Hi Mike, I think it is common. I think a lot of these parts were ordered pre-programmed at the factory, so a lot of New old-stock parts may actually beMessage 1 of 7 , Feb 14, 2012View SourceHi Mike,
I think it is common. I think a lot of these parts were ordered pre-programmed at the factory, so a lot of "New" old-stock parts may actually be programmed, and it would be difficult for a distributor to tell without actually testing.
For what it's worth, I hadn't heard of Unicorn at that time, and by now, I have bought a number of parts from them, and have found their service and their parts to be excellent. I would definitely call them if your part it pre-programmed.
A while back, I repaired an Asteroids Deluxe board, and I bought several 74S287 and 82S129 proms from one mail order company and Fry's, and found them all to be pre-programmed. At first I thought I was doing something wrong. Here's the thread:
I finally got a couple of blank PROMS from a vintage arcade parts seller online.
BTW, here's my repair log for that board:
... Thanks, Mike, I found arcadechips.com last night and he supposedly has them in stock. I left a message, asking about them, as well as one for Unicorn.Message 2 of 7 , Feb 14, 2012View SourceOn Tue, 14 Feb 2012, Mike wrote:
> I've encountered burned bi-polar PROMs sold as "new" only once, and the seller refunded my money, so it wasn't a big problem.Thanks, Mike, I found arcadechips.com last night and he supposedly has
> arcadechips.com has excellent prices for proms, including a good selection of bi-polar varieties.
> Mike Willegal
them in stock. I left a message, asking about them, as well as one for
Mike Loewen mloewen@...
Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
Just to be on the safe side, I ran through the complete voltage and performance checks for the Data I/O 29B and UniPak2B. All voltages and waveforms were wellMessage 3 of 7 , Feb 16, 2012View Source