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I made a 12-27V EPROM programmer 8)
Posted: Mon Mar 18, 2024 9:23 pm
by AndersNielsen
I hate to toot my own horn but I have to admit I'm happy with how this turned out and I can't wait to get it on a PCB. In here I guess making a ROM burner must be a rite of passage.
Mostly I'm proud of the price - got the BOM down to where it should be affordable for anyone to put one together.. Lowering the bar for using a lot of old EEPROMs/EPROMs.
Have a look:
https://youtu.be/mtvinIR8E74
Schematic:
https://github.com/AndersBNielsen/Relat ... rammer.pdf
Re: I made a 12-27V EPROM programmer 8)
Posted: Wed Mar 20, 2024 3:15 pm
by AndrewP
Nice! And whilst I already have a XGecu TL866 II+ I really enjoyed watching the build and how mistakes were found and corrected.
Re: I made a 12-27V EPROM programmer 8)
Posted: Wed Mar 20, 2024 6:29 pm
by AndersNielsen
Nice! And whilst I already have a XGecu TL866 II+ I really enjoyed watching the build and how mistakes were found and corrected.
Thank you! It’s the minority of viewers who enjoy it enough to watch most of it - but that’s the minority I make it for

Re: I made a 12-27V EPROM programmer 8)
Posted: Wed Apr 10, 2024 8:31 am
by AndersNielsen
Re: I made a 12-27V EPROM programmer 8)
Posted: Thu Apr 11, 2024 7:21 pm
by Martin_H
Neat. I built an EEPROM programmer using other projects as a guide, but EPROMs required higher voltage so I couldn't use them.
Re: I made a 12-27V EPROM programmer 8)
Posted: Sat Apr 20, 2024 10:53 am
by Michael
Do you think you might be able to program the 12v 27C' series EPROM's which require switchable 5.0v & 6.25v on VCC and switchable 5.0v & 12.5v on VPP?
I built a programmer long ago for the 12v 27C' EPROM's that connected to my Pete Dunster 68HC11F1 board. It could also program 28C' series EEPROM's.
The 12v 27C' devices are quite popular and readily available (new and surplus). I still have a stash of shiny 'new old stock' 27C' series EPROM's and I considered designing a new Flash programmer with the option of adding a pair of 50¢ MT3608 'boost' modules to provide the switchable VCC and VPP voltages to program 12v 27C' devices since the 'enable' pin on these modules will place either the boost voltage or the 5v input voltage onto the output. It does however require a wee bit of surgery on the modules to expose the 'enable' pin. If you're a frugal shopper, figure about $6 for parts, including PCB and $2 Arduino Nano clone.
For 5v EEPROM, Flash ROM, and nvRAM devices I use an Uno and a programmer shield combo' that costs about $6, including a $3 Uno clone. I purchase Uno clones with a mini or micro usb connector instead of the big honkin' USB connector found on the original Uno.