accurate part of the C64 is why it is probably easier to emulate an Amiga than a C64. Please, if you are still paying attention, ping Ada over in the P2 "Consoles" thread and give a good word for Amiga as her next project. It is quite amazing what she did with MegaYume and NeoYume.
@kwinn said:
Perhaps so, but after reading about the 1541 on wikipedia (https://en.wikipedia.org/wiki/Commodore_1541) why would you want to fully emulate it. Better to create an sd interface that is compatible with the C64 and actually works reliably and at reasonable speeds.
With all of the IO of the P2, perhaps it would be easiest and fastest to just connect to the cartridge and either emulate a Cartridge, and you could also control the tape port, which TapeCartSD already does quite well.
Hello!
@cbmeeks where are you based?
The Vintage Computer Federation, has a chapter in NJ, at the InfoAge site. They hold "repair weekends" every several months, and two great bashes every year. One's the VCF East, and the other is their holiday party. The next "repair weekend" is at the end of this month, and if you are close to where they are, they'd be glad to help out. I might even be there this month....
I believe there are few Amiga fans within the groups that meet there. There are certainly more than enough TRS-80 fans there.....
Comments
Yep, scope ground clip to GND and signal pin/clip to the power trace or pin. Switch from 10mS to the shortest time base setting and look at the signal briefly at each setting. A clean capacitor would be a thin straight horizontal line.
It's kind of unnerving to power up an old board, modern instantaneous voltages, hitting that circuit that's been dead for year's, if there was a way to slowly bring them back to life.
An adjustable power supply would let you do that. Another option is to have a choke and capacitor between the power supply and the circuit.
I sometimes get nervous powering on any one of my many vintage computers for that reason. Age of caps.
It may seem silly, but I've thought about storing them upside down. Granted, that isn't a guaranteed way to keep them safe but I would imagine an electrolytic capacitor leaking would have less change of spreading all over the board and just drip down. Sure, the board would be affected but maybe not as much? The keyboards they would drip on are a little easier to replace than damaged boards. Just a thought...
Since the PiStorm came out, I got myself a couple of A500plus systems to upgrade, so since I used to use Amiga's back in the day, I am now a ReNoob.
This is why someone invented JiffyDOS, but it requires a ROM replacement.
Yeah, me too, until recently.
The cycle accurate part of the C64 is why it is probably easier to emulate an Amiga than a C64. Please, if you are still paying attention, ping Ada over in the P2 "Consoles" thread and give a good word for Amiga as her next project. It is quite amazing what she did with MegaYume and NeoYume.
With all of the IO of the P2, perhaps it would be easiest and fastest to just connect to the cartridge and either emulate a Cartridge, and you could also control the tape port, which TapeCartSD already does quite well.
Hello!
@cbmeeks where are you based?
The Vintage Computer Federation, has a chapter in NJ, at the InfoAge site. They hold "repair weekends" every several months, and two great bashes every year. One's the VCF East, and the other is their holiday party. The next "repair weekend" is at the end of this month, and if you are close to where they are, they'd be glad to help out. I might even be there this month....
I believe there are few Amiga fans within the groups that meet there. There are certainly more than enough TRS-80 fans there.....
Three mascots.