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Another thing you can try is starting it up in 64 mode. Hold the Commodore key on power on. Sams Computerfacts has troubleshooting info for no video, but it requires a multimeter and o-scope. You may want to look here and download some repair manuals: http://www.bombjack.org/commodore/books-commodore128.htm Unfortunately the 128 is more complicated than the 64 for repair work since it's 3 computers in one. The Z80 CPU in the 128 is actually part of the power up sequence so if it's bad, you'll get nothing out of it. But it's odd you would have 3 128's with the same issue. I know on a 64 bad RAM will cause a black screen. You can usually test for that using a cartridge like radar rat race that bypasses the RAM. Any Ultimax mode cartridge will do. If you use a 64/128 a lot, you can always invest in a dead test cartridge and also a diagnostic harness/cartridge. This helps with troubleshooting issues (including no video (w/ dead test cartridge) ) greatly. From Sams Computerfact for the 128: "No video when using the RF modulator. Use a scope to check for a video waveform at pin 17 of IC U21 (this is the VIC). If the waveform is missing at pin 17 of IC U21, check IC U21 by substitution." Looks like you've posted about this on lemon64.com too. Seems we should try our efforts on one site instead of 3.

There is also the emulators and development tools by Matthew Reed: http://www.trs-80emulators.com/#DevelopmentTools While there is no IDE for it like Eclipse, you can just use your favorite text editor or something to build your source. Only the registered version allows you to interact directly with virtual disk files, however, his TRStools software allows you to insert files, create virtual disks etc.. so the limitation isn't that bad to me. I went ahead and licensed my copy though. I wanted to encourage him to continue to make and support this software. www.trs-80emulators.com/

Hi, I'm glad you were able to get your Model III working 100%, that is great news! I'm sure you've seen these 2 items, but I'll share them here anyway. I'll say up front, these are not super cheap. First, there is the FreHD: http://ianmav.customer.netspace.net.au/trs80/emulator For FreHD, Ian sends along 2 (1 for boot 1 for backup) floppies that you boot from to start up the FreHD and then once it boots, you can remove the disk from the real drive. He sells (or you can burn your own) a ROM that will allow you to boot without a floppy, but I have no experience with that. You can place disk images from the internet onto the SD card and copy them back to real floppies. Second, there is the M3SE http://bartlettlabs.com/ The creator of this item sells them on eBay along with the Model 1 version (MISE) http://www.ebay.com/itm/222018785069 (you may be able to get a few bucks off if you buy direct from the seller outside of eBay) I don't have the Model III/4 version, so I can't speak about that, but the Model 1 version boots without a real floppy in the drive and then you can also copy disks back to the real floppy drives if you wish. Maybe someone else can recommend cheaper options.

This is fantastic! I love to look at how these games were made. Thank you Russ and Savetz.

Great! I really hope you can get it working again. I have a Model 4 myself, but I really love the look of the III and 4. Just remember to be very careful when you pull the case apart so you don't catch the back of the picture tube on the housing for the PCBs. But sounds like you have already pulled yours off, so you are probably aware of that. I think the older Model IIIs came with 2 power supplies if they had the disk drives, but I don't claim to be a TRS-80 expert. Good luck.

Hi, there are 3 capacitors that usually need to be replaced on the power supplies of the Model 3 & 4. Check out this video He is a fellow from Australia that repairs and sells parts for the TRS-80. The non-working drives could also be a bad FDC or possible the ribbon cable that connects the PCBs. You could also email Ian directly for advice http://ianmav.customer.netspace.net.au/trs80/

Yeah, I'm still on the 2.6 series. I haven't tried the beta versions of 3.x yet.

Hey Larry, well, I personally like and use the XRGB-mini Framemeister. But it's a little pricey, we are talking over $320 US. It even allows you to add scanlines I don't use it daily though since I still have working CRTs, it was mainly to use when the CRTs fail. It can even do RGB with the right connectors. Here is one on Amazon.com: http://www.amazon.com/DP3913547-Framemeister-Micomsoft-Upscaler-Japan/dp/B00QUBK6RK/

Well we made it! I can't wait for my new Amiga 1200 cases. Thanks Phil!

Cool, I didn't know about "Penetrator" until now. It looks pretty nice! I'll have to download it for my real TRS-80. My time with the TRS-80 was mostly about BASIC programming and had very little exposure to games on it. If I remember correctly, we only had "Cosmic Fighter" on tape in my school.

I'll check back to see what you come up with. We've already helped out at least one other person (that we know of) besides me with this project, so that is cool! Thanks again for the assistance you have provided getting me this far.

Awesome! Glad it helped you out. I was really happy to get mine working too after sitting in a box for a long time.

Hi 1050, well, you certainly have a better grasp of what is going on than me. As far as room, there isn't much room between this board and the next RAM module really. The chips ride pretty high when they are inserted into the PCB. I'm attaching a picture of the back side of the board. The FP math ROM is the 3rd from the right side (looking at the back). At this point, if it's going to take a lot of jumper wires or modifications, I really don't think it's worth the effort to me though. The board works now as it is with OSN, the Stock Atari FP math package and Omnimon. That really is good enough for me.

Nice, thanks! That makes it easier for folks.

Not sure if anyone wants this. I've scanned the Newell RAMROD MMOS documents. I apologize for the indvidual PDF files. I couldn't figure out how to get them all in one Update: Allan was kind enough to upload the document to atarimania.com: http://www.atarimania.com/documents-atari-400-800-xl-xe-manuals_2_8.html I'll be removing this upload eventually to save on space. RAMROD MMOS.zip

Thanks for the effort. I'm sure there will be others in the future attempting this as well. I'm uploading the RAMROD MMOS document as well in case someone wants it (posted in another thread).

No, didn't work. I get a green screen when I try to use it.

Hi 1050, OK, so this would test (in theory) if an eprom can replace the stock FP package?

My CMOS 27C16's came in today, I programmed them with the FastChip.rom and still nothing! When I use the stock FP ROM, everything works as is expected though. While searching for information on the Fast Chip I read a thread stating that the math package is a custom masked ROM. So I guess there is no use in attempting to swap an eprom for it. The stock OS math package is probably that same custom mask ROM. I don't know. I will quite while I'm ahead. At least I have OSN now and Omnimon on my 800. I will just buy an OSNXL from B&C and put it into my 800XL At least then I know I have all 3, OSN, FastChip and Omnimon.

Hi Larry, thanks for the tip! I can't say I really looked at the legs on them before I attempted the programming. I did order a batch of CMOS 27C16s as well so maybe the 2 NMOS '77 EPROMs I have are not good. Since this is the first time I've ever tried to do this, I was super excited when I found that the OmniMon worked as expected

Yeah, OSN is the Newell RAMROD OS. I didn't try the FastChip rom using the stock OS ROMs, so I can give that a shot. It could be possible both of my 2716s (I only have 2) are bad. They are dated '77 but it programmed without an issue in this last run. They both are in great looking condition for 1977 EPROMs and are supposed to be NOS.

Thanks, yeah, excited to finally get some use from this board! I played some Pac Man on it with the cartridge from Tep392. This should prove the OSN is working shouldn't it? The lack of the "Atari Computer - Memo Pad" on first power on has me concerned, but it may be normal for OSN. Doesn't appear to be much information out there on OSN that I can find. I also need to figure out why the FastChip.rom provided by 1050 doesn't work. Maybe I'm doing something wrong with it during programming. I appreciate the assistance and guidance everyone has provided while I worked my way through this.

Fantastic! OmniMon provided by 1050 in this thread works just fine! I used one of the extra 2732 ROMs I had, placed it into the RAMROD and started it by holding OPTION and hitting SYSTEM RESET. AtariGeezer, I did find a "Blank Check" option and it showed the chip was empty, but then I tried to program it and it still failed. I tried another, and it worked. Go figure.

My first attemp with FastChip.rom didn't work. Should I have specified an offset or just let it burn with the defaults? I used a 2716 EPROM for it. I'm going to try the OmniMon now and see if that works.

Ah, OK. I'll have to take a closer look then. I was kind of excited to get cracking on this! This second attempt seems to have faired much better, no failures this time after the UV erase run. I've discovered 2 things: 1) OSN doesn't appear to have that "Atari Memo Pad" screen? 2) The FastChip.rom in this thread doesn't seem to work. When I put the stock math ROM on the RAMROD with the 2 OSN ROMs I'm able to use the BASIC cartridge and play Star Raiders. But the math ROM I created, no joy. Does this mean my OSN ROMs are working? I'm not really sure at this point One point to note if anyone is going this route, you'll need the external power supply for the GQ-4X to burn the ROMs. The software actually tells you as well when you select the chip type.