DistantStar001

I have a C16 with an odd video issue. Every once in a while, the video jumps up for a frame. For the most part, this has been a problem since i got it. However it also had signal corruption towards the bottom of the screen, and fro a while some characters would get corrupted after extended use. I've since replaced the TED and PLA (with a PLAnkton). That improved things, but the frame jumping still remains. Also there is ghosting, but that could be monitor. Anyway, any suggestions?

Just as the title says, it was working perfectly, and then it wasn't. Drive 1 spins, Drive 0 does nothing. It doesn't matter which drive is Drive 1. I looked up the error code and learned that it is either the 5630 or 6504. Unfortunately, I have no idea where to get the 6530. I checked eBay and the only ones listed are either part of a Kim 1 or an original ceramic package for $500 (and that's the cheaper option). Obviously, neither is an option. There are a few 6504s listed, but I'm not sure I trust the sources. Also, ArcadeComponents doesn't list the 6530 and the 6504 is out of stock. PolyPlay lists a MOS 901869 / 6530-048, but doesn't list the 4040 as a compatible machine. Is this part compatable? And if not, does anyone know where to get these?Almost forgot to ask: Laying odds, which one is most likely the culprit?

As you can see the + and 9 keys are missing, and more importantly, the plastic that holds the 9 key is broken off. Any Ideas?

Much as the title says, this was salvaged from an IBM 5151. The monitor was sadly smashed to pieces, but the CRT appears to be intact. I figured that at least some of it was usable, but with so little experience working with CRTs, I figured that I should ask first.

Unfortunately, what you suggest isn't possible on a PET. Or at least not my revision, as both AC rectification as well as voltage regulation happen on the motherboard itself. So there's no way to isolate the voltage lines from load. For that matter, the power supply itself is nothing more than a transformer, a fuse, and a really large capacitor. That said, you were right. The 5v line was being pulled low. The good news is that My PET is now fixed. Power wise, I had two problems. I had thought that the rectifier at CR2 was faulty because it was getting much hotter than its neighbor at CR4. However, it turns out that I had that reversed, as CR4 was staying cool because it wasn't passing current anymore. Replacing them both brought back the all three voltage lines, but the +5v was being pulled too low for the computer to boot. It wasn't until I removed the board and tried to power it upside down (I intended to measure the 5v line at the regulators to trace the short) that it came back to life. That told me that something was making inappropriate contact. So I popped it back in (absent the screws) and it powered on. Then I started adding screws, and low and behold, one of them had worn off the solder mask on the 5v trace to the rear cassette port and pulling it to ground.

Finally... SUCCESS!!!!!!!!!!!!!!! And the +5v issue was so stupid! The back screw between the two cassette ports had worn through the solder mask. A simple insulating washer and bingo! A working Commodore PET has re-entered the world!

Replaced both CR2 and CR4, as well as the only tantalum capacitor on the board (C51) and now I have +12v and -5v nearly spot on. The +5v line is another story. As at the moment, all I get is about +0.9v. Any ideas?

Update, in case anyone had any ideas. So I have a picture... or I had one. In a nut shell, and with a great deal of help, after the CRT was replaced and the VDU partially recapped, the issue was traced to the 470k Ohm resister at R260. Essentially, the negative voltage on the brightness control was too high for the CRT I have, and replacing it with a 47k Ohm resister brought it back into speck. Or at least this is how I'm understanding it. At that point, I had a picture, but with shimmering garbage on the screen. A quick Google search and the consensus of the good folks over at VCFed, and the problem was revealed to be two defective 2114 SRAMs. Replaced those. The screen was still wrong (lots of periods on it), but no longer shimmering. I notices that one of the 2114s wasn't all the way in the socket, and before I could do anything about it, the power cut out (on the computer. Not my house). Checked the fuse and it was still good. Then I checked the voltage. 12v was high at +17v. +5v was gone. -5v was low at less than -0.1v. In the course of this I touched the bridge rectifier at CR2 and found that it was extremely hot. CR4 (the same part) was cool. So I'm guessing that the rectifier just gave out. Any thoughts?

No it wasn't normal. Sorry I thought that I had added this, but the neck of the original CRT was broken past the connector. It's since been replaced with a comparable tube taken from an old Apple Monitor II with shattered plastics. The new monitor no longer arcs like that. The sparks you see under the CRT were going to coil that rests underneath. As for the ground wire, I've added one, but the frame it's mounted to is metal and provides CRT grounding as well.

I've picked this up again over at VCFed and am adding what I hope is a more compatible version of the original video in case it sheds some light. https://forum.vcfed.org/index.php?threads/commodore-pet-8032-monitor-problem-s.1242852/ PET Sparks.mov Long story short, I did a partial recap of the analog board and replaced the video chip on the motherboard with no luck.

IT WAS THE PROCESSOR!!!!! I would say it was a hunch. But the truth is that I have a couple of Z80s lying around, and a 40-pin socket or two, so I figured couldn't hurt. Also, I have no idea where to get a replacement ROM. And I have yet to get an E-Prom burner (really need to though). In any case, after I removed the old processor, it occurred to me that if that were the problem, then the fault screen would either resemble or be the same as what I was getting. so I tried it without the processor and got the same screen as before. Popped in a new Z80, and TA-DA!!! Working Aquarius! Also, to answer my last question. No. The Aquarius's behavior does not change without its keyboard. In fact, it boots just fine. Now that it's working, I've noticed some video quirks. For instance, the initial screen pic shown is monochrome. For some reason, my Samsung TV won't display any color with it. It has a similar issue with Atari 8-bits and Cocos. But usually changing the channel fixes that. The Aquarius, on the other hand, is strictly monochrome on this screen. I did get color on my little Sharp Aquos. But there was intermittent, but significant graphical glitching. Fortunately, it looks great on my old Sharp CRT TV from the '90s! Still, has anyone else noticed their Aquarius not playing well with LCDs?

Reset button turns the screen black, but the screen comes back exactly as before. Sadly, I was wrong. It wasn't the ROM Socketed, but one of the RAMs. Unfortunately, I don't have anything capable of burning E-PROMs. Is there someplace I could acquire one pre-made? Not ruling it out, but it is the part I have. I'll start looking for the ROM first. Curious. Does the Aquarius's behavior change without its keyboard? I'm probably grasping at straws, but I have a number of machines that can get finicky about that kind of thing. I know the RESET key works, but I can't say the same for the rest of it.

I dug out my oscilloscope, and started probing the pins on the CPU. In a nut-shell, I'm getting activity on all of the address lines, but none of the data lines. Pin 6 has a good clock signal and there is activity on the refresh line as well. However, the reset line is holding high immediately upon power up and stays there. So I don't think I'm getting a reset signal. Please tell me that signal is not generated by either of the ULAs!

Sadly no beeps. For that matter, no response at all to any keyboard input (except reset).

Like the title says, I just received a Mattel Aquarius but it isn't working. Power light comes on. It responds to the RESET button. But all I get is a garbage screen. I tried reseating the only socketed IC (I think it's the ROM), and tried booting without it. The only difference was that instead of the characters shown there were small rectangles on the screen. However, they were in the same locations on the screen. Any ideas?

Thanks, but too bad I don't have the drive for it. But I probably wouldn't have much use for it if I did. As it stands, I can't even get it to access the hard drive. Still working on that. Got it to work. And it even stopped beeping errors at me once I set the dip-switches correctly! Eventually I even got it to boot from a floppy instead of dropping me into BASIC. However, I have to wait to insert it until the drive lights up. If I put it in too soon, or leave it in between boots, the computer drops to BASIC. One would think that as long as a disk is in the drive, the drive would read it, but apparently not? Still don't know if that's normal. XT. It's a silver badged Model M. Unfortunately, it's the one with the lock lights that the XT can't operate, but it works and close it's enough for now. The Hercules Card has one, but the VGA Card doesn't. Eventually, I hope to find an IBM 5151. Then I'll put the Hercules back. I'll look into that. But for now, I was thinking of adding a Gotek as my second drive. The B drive I have isn't reading disks, and the Gotek would allow me to transfer disk images to real floppies for some of my other computers with minimum setup. As it stands, my primary (modern) computers are Macs. And they network through WiFi. A hardwired Ethernet setup would be a little difficult at the moment. But eventually... Sounds like fun!

It isn't easy to see in the picture I posted, but this is the port on the back: Seems like a bit of an overkill for a cassette drive? What would connect to it? Not sure... I didn't think so at first, but then I took out one of the cards in question, and I think this is compatible. Yes, I have an IBM model M. But I hadn't connected it. Turns out that was the error. Now I get a single short (apparently happy) beep!

Just got an IBM 5160 XT in pretty rough shape. Cosmetically, it was looking pretty decent on the outside, but internally, that's another story... First, it was almost filled with what turned out to be powdered laundry detergent. I've gotten most of it out, but it seems to have had an unfortunate effect on the black paint on the lower case. Much of it seems to have crumpled off and when I ultimately had to wash out the detergent, much of the deteriorated paint went with it. Question one: Any recommendations on a touchup paint? I'm not too worried about the inside. But it would be nice to get the exposed parts of the front panel. To be clear, before I cleaned it all the paint was present. This was the detergent, as the most affected areas coincide with the heaviest concentrations of detergent. The motherboard is clean now and I can't see any corrosion on the board itself. All the IC legs look shiny and metallic. Unfortunately, the capacitor at C58 has blown out on the right side. (Not sure that the direction of the explosion matters, but there it is all the same). It's since been removed. Looking it up, it appears that it (and C56) was unnecessary. So I've elected not to replace it for the moment. Overall it looks good (minus the offending capacitor) Once cleaned, and reassembled, I tried a power test. From the sound of it, the hard drive is spinning up, but makes a knocking sound as it does. If it's bad, I have a spare. No idea if it works, but I have one. The floppy drives light up in sequence. Heads move. So until I can check with a disk, I'm assuming they're fine. At least, I have no way of checking until I get a compatible monitor! Following all this, I get two short beeps. Which I think is expected? (lack of monitor and all) Question: The machine came with a Hercules card installed. Unfortunately, for the time being, I don't have a compatible MGA or CGA monitor. What I do have are two 486s with VGA cards installed (at least one of which is on the fritz) So I'm wondering if such a card would be compatible with the XT? I want to get an MGA Monitor eventually (preferably a 5151, as I love green phosphor). But until I do, I'll have to make do with the LCDs I've got. Last are the cards installed (and in order from the PSU down). Not sure who made it, but it was attached to the HardDrive. So I'm assuming that it's the controller. No idea! Haven't looked it up yet. From the port on the back, I'm guessing another drive controller of some kind? Floppy controller. Again, no idea. If you can't tell, I'm not too familiar with PCs... Video card. I did look that one up. That's it for now. If anyone could tell me what I've got, how to get it working, or if I'm even on the right track, it would be appreciated! Oh... Also, any upgrades or accessories that might make this more usable going forward. I'm not looking to max it out, or turn it into another 486 or anything. Just run simple games and hopefully make floppies for some of my older 8-bits. TRS-80, BBC Micro (if possible)... Whatever I can't figure out through alternative means. Additional question: Where can I get some new cork feet? It's missing two, and the remaining ones have seen better days!

Hi all, and thanks for the responses! Sorry I didn't reply sooner, but your advice is appreciated. I'm guessing an RGB Breakout or VGA converter are my best options. But I'll have to research my available screens. Good to know! I won't use one. Also good to know, since I have those! It was just something to play with. I wasn't thinking of making it my primary 64 experience or anything like that. I have several real Commodore 64s, TheC64, and a Commodore 128 for that. But I'm guessing that the ZX Spectrum emulators I've found won't be much better. I'm told it does a pretty good Mac though... (or do I need additional hardware?) Wish I had a SCART capable TV. Sadly, not very common where I live. My Gotek is running FlashFloppy 3.33 and OLED-equipped... So how do I access the menu? Even if the C64 thing's a bust, it might come in handy for other programs. Side question: Can I add a tag to the file so the Gotek knows it's locked from the start?

Thanks for this! I have an external PC 360K drive that might work. But I'll probably need to make a new cable for it. I made a similar post on VCF, and it was suggested that they might be for enabling and wright protecting a RAM disk. Basically, if they're right, I can load a ROM image into RAM. There's a battery on the board (likely dead, but thankfully not leaking) that would preserve the image between power cycling. ME TOO!!!! Below are some pictures. If anyone could tell me what the rooms are it would be appreciated.

Update: IT WORKS!!! I had to reset that Sidewise board more times than I could count. But eventually, I got it in. All keys have been tested good. Also, I've left the PSU at 250v for the time being, as I like keeping my machines as original as possible. On boot it displays: 32K OPUS DDOS 3.45 BASIC >_ BASIC programs work as expected (when compared to my Electron, but a little faster). Not sure what Opus DDOS is, but I have it. As for the two switches on the back... No clue. Switching them up or down has no impact on boot behavior. Still looking into the other ROMS. Will post a picture of the board soon, but for now I'm going to play in BASIC!

I finally got my Amiga 500 to work! It only took me 2 years to find a working power supply. Long story. I had been using a PC PSU, but there was smoke. Several American ones never showed up, and the British one I got died seconds after I plugged it in. Now I have European one, and it works great (even if I have to use a step-up transformer with it). In any case, the computer works! I installed a Gotek, and finally figured out how to set up my flash drive. But I've run into one problem. When trying to load the C64 emulator, it tells me I need to write protect the disk. So, how do I do that? Also, at the moment, I'm limited in displays. I've been using a composite, and it works fine, but I'd like to see some color at some point. Any recommendations for adaptors? Most of my displays are composite, VGA, and/or HDMI, but a few have component capability as well. Would I On joysticks/Controllers: Can I use a Genesis/Mega Drive or Master System controller? Are there specific controllers I should avoid? I have a tank-mouse. So I'm good on that end.

So like the title says, BBC Micro, Issue 4, Model B. At the moment, I'm still in the process of fixing the power supply, as the seller was kind enough to inform me that it failed a smoke test before he sold it. As such, I've replaced the two RIFA caps, and removed the third electrolytic recommended. However, two of the 250v 100uf capacitors were bulging on top, and discovered some slight leakage after I removed them. I have some 450v replacements that might/should work. I'm in the States, so I've been considering converting it to 115v, but I have a 250v step-up converter, so it's not a priority. Overall, the computer is in pretty fair shape. It was missing all its case screws but I found some suitable replacements. However, the vinyl on top is cracking and chipped along the right side of the keyboard and the user-ROM slot has been punched out. Question one: Is there anyone who makes a suitable replacement? I could fashion one, but I'd lose the labeling for the lights. Inside it has a Sidewise board (not entirely sure what's on it) which is attached to two switches on the back. Which leads to my second question: Would the Sidewise interfere with the User-ROM? I was considering adding a ZIF Socket (to plug the hole if nothing else), but I wanted to know how functional that would be? I've also seen an edge connector? Seriously, what would that be for? Additionally, there's a spot below the keyboard that I've seen some people (pictures and YouTube videos) where people added dip switches but they never explained why? Also, there's what I'm guessing is a double-density(or 2-sided) floppy board installed. But I know how proprietary the drives are? If I could get the right connector, could I adapt a standard PC drive? I also have a drive for a TRS-80 and Apple II, though I doubt that the latter would work. At some point I was going to get an SD solution, but floppies can be fun too. My next question regards ECONET. At the moment, my computer doesn't have it installed, but I was thinking of adding it. But what are the advantages and limitations? Can I use it to network to other 8-bit micros? Or am I limited to other BBC's? Can I use it to connect to outside servers? I understand these things can still connect to the BBC News feeds, but I'm not sure what I would need to do it? Lastly, is there anything else I should be looking into? Games? Accessories? Upgrades? Other add-ons that might be fun to play with? Any advice would be appreciated!

Interesting. Also explains something. The board's marked "OMIKRON MAPPER II," which Google says is a CP/M mod. But the board Google shows doesn't match what I have. (Better Pictures of my board below) Looking at it closer, it appears to be connected to the board in three places, none of which seem to be permanent (Clip to pin 14 on Z27, the edge connector, the socket). Side question: If I do choose to remove this, what goes in the original socket? Then why is it connected to a 25 pin port? If this is an RS-323 port ( as I originally thought) then I thought I needed an additional board in the upper compartment, but there's nothing in there. Instead it seems to be soldered to the pins where the edge connector is. As you can see, the wiring isn't that great as one of the connections has come loose. Also, because of the stiff wires used, the port only mounts properly over the Disk connector. So not a great place. Anywhere else and the sticks out at odd angles or comes in direct contact with the main board. If it is a lowercase mod, as you suggested, then it's redundant, since I already have unit with an electric pencil mod. You seem to have it right. All three, bricks and outlet have been spliced into the same mains-in. The wire they used matches what would have been used for the original plugs on the bricks. However, the plug they used (the part that would go from the wall to the three way split) is non-polarized. The other issue is that one of the bricks shows clear signs that someone tried (unsuccessfully) to get in it. It makes me wonder if something may have gone wrong, or they just didn't like the looks of it? For the most part, I AGREE! Most of the wires used are far too long and way too stiff, making cable management a real pain to deal with. However, if there is any benefit to these mods, then I might try to clean them up instead. For instance, if the (possible) data separator board really improves disk performance, then I might want to keep it. On the other hand, if it is a CP/M card, then out it goes. Especially if it interferes with me plying Frogger! Side note: I would like to now what that port does (or was supposed to do, if anything). As for the power supplies, I'm probably going to replace those regardless. For the moment, I have two functioning bricks, and I understand that there is a new single plug option that can be safely mounted internally. So I'll probably look into that. If it's really safe then I'll wire that extra power outlet into the mains before new PSU. Maybe I should be adding a fuse into the mix just to be safe. I may also look at the bricks and see if either of them are salvageable. As I said, I have two working bricks, but three working Model I's, and now an Expansion Interface. So having enough power supplies for each would be nice. But whatever I do, it's not going to be held together by electrical tape.

Like the title says, modded TRS-80 Expansion Module. The first I was told to be a CP/M mod connected to what looks like an RS-323 port via a floating pcb. It's attached to an edge-connector by a single wire (I'm assuming to tap voltage from one of the pins). There are several several wires soldered to the main board so I'm guessing it's not easily removable. I'm not too worried about it. Still, I'm wondering if this will interfere with running regular TRS-80 software as I don't have too much use for CP/M? The second mod is more concerning. It looks like the original owner connected the two power bricks at the mains and spliced off to a two prong outlet on the back of the Module. My guess is that they were trying to reduce the number of plugs they needed. The two bricks would power off a single line with the monitor plugging into the additional outlet on the back. However, I'm not sure this is safe. I know that there is a PSU upgrade that can power both the computer and the Expansion Module, but I've never heard of anyone trying to add a monitor outlet on top of that. When all was said and done, the two bricks were hanging outside of the case. My guess is that whoever it was couldn't figure out how to fit them in with all the wires. It also appears that they tried to pry their way into one of the bricks (probably to reverse the mod and attach a new mains plug). Also, none of this is earth grounded, and the splicing is covered in electrical tape. It took some doing, but I did manage to fit everything inside. With a few zip-ties, it might even be tidy. But before I do, I want to make sure this isn't going to blow a fuse or burn my home down.