23 Oct
2005
23 Oct
'05
3:12 p.m.
On 10/24/05, Jos Dreesen <jos.mar at bluewin.ch> wrote:
I have a couple of 4116 DRAM's that I like to test.
My approach will be to put an ic socket in a ZX spectrum and just fire
it up with the DUT in the socket.
Speccie works -> DRAM chip OK
Speccie does not work -> DRAM chip dead.
Is this too simpleminded , or are there better ways to test 4116's ?
I did something similar to test 4K DRAMs, but a little more extensive...
I removed a couple of DRAMs from a PDP-11/03 CPU board and installed
sockets. In addition to the CPU, I stuck a Qbus COMBOARD on the
backplane with a Fluke 9010A in place of its 68000 CPU. By setting
bits in the COMBOARD CSR to allow DMA, I mapped the Qbus memory space
into 68000 memory space and used memory tests on the Fluke to test the
memory installed in the PDP-11/03 CPU.
Not the simplest (or cheapest) rig, but I did have all the parts lying
around. My own DRAM tester only does 4164s and up (+5VDC DIP parts).
If you want to test pass/fail, your rig will work fine. If you
suspect flakey operation, you'll want to run memory test patterns on
the chip. One other possibility would be to find an Apple II and
stick chips under test in the high bank and find/write a memory tester
in 6502 assembler. I only suggest the Apple II because they are cheap
and plentiful (and they use 4116 chips).
-ethan