Does anyone have a way of testing an old memory chip? I have a whole bunch of these out of an old Allen Bradley control cabinet. Some of them are marked P 2107 C-2. They are also described as IC-MOS 4K DRAM Chip. There are 22 pin IC package and I have hundreds of them that need to be tested. I have a BK 575 tester but it won't do the job and BK does not have any updates.
Is there another chip out there in a different package but with the same type of pinouts where I can adapt it to the different chip that possibly the BK 575 can test.
I'd be glad to build a tester for this chip - would solve a real time waster. Now what I do is put a half dozen new chips on the board and see if the exec program for the machine will load. Then I do the Cristmas tree light thing untill I get the bad chips in my hand.
On Sun, 04 Mar 2007 15:33:00 GMT, "Nick" put finger to keyboard and composed:
Does the board have a CPU (eg Z80) with a discrete PROM/EPROM? If so, how hard would it be to program a debug monitor or memory tester into your own ROM?
- Franc Zabkar
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Please remove one 'i' from my address when replying by email.
The board is about 16" square with edge connectors along 1 side and it plugs into a backpane with a bunch of other cards. There is no real CPU or such as these are 1980 CNC controls. There are 34 of these 2107 chips in sockets on each card and they need to be pulled and checked. The easiest way would be a sister card adapted to my BK 575 IC tester. There are no EPROM's on these cards, so something else would have to be done.
One way to check if a DRAM is working is to simply jam a second Known-to-be-good DRAM on top of the suspect one. This often works!
Otherwise there are testers out there on eBay - RAMCHECK, BUGTRAP, and others made test units that would handle these.
John :-#)#
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(Please post followups or tech enquires to the newsgroup) John's
Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com "Old pinballers never die, they
just flip out."
Oh, wait, is the 2107 an 18 pin with triple supply? Then there are not very many test fixtures for it...
John :-#(#
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(Please post followups or tech enquires to the newsgroup) John's
Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com "Old pinballers never die, they
just flip out."
Take the lid off it and you'll see a row of DRAMs just like the ones you want to test, they are socketed. The Right hand one is the most significant bit Set the harmoniser up as a simple digital delay Feed a signal generator at, say, 1khz, in the input and monitor the output on an amp and speaker. Go through your pile of dram chips one at a time, substituting them in the MSB socket, turning off while doing the swaps. Discard the chips that turn the sound to crap. If you want an easy life, plug a 22pin 0.4" zif socket in the MSB socket. Sell the Eventide on Ebay M M
"moby" wrote in news: snipped-for-privacy@c51g2000cwc.googlegroups.com:
Nice. More fun than a dedicated tester (which might cost nearly as much if it's hard to get), and as the Harmoniser is well-liked by many, is guaranteed to resell, and for a profit if you get some nice big photos and a good description. Unless you damage the Harmoniser, it's unlikely that you could lose money this way, and you might like it enough to keep it and use it.
Take the lid off it and you'll see a row of DRAMs just like the ones you want to test, they are socketed. The Right hand one is the most significant bit Set the harmoniser up as a simple digital delay Feed a signal generator at, say, 1khz, in the input and monitor the output on an amp and speaker. Go through your pile of dram chips one at a time, substituting them in the MSB socket, turning off while doing the swaps. Discard the chips that turn the sound to crap. If you want an easy life, plug a 22pin 0.4" zif socket in the MSB socket. Sell the Eventide on Ebay
The old Space Invaders video game used the same DRAMs. Although not part of the Bally/Midway ROM set, there does exist a self-test ROM that you can install to test the RAMs and other game aspects. You should be able to find the test ROM by doing google searches; then all you'd need to do is pick up a working boardset on Ebay; generally less than $150. The RAM test is an audio "beep" code, so you would only need a speaker; the boadset has an audio amp, so no need for external amplification. Wire up a test fixture using pinouts for SI easily found through google searches; you would need an external power supply for -5VDC, +5VDC, and +12VDC (all voltages are needed for the DRAMs).
Best Regards,
John Hermann Buy, Sell, Trade, and Repair Video and Pinball Machines. Located near Dallas, TX.
Look for the Bugtrap 8000 RAM tester. I believe it can be modified to test your RAM. I am looking to make an adapter for mine in fact, along with being able to test 2114s...
John :-#)#
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(Please post followups or tech enquires to the newsgroup) John's
Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com "Old pinballers never die, they
just flip out."
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