Do not bend the Eprom pin, it will break when you need to bend it again. Instead, plug the eprom into another external socket, and bend the socket pin to fit the programmer's socket.
If you want to do it many times, then it's a good advice. Thank you. However, if you need to do it once, it's ok, just do it slowly. This was not the first pin I bent ;)
Necroware, thank's for sharing this info and all the guy's that comment it. I have a problem trying to copy a tms27c64 eprom from a machine that is still working at my place of work. I managed to buy two new m27c64af and now watching this video of yours, it made light, I already understood why the first one I recorded doesn't work. Now I'm going to test it with the other one to see if it works. Ah, the programmer I'm using is the tl866II with the latest update from the manufacturer's website. Thank you very much for this explanation and I will keep you posted. Keep up your videos, I've learned a lot from them.
Thanks for the precious hint: I guessed a similar option with my Hitachi 482764, and you confirmed and explained how to do it properly (it seems that most of N-MOS EPROMs need a Vpp of 21V or more ). Regarding bending the pin I just bent it only in the final part, not next to the main EPROM body: in this way I stressed it in a less dangerous place, and I managed to fix in place the remaining pins, even if the EPROM was slightly lifted on one side. Of course a ZIF adapter with optional external Vpp terminals or modifying with a switch the programmer itself would be better and more clean options.
Thank you! That was my guess when I thought about how to program GAL16v8 (for the MCE adapter) in Triton+ programmer (which doesn't support GALs but only ATFs).
Great work here! I have 2 videos from 2019 that show a very similar work-around that I also came up with. But your video is shorter, and more to the point (better produced), so thank you for sharing this! I would link my videos here for reference, but RU-vid will likely block my comment if I do. Just search RU-vid for "MiniPRO TL866 programming boost" and my videos are currently the top 2 hits for that search. Again, nicely done!!!!! I'm going to link YOUR video in my video description and pin comments, because I think viewers might appreciate it! Keep up the great work!
I recently ordered the TL866II - useful info, thanks. Maybe it would be a good idea to add a small capacitor (say 10-100uF elyt. + 100n ceramic) parallel to the VPP/GND pins if the wires going to the power supply are somewhat long, just to be sure.
Very good idea. I would cut the PCB trace to the ZIF socket. Install a tiny switch and small pin contact for external power. Very useful information. Tks.
I had a thought whilst watching this. You bent the pin of the chip up out of the socket, and sure it'll probably bend back ok the first time you do it, but what about the next time, or the time after that? If instead you put the chip into a socket, and then bent the appropriate leg of the socket before inserting that socket into the programmer you would avoid the wear & tear on the relevant chip pin.
This is an EPROM you program it once and usually never touch it again. It was more a question of throwing it away or to find a way how to program it once I need it. If I want something to play with reprogramming, I'd just take modern EEPROMs, because I don't want to wait 20 minutes each time to erase the EPROM.
Been doing this for a long time. If you actually probe the Vpp on other EPROMS while it's programming the unit rarely actually provides the correct voltage. Best bet is lift the pin and use an external power source. It's too bad they don't have an external power port on the TII burner.
Nice trick! :D I only have an old Willem parallel port programmer donated by a friend because he bought a better one. I dont know why lowered the voltage on TL866II+, was nice with the previous generations of this programmer, maybe could be sorted out some hack for it to output 21V ???
Hello Jorge! Some things were improved on TL866II+ compared to the other models and some features were dropped, like 21V Vdd support. I guess, all the 21V EPROMs are a dead technology and all the modern (E)EPROMs need much lower voltage to be programmed. However, this channel is named Necroware and it is somehow about dead hardware or things around this topic :) I think, that modifying TL866II+ is too much effort, since you not only will need to hack the hardware, but modify the firmware and the software too, because you can select voltage only there. I don't think it's worth it and will stick with this trick, if I need to program an IC with higher voltage from time to time. This doesn't happen that often anyway. Thanks for watching my videos once again! :)
I tried this with a 21V VPP vintage 8751 (not the 12.5V 87C51) but the chip burned - blue flash seen in the window when 21V was applied to the VPP pin resulting in a dead chip. Seems it doesn't work with microcontrollers as it does with EPROMS.
Hi friend, okay? I hope so... I had a 128 file, and I recorded it on a 256 eprom, but when I installed it on the equipment, it just didn't read... Then a friend said I wouldn't need to buy a 128 eprom , he said that he simply "mirrored" the 128 file to be recorded in the 256 eprom, sent me the file, recorded it, and it worked! But he didn't use Xgpro (which I use) for that... How would I do that using Xgpro? I use the TL866II recorder...
You don't need to mirror it, you just need to checkout what happens. Obviously the device, where you put the XTIDE BIOS into starts to read the data at 16K offset. This means that the highest address bit is always 1. So you just need to write the data into the second half of your EPROM. In the TL866II software, when you load the ROM image, you can set the offset address. You just have to set up the second half that would be at 4000h. You can also load multiple times and give different offsets every time to combine. You always should zero the data you don't need.
Good idea. I have model TL866A what's the difference? I hope the programmer will not get damaged with the external 21V supply. It seems not as you've already tried it. Thank you.
Dear question, I have an EEPROM memory with a specific number that I could not find in the market. The memory size is 256 KB. Can it be replaced with another? It does not. have to be the same number, but of course the same size, or it must be the same number and the same size. The one is damaged is one time only read memory"TMS27PC256-20NL". The one i will used is UV EPROM"M87C257-20F1". With same size of course i will transfer data with programmer from TM to M8. Can do that because idont have TM eprom. I have M8 eprom.
Thank you! GALs, PALs, PLDs are not the same as EPROM. They are not programmed by setting VPP, but by issuing special signals to set the IC into write mode. So, unfortunately, this method will not work there.
I know, that the TL866 can program GALs and such things, I'm actually using the TL866 to do that quite often. I don't want to spread wrong information. However, as far as I know, even if you can see VPP in the UI, it has no meaning, or means the same as VCC. GALs are not programmed in the same way as EPROMS. There is not just a pin, where you put some higher voltage, but a combination of signals to set the IC into write mode. I honestly was never digging into the depth, how that works, but I believe, I read it somewhere a long time ago.
No, I didn't, but I tried plenty of others. I looked into the datasheet and there stands, that you should not exceed 21.5V, so pay attention to stay below or equal 21V.
@@necro_ware I've tried the D2732 with 20,66V on vpp (pin20) without success. Just an error after click on program... Programing FLASH... Programing ... Failed. If someone has any idea
Hi! I would like to ask you something. I have a 386 motherboard (Seritech SER-386-AD III), that is missing the BIOS chip. I've seen that in eBay, they sell 28-dip EPROM chips (32K, 64K and 128K) from 3 to 7 euros. On the retroweb website, there is a bios to download for this motherboard. If I order one of those EPROM chips, can the TL866II+ pass the 386 BIOS to it? And if yes, will the motherboard boot? (assuming the the motherboard doesn't have any other problem and is only missing the BIOS chip).
Yes, this is the way to go. But pay attention, if you get used EPROMs, you will need an UV-eraser. If you don't want to mess around with that, just get compatible EEPROMs
At 2:22 you explain that write mode only happens at 21V. You workaround this with an external power supply but how do you workaround the software to allow you to erase/write to the chip? I am attempting this now with a ST brand M2716-1F1.
First of all erase will not work, since it is an EPROM, which can be erased only with UV light. The programmer will not allow to write to it until it was erased properly. All the other stuff you have to do as I showed in the video. Deactivate Chip ID check and Pin Detection.
@@necro_ware Sorry to have used the word “erase”, to me it also describes writing which is what I cannot perform with this chip model regardless. To my point, I am wondering if in my case, is this is a software/firmware issue. My brand new XGecu TL866II-Plus has App Software Ver: 11.80 and Firmware Ver: 04.2.128. Have you updated these to the newer versions since this video? What version is currently working for you? I am simply trying to troubleshoot why I am having this trouble. I am trying to fix a Space Invaders arcade.
@@necro_ware It just says Programming Failed - The log file agrees. APP Version : 11.80 Model : TL866II Plus, Device : M2716 @DIP24, Programming FLASH ... Programming ...Failed I have tried this with new M2716-1F1 Eproms, new M2716-1F1Eproms erased, I have tried this as you do with VPP isolated with 21.5 volts and then also with 3.5 volts in parallel as supplemental power. The same problem persists, Programming Failed.
Usually, you don't need to make it multiple times. If you have to experiment with PROMs and rewrite them every now and then, I suggest to use EEPROM instead, since they can be easily erased without an UV eraser. Such EEPROMs will not need 21V anyway. So this procedure I describe is more for one time usage and for me, it's better than just to throw away the chips.
@@necro_ware ok thanks. i ordered this V12.63 Original XGecu T48 [TL866-3G] Programmer Support 34000+ ICS for EPROM/MCU/SPI/Nor/NAND Flash/EMMC/IC Tester/ TL866CS TL866II Plus Replacement. If it doesnt work you owe me $61! 🤣
@@necro_ware Would it, though? It says the max voltage on that pin is 18V. I'm not sure it would burn with 21. Besides, other similar models support 21V.
@@LambertZero If it would, I can't say, I just think, that it could, dependent on the internals of the programmer. I'm not really keen to find it out ;)
Unfortunately, I don't have any PLS100 chips, but I looked at the datasheet of the IC and it doesn't seem to be related here. This PLD is not supported by TL866II+, so you'll probably need some other programmer and if the voltage there is not sufficient, this method could probably work, but you have to try it yourself, I guess.
@@necro_ware thanx, i read in a datasheet from a MBM27128 (old fujitsu eprom) that if you want to read the memory you will need Vcc and Vpp at the same value, for example, 5 volts, its that true?
