DistantStar001

Thanks! 9334 it was! It's been a very happy machine since it was replaced!

New problem. The power supply blew! Bad RIFA. Popped, spit smoke, no -5v on board. Sadly, I'm going to have to go over it before I can proceed further.

The garbage screen is back, and I still don't know why??? I've tried every socketed RAM chip on the board in an Apple ][ Plus and every chip tested good. So... not the RAM? There were several ICs with corroded legs that I replaced, but there has been no change in behavior. I'm starting to turn my attention to the sockets themselves. I had sprayed them all with contact cleaner before it came back to life, but maybe there's some oxidation or corrosion that I missed? It would make sense if the chips were corroded that the sockets would be too, but the thing is, none of the RAM is corroded, only a handful of logic ICs. I don't know. It might explain why rearranging the RAM temporarily brought the computer back to life? Any suggestions?

Thanks, but did you mean the 9334 at F14? Because I'm not finding a 9331 on the board.

I have a 48k Apple ][+ with a Z80 and ROM switch card (with original Apple ][ ROMs installed on the card), however, I do not have a language card at the moment. The computer works for the most part, but every so often, it gives me some graphical glitches. It's usually fine for the first hour or so, but after a while, it would lose horizontal sync when I hit certain keys (mostly the space bar). The effects were temporary at first, but eventually, the picture would cut out completely or come back with random characters on the screen. Either way, the computer would be nonresponsive for about 5 minutes or so, then come back after power cycle. The keyboard had been problematic from the beginning (shift and other keys would cut out after prolonged use, sometimes the reset key as well), but I couldn't rule out a loose or dirty connection to the PSU (the machine was pretty gross when I got it). When I first got it, I got no picture and no beep. I washed the motherboard and cleaned out about a dozen pine needles from in between the sockets and slots. I also scrubbed out some light corrosion in the area between rows C and D, as well as in slot 0. Replaced multiple ICs (not necessarily damaged, but chip swapping to diagnose a Franklin ACE and fix the no picture issue that might have been the unadjusted potentiometer at J14) and the socket at C2. Long story short, eventually, it came back to life. So I sprayed some more contact cleaner into the power connector and reflowed all the solder joints on the keyboard. I also fixed some dry sockets on the connector to the encoder board, which seemed to resolve that problem (for now). The 4 and 7 keys are a bit stubborn now, but overall, it's an improvement. But now, every so often it's flashing a Garbage screen when I use CP/M? It doesn't seem to interfere with operation like the previous glitch did, but I'd still like to try and fix it before it becomes a serious problem. I'd love to find some good diagnostic software. I tried Apple // Diagnostics, but I keep getting an "unable to load ProDOS" error. MECC Computer Inspector works, and I've tried Apple][ RAM test but all they seem capable of telling me is that the RAM is OK. Everything else I've found has been for the //e or //c, but they've also been far more informative with those systems than what I have for the ][+. Any suggestions? Update: Garbage screen is flashing in BASIC as well. I got a better look at it, and it appears to be the same ? and inverted @ monitor boot screen from the ROM switch card? The thing's off, so it shouldn't be doing that.

Fixed! The pins on the encoder board were dirty.

Recently, I got an Apple ][ Plus in externally decent condition, but internally not so great (lots of dirt and debris, some corrosion on the motherboard). I've replaced the motherboard (tested to work, and boots). The old motherboard has no video signal whatsoever, no beep (did beep for a bit, but then stopped). Unfortunately, the Keyboard had been plugged into it backward (something that I didn't realize until I tried using it as a guide on the new motherboard). The new board still boots. But most of the keys didn't work (mostly the letters). Long story short, I ended up replacing both 74LS00s and the 74LS04 on the encoder board, as well as both 74LS257s at B6 and B7, along with the 74LS74 at B10. Tested the switches (all good), and replaced the ribbon cable (broken pin). Things were better after that, but there were still some keys that were nonresponsive. Then I noticed that the power light was cutting out when the ribbon cable was jostled, so I added some sockets in between the cable and the boards to give it a tighter fit. Now everything works except the Shift keys? I should note that the Shift keys did work for a moment when I swapped back the old 74LS74, but others didn't. I don't think the IC had anything to do with it, as several keys were nonresponsive, but all the functioning keys were working fine (including Shift). I did try swapping them back, but it didn't bring back the Shift key, while the other keys that were nonresponsive remained nonresponsive. I'm guessing that it's still a cable issue, but in case I'm wrong, maybe someone knows any other IC failures that could cause this issue? Alternatively, if it is the cable (made it myself, so entirely possible), maybe someone could tell me which pin is responsible for the shift keys? At the moment, the only source I have for a new cable would have the same loose pin issues, so if I can figure out which pin, maybe I can address the issue until I can make a new one with better parts.

It's working now. No idea why. Still need to fix the keyboard. All of the come pads have deteriorated, so they'll need to be replaced. Does anyone know where I can find them?

Update: On advice from Applefritter and 68kMLA, I tried swapping RAM chips between rows. The machine booted after swapping the first chip! Then, after repeated testing, it went right back to what it was doing before. Weirdly, the first chip I swapped looked to be Apple-branded. Don't know if this is important, but all the RAM chips are ceramic cases, and the one at F6 is soldered to the board. It's literally the only IC that is (has me wondering about the sockets). I ended up swapping every chip with the first row (except the one soldered into F6 obviously) with no success. So at this point, this has become a tale of two computers. Not making any progress with the RAM, I tried swapping chips between the Apple ][ Plus and the Franklin, trying to see if the no video/no beep would follow a damaged chip. I ended up swapping the 74S86 (B2), and transplanting (as several of the legs from the Frankin ICs snapped right off as soon as they left the sockets) the 74S175 (B1), 74LS153 (C1), 74S195 (C2), with no change in the Franklin's behavior. (Side note, I knew this thing was a clone, but I had no idea just how much of it was copy and paste.) At this point, according to the Sam's guide, IC failure is not my ][ Plus's problem. I still have to get replacements for B1, C1, and C2 anyway as I have two computers that need them, and now only enough chips for one. I suppose I'll try swapping the RAM from the ][ Plus to the Franklin? I still don't know if that bodge wire on the Franklin board is normal or not, but it doesn't seem to be interfering with operation, so I guess I'll leave it. Also, now I know that the keyboard is nonresponsive. So progress! Still, if anyone has any ideas...

Just picked up a Franklin ACE 1000 and I have an issue. The computer powers with a screen full of garbage (various random characters, many inverted, with a few random solid and checkered blocks mixed in), and will beep on power-up most of the time (every so often it's silent). Usually hitting reset will cause it to beep, and typically change the garbage on screen (fewer characters, or more spaces, lots of exclamation points). So far I haven't done much to it. Cleaned it out. Removed something like a dozen acorns from inside. I didn't see or smell any evidence of something living in there, and some of the actors were too large to fit through the slots in the back. I can only conclude that someone did that intentionally. I just can't figure out why. I also opened the PSU to check the REFAs and tested the voltages (they seem good). Removed the two cards (a Microtek parallel printer card and a Franklin disk controller). I should note that with the disk controller installed, there is no beep at all, and the garbage on the screen consists of blocks and patterns. I got a similar result out of an Apple ROM card with Integer BASIC. That's about it. Beyond that, I really don't know what I'm doing with this. While I do own several Apple IIs, up till this week, the oldest was a //e, which is a very different animal (even if largely compatible). I now have an Apple ][ Plus as well, but currently it's in worse shape as it neither beeps nor gives a picture. I may post about that later if replacing the 74S86 doesn't help. For now, I've been going through Sam's Troubleshooting guide (how I knew about the 74S86), but I'm not sure how much of this will translate? Does anyone know of a troubleshooting guide specifically for the Franklin? Or have some idea where I should be looking? Any help would be appreciated. Below is a photo of the motherboard. There's a strange jumper wire that runs from the IC at B12 all the way to R62 [missing] at A14. I'm not sure if that's normal or not. Also, there are two screenshots, the first is of the initial power-up, the second is after I hit reset.

OK! Figured it out. It was the 558 all along! I could have sworn that I tested it in another board, but I guess not. Anyway, Thanks for the help.

Any idea where I could find that? Specifically relating to the joystick port? I've found several online, but those seem to be for the logic, and don't specify the port. So far, all I've been able to determine is that pin 5 is for the X axis. I'm probably going to try and trace the pin on the board itself through any passive components to see if one failed. The relevant schematic might make that search easier. I've also looked at the SAM's Apple II/IIe Troubleshooting & Repair Guide, but all that was able to tell me is that it's not an IC problem (swapped all the related chips with no effect).

Overall, the computer boots, loads programs, passes self-test, and performs very well, but with one small exception. The joystick (a 9-pin CH Mach III I believe) isn't being recognized properly. The board has had some (rather sloppy) work done to it. All of the RAM sockets, as well as the sockets for the EF-ROM and the S02 chip, have been replaced. Some of the traces from the RAM chip at F6 are broken, there are a number of bodge wires in their place. Also, one pin seems to be free floating. However, I've checked all the connections, and everything seems to be connected. Also, as mentioned, the computer is more or less fully functional now! All and all, given everything that has been done to this board, I'm taking an "if it ain't broke, don't fix it" attitude to this. However, the joystick is the one lingering issue I have. I've tested both the stick and a set of Apple-branded paddles on this board, as well as on 3 other working //e's and a //c. Both work perfectly with the other 4 computers, but not this board. MECC Computer Inspector isn't recognizing anything connected to the port (I also tried a 16-pin Mach III as well). In games (Centipede, Star Trek SOS), the stick automatically goes to the lower-right corner but the games do respond to input from the stick (up, left, down, fire). When tested on the other computers, MECC Computer Inspector reads the stick as slightly off-center (jumps back and forth by a pixel or so every 15 to 20 seconds) but it's not enough to affect gameplay. So, at this point, I'm pretty sure that it's not the joystick. I suppose I could just accept that this thing won't be a gaming machine... But then, this thing is so close to being fully functional, why give up now? If anyone has any ideas, it would be very much appreciated.

So I got a 48k Spectrum (Issue 3B) some years back and while for the most part, it works, it always had a lousy picture (noticeable vertical bars in the main field and diagonal wavy lines on the bottom). Basically, it needed a recap (also it was starting to randomly crash). So I recapped it. As near as I can tell, the system seems mostly good now. It boots more or less reliably (occasional glitch, but far less than before), no longer crashes, and the video artifacts from before the recap have more or less gone away. However, the colors are way off? In testing the machine (I used the BASIC Border command), blue is black, green and cyan are indistinguishable from one and other (as are red and magenta), and yellow is light pink? For info, I am in the United States, so this has been composite modded with a 100µf capacitor bypass to the RF, and I have been using both a Sharp Aquos LCD and a TCL 41in 4k LED TV as a monitor. Both TVs worked perfectly with the spectrum before the recap, as well as my PAL C64. Both have been tested with my PAL C64 since and give a perfect picture. I've gone over this a dozen times. All caps appear to have the correct µf values (voltage ratings are rather high [some as high as 50v for what should be 10v], but I was told that shouldn't matter?) and are installed in the correct orientation (I don't think it would boot at all if they weren't). I used the kit from Console5 which is supposed to be correct for my revision. Any ideas as to what I'm obviously missing?

Personally, I would just use DriveWire for this. You will need a working Coco (sadly not the MC-10), and a cassette cable to load HDB-DOS, and a DriveWire cable with a 9-pin serial to USB adapter to transfer files between the Coco and your modern computer, but once you have them, it's pretty easy (if a bit roundabout). Basically, once you have everything set up, and loaded HDB-DOS, you will (first) 'insert' a disk image you don't mind overwriting (best to make a copy of something and label it BLANK for future use) into device 0 in DriveWire on the PC side of things. (Note: on DriveWire, the virtual 'drives' are really 'virtual devices' representing about 250 or so 'virtual floppy drives'. So stick to Device 0, and ignore Devices 1-3. It saves a lot of confusion and frustration, and I'm not sure you can copy disks between devices in any case.) Second, type "DRIVE OFF" on the Coco and hit Enter. This tells the Coco to access the physical drives for drives 0-3 on 'device 0'. Everything beyond that (4 and up) will be virtual drives you can use for backup. Third, insert the disk you want to backup into your physical floppy drive (usually physical drive 0), and type "BACKUP 0 TO 4" on the Coco and hit Enter. Your Coco and DriveWire should then make the virtual backup in drive 4, however to save this backup to a file you can access and archive, you will need to save the image back to virtual drive 0 as that's where your destination image is. To do this, type "DRIVE ON" on the Coco and hit Enter, once again addressing drives 0-3 as virtual. Then type "BACKUP 4 TO 0" and hit Enter on the Coco (it's important to use 0 as the final destination to save your file). DriveWire will save the backup to the disk image. After that, 'eject' the disk image from DriveWire and re-name the file. That's it! You're done! To make a drive wire cable you will need a male 4-pin DIN, and 9-pin female D connecter and appropriate 4 wire cable. Personally, I used an old Ethernet cable, but snipping both ends off of an USB will work as well. Then simply follow the instructions on this website: https://www.cocopedia.com/wiki/index.php/How_to_build_a_DriveWire_serial_cable

The title pretty much sums it up... I have a Model III with disk drives and a hand full of floppies I got from TRS-80.com, including a few game disks they had been generous enough to include. Unfortunately, I accidentally zapped my favorite game disk (Wayne Westmoreland), and it's been dodgy ever since. Sadly, I hadn't figured out how to make a backup at the time, so now I need to replace it, but I don't know how. Also, there are some other programs and games that I would love to put on a disk, so I would really like to figure this out. I do have a 486 PC, but the instructions to write disks that I've found have always been a little vague. I still don't know how to map an emulated drive to the B drive, nor have I found a suitable 180k disk image to work with. I watched the video on this from Adrian's Digital Basement, and he suggested a NewDOS/80 image, but none of the ones I've found match the needed file size. And long story short, I've been hitting my head over this for more than a year now, with no success. (Side note, I've also been having similar trouble using it to write Atari 8-bit disks as well. So there may be other issues with my setup that I haven't figured out yet) Then it occurred to me that there might be a simpler solution if I can use the DriveWire setup for my Coco 2 to write disks for the Model III? To my knowledge, the physical floppy drives are interchangeable, and I can hook my Coco floppy drive directly to the disk controller of my Model III... So maybe the two machines use the same disk format? If so, is there a program that would allow me to make copies of a Model III or Model I disk with my Coco? Alternatively, could there be a program that would allow me to transfer cmd or bas files onto a Model III disk through DriveWire? They're both Radio Shack computers, so I have to imagine that someone has addressed these cross compatiblity issues before? I'd ask if there's a program similar to DriveWire for the Model III, but I don't have a networking card for it. So for the time being, even if it does exist, it's probably a nonstarter for the moment. At least until I can find one (and work up the courage to disassemble my Model III to install it), or alternatively, find an Expansion Interface for my Model I, then that would be helpful. But for now, I'm stuck with the hardware I've got. In any case, I'd love to know if this is possible? Or alternatively, a better idea on how to get my 486 to work? Or an archive of TRS-80 disks in .wav format, similar to the Apple II Disk Server? Anything that will finally let me start making some disks? Any help is greatly appreciated.

OK, so I've managed to get my Model I fully operational, and have collected a little under 30 games for it so far (.wav files that I hope to put onto real cassettes eventually), but I can't seem to find the one game that I really want, Tetris... As near as I can tell, a version was released on disk for the Model 4, but that doesn't do me any good as all I have are the afore mentioned Model I and a Model III. It seems strange as Tetris is such a simple and popular game that can run on far less capable hardware. I mean, I already have a port for my 1K ZX81, so I have to believe that someone out there has made a port of it for a 16K Model I? If anyone can steer me in the right direction it would be appreciated. ?

I've been working with a C64 motherboard (Rev. 250407) that has developed some issues. At some point, it just stopped giving a picture. Not a black screen, just no video signal at all. At first, I thought it was the ICs responsible for the timing circuitry, so I replaced them with no change. Then I noticed a broken trace on the back (not sure if it was there before or after I replaced the ICs, but once patched, I get video again. Unfortunately, all I'm getting is a black screen. The VIC II has tested good in other machines, the SID has been removed (but not tested yet), the PLA is PLAnkton replacement and is working to the best of my knowledge, all other ICs are soldered into the board at the moment, so I haven't been able to individually test. Even so, I think they're fine. Obviously, I can't be sure, but the 5v DC rail that feeds into the ICs is good. The voltages that come off of the 9v AC rail are another story. The output on the Bridge Rectifier is only 5.72v (compared to 8.2v on one of my working C64s with the same board revision), which is what I'm also getting on the input of the 7805. The output, however, is only 3.2v. The 7812 doesn't seem to have a problem and is putting out 12v even. This tells me that the VIC II isn't getting the right voltages, which is preventing the computer from booting. The PSU is from Ray Carlson and works perfectly with at least five other C64s. So I think I can safely eliminate it as a potential source of my problem. I have also swapped out the 7805, and large capacitors with no change. I'm leaning towards the rectifier as the culprit, as it's the next thing up the line and directly connected to the switch, but wanted to know if there were any other components that could be an issue?

Fixed!!! It was bad solder joints.

Update: So (thanks in no small part to the folks over at the VCFed.org) I've managed to repair the video issue! The working theory is that someone plugged a power supply into the video port and fried the ICs at Z5 and Z6. I've replaced them, and now I'm getting a good picture. Unfortunately, the Keyboard is another issue... I've tried paper, cardboard, Isopropyl alcohol, and DeoxIT, and so far the best I can do is get the key back for a few minutes, then as soon as it drys out, the key stops responding again. I did manage to get the "*:" key back to a reliable state, but then the ">." key went out. The mechanisms are the same as the ones on my Ti-99/4A (which was a pain in its own right), but this is being especially stubborn. The "0" key is now completely unresponsive, but the "/?" key is the most concerning, as, without it, I can't run a machine language program. I will admit that this computer was especially dirty when I got it (tons of dust and grime with a few creepy crawlies that breathed their last inside), but the contacts look clean. Still, I'm starting to wonder if it's time to try something more aggressive? Does anyone have any ideas as to how I can get the more stubborn keys going again?

Ok. I may have stumbled upon something. The 3904 transistor has about 4.9v at the collector, but 0.02v at the emitter? I think it's Q1.

Yes, as pictured above.

Yes. This is the exact video I used to make my cable. Yes I get a red light. The good news is that I have a multimeter and two scopes! The bad news is that neither of my scopes are working... But I do have a logic probe if that's helpful?!? It's a bit wonky (red is high, green is low for some reason), but it works. Can't hurt to try. Working with what I've got, I've checked the voltages on the RAM and processor... The 12v line is spot on, the -5v is coming in at -5.12v, and the +5v is a touch low at 4.93v. I tested the video out, and I'm getting practically nothing. About 0.01v. If I'm not mistaken, I should get at least 1v on a composite signal? At least that's what I get off of my VIC-20. Moving on to the logic probe, I'm getting activity from the RAM and processor, so I think the computer is actually doing something, even if I can't see it on my screen. This is the readout on the pins so far: Z-80 Pins 1: No Activity 2-10: Flashing 11: High 12: No Activity 13-20: High 21-25: High 26-27: Flashing 28: High 29: No Activity 30-35: High 36: No Activity 37-40: Flashing 4116 RAM Pins 1: No Activity 2-7: High 8: not tested as it's 12v 9: No Activity 10-15: Flashing 16: High I'm also including some pictures of the board, as there appear to be several modifications, and I don't know enough to say that they're normal. As you can see there are several areas where the mods were wired in from the back and some bodges. The soldering is clean, and whoever did it seemed to have known what they were doing (from a soldering perspective), but I'm not sure how these effect operation.

OK, so not getting a video signal.

Thank you!!! And also... Sorry about that. I took the picture and forgot to add it! Also, I do have one question about the video cable. I know that the original monitor powered off the computers port and I'm concerned about shorting the power into the composite. Should I clip that pin to be safe, or am I being overly cautious? I've never had a machine this old, so I really don't want to hurt it.