Jump to content

DistantStar001

Members
  • Content Count

    390
  • Joined

  • Last visited

Community Reputation

70 Excellent

About DistantStar001

  • Rank
    Moonsweeper

Profile Information

  • Gender
    Male
  • Location
    San Rafael, California

Recent Profile Visitors

2,945 profile views
  1. 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
  2. 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.
  3. 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. 🙂
  4. 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?
  5. 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?
  6. 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.
  7. 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.
  8. 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.
  9. I just got a TRS-80 Model I, and I wanted to know if there was anything I should be aware of before I power it up? So far, the only accessories I have for it are two original power supplies (untested at the moment, but I'm going to check them as soon as I find my multimeter) and a home made cassette cable that works great with my CoCos, but not my Model III. I've already looked up how to splice together a composite video cable, and from what I can see it has a level 2 ROM update. Some initial questions: What's the story on the original power supplies? I know that Atari (XL/XE) and Commodore bricks are system killers waiting to happen, but what about the TRS-80? What would be the best source for cassette (.wav) software? Related to above: Any recommendations for games or software? Anything I'm forgetting? Or any other recommendations that would improve or help preserve this machine? Discovered a broken standoff in side, and this modification. Curious if anyone knows what it could be? Also, what's the best way to repair the plastics? Also seems to be a reset switch. Is that normal?
  10. There's a jumper in that location that the penny seems to be sitting on top of. Maybe they ran out of wire? Wouldn't be my preferred method of repair though, as the penny could make unwanted or even hazardous contact with several nearby components.
  11. Check the electrolytic capacitors as well. I had assumed that the rust was the result of a bad clock battery since what I could see of the analog board looked fine, but having a second look, and the power issues, tells me that there might be some leaking going on as well. I'd have to see the entire board to be sure. Console5 sells a kit with all the capacitors you'll need for about $20: https://console5.com/store/macintosh-128k-512k-plus-analog-pcb-cap-kit-630-0102-661-0462.html Also, you might consider scrubbing the corrosion off the metal frame with some vinegar, salt, and a wire brush. It's just not good to have that in contact with the boards.
  12. From the picture of your motherboard, it's definitely a Mac Plus. It was likely a 512k once, but it's been upgraded. You can see the 8-pin round serial and 25 pin (D) SCSI ports. The 512 and 128k used 9 D styled serial ports and lacked SCSI support all together. Instead they used custom hard drives that interfaced through the 19 pin floppy connector.
×
×
  • Create New...