Get an AC adapter or powered usb hub to go with it.
Here is the chart Coyote is talking about.
For old EPROMs, you have to pretty much use a 2nd source or gray market product. China makes clones of the smaller EPROMs that no main manufacturer is still producing. They work fine for the most part.
Another tip.... You can sub larger EPROMs for a smaller one when the pin out matches. Take a 2764 (64Kb) and a 27128 (128Kb). They both are in the same 28 pin package. Yet the 27128 has an extra address line at P26 that is not connected in 2764. That means you can fill up a 27128 with two copies of a 2764 image and use that in its place. So if you don't want to stock 2764, you don't have too. Same goes for 2732 vs 2716 and other larger eproms. A lot of times a 2732 is the same price as 2716, so you dont have to buy both.
Example of new manufactured Chinese clones. I like to use them (pre erased, clean straight legs, typically work fine, cheap).
ebay.com link » 50pcs M2732a 2f1 M2732a Eproms St
Quoted from arolden:
Are these still considered a good choice as a general purpose ROM burner? I am mainly looking to update display, sound and game ROMs on 80s, 90s and 00s games.
Looks like the smallest EPROM listed is 2764. If you plan on doing the 2716, 2532, 2732s for early wms, bally, stern, etc get a GQ-4X and powered USB hub / 9v wall wart so you can do the 25v chips.
Measuring the Vpp the GQ-4X never actually gets to 25v, even with an external power supply and/or powered USB hub, but it still seems to handle most 25v chips. Probably why I had problems getting GQ-4X to do TMS2732. Sometimes they would burn ok and then have bad bits start showing up in 24 hours, burn incredibly slow, or just refuse to burn. I just avoid those EPROMs. GQ-4X handles the china clones of the old 25v EPROMs just fine (assuming the chip is OK) and 2532s.
Quoted from G-P-E:
China doesn't "make" newly manufactured clones. They remove old EPROMs from waste boards, make them look pretty and resell them as new. For now it seems most work but as supplies dwindle....
In most cases you can mix and match revisions and manufacturers. Exceptions to this are the really old EPROMs that require multiple voltages. You can often move up in size easy enough but you need to look at the extended address pin of the larger device. Does it get tied to ground/+5V? Unconnected & floating? Usually they are tied off to ground or +5V.
For example -- a 27C64 doesn't use pin 26. A 27C128 uses pin 26 as the high order address pin. If the destination board has this tied to ground then you simply copy the smaller EPROM into the larger EPROM. If the destination board has this tied to +5V then you double the image or program the smaller EPROM into the larger EPROM's high order of memory.
You can still buy OTP type memories from places like Mouser but smallest is 32K x 8. Search for AT27C256R-70PU.
These are much cheaper than regular EPROMs (just over a buck apiece) but are not eraseable. If you need to update or screw up programming - you simply toss it in the trash and grab another.
You are wrong on this one. They most certainly make EPROMs under the STMicro brand name. Some rogue manufacturer has the functional dyes and makes the parts.
When you order them by the case they even came in fake STMicro branded packaging with some Engrish on it, logo printed wrong, etc.
There are rogue manufacturers pumping out 7400 and 4000 series parts too. Sometimes they have issues, sometims they mark HC chips as LS. But they are new made counterfiets , not refurbs. Fake new made transistors (dodgy as all hell) are out there too.
Quoted from G-P-E:
Those parts are just as bad - they are blatant counterfeits and ST would be real interested in that one. Really importing those by the case?!?! Takes balls bringing those in through customs -> with the right customs agent, a case of those can be accompanied with a $2M fine ($2M for an individual, $5M for a company) plus up to 10 years in jail. I would really think twice about ordering from that source.
ST discontinued 2732s long, long before 2013. They are blatantly taking some parts from 'somewhere' and marking them with the ST logo, part number and selling them as new ST parts. That clearly qualifies them as counterfeit parts.
Those could be 'fell of the back of a truck' parts remarked to make them look like STs. Or maybe trash canned 'failed functional test' parts. Or ... who knows.
When we made parts (yes, unfortunately many were fabbed in China) - functional test was much more stringent than what we pinheads need for our uses. Most "failed" parts would pass what we would consider functional but will fail by small degrees in areas such as access time or power consumption. At the time, more and more of our failed parts were somehow making their way back into the consumer market. To curb this - we had to shred failed parts that were made in China, Korea, Singapore and other far east countries. We still had many parts fall off the backs of trucks. They would ship 100K of one part... and we would receive 95K. Happened quite often and nobody over there gave a fat rat's patootie. "Huh, well... we must have miscounted."
If the Chinese were smart about this - they would sell them under their own name as new parts. Nobody could contest that. New DingDong brand parts would be better than mystery counterfeit ST parts or no parts at all.
I guess box is a better description. 300 or so. First time i ran into those China eprom clones was actually came from an often recommended domestic seller. It was pretty obvious something was up when they are marked M2732A, say PGM at 12.5v, and you need to PGM them at 25v. At 21v they program really slow to the point it is suspicious even tho the data sticks. No problems erasing and re buring a few times at least at 25v.
Most stuff im making now is using bigger sized eproms and luckily legit new ones are pretty easily found. But for old boards that want a 2716/2732, its easy for a hobbyist to snag the aliexpress ebay special. Scraping off old labels, erasing them, bent up legs, then it turns out the chip won't burn... no fun. One time programmables are fine for most purposes. How often are you really going to change the ROMs in a pinball board.
China crap that has wound up in my parts bins on accident that caused issues.
CD4013. Had a stash of these from years ago. Been using them for a while in random boards. Turns out they don't work right in the SB300 sound baard.
CD4070. Chip tester would say it is a CD4070 yet not work in a real circuit (SB300)
CD4051. There was "something" inside this chip as I could get some voltage drop across legs, but chip tester declared them as bad and they did not work. New made looking part.
74LS that are actually 74HCT chips (this one is rampant all over ebay, and shows up at domestic sellers now too). 74HCT240 causes solenoids to pull in while caps are charging and the CPU is /RESET.
IRL540 marked transistor being IRF540 or similar (coil pulse weeny in game play made). China fake transistors seem the be the naughtiest of the bunch. The rogue branded IC chips at least usually work.
FM16W08 new made clones from AliExpress. They where "to good to be true" priced so i wanted to see what was up with them. RAMTRON branded parts visually indistinguishable from legit RAMTRON parts besides a bogus data code. Legit Cypress / RAMTRON FM1608 always came blank, the knock offs had static data on them that didnt look logical at all. The ones i got about only 3/5 chips actually worked, but the ones that did work, seemed fine and electrically the same as a legit FM16W08. They where not pulls and all had the same tooling marks. China seems like that can make whatever components they want as long as the tech is not to extreme. I use legit Cypress parts for NVRAM, they are not cheap.....
China makes brand new crap that can be hard to eye out anymore. Blatant remarks are easy to spot. Here are remarks example.... one of these op amps is not like the others, one of these op amps is not the same!
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