checking mem expansion cart

aneurysm · Post by **aneurysm** » Fri Jan 19, 2007 1:25 pm

i used to be able to load VIC Tracker
but now it crashes during the intro
or if i hit space before the spot where it crashes it does a soft-reset
so i was wondering if there was a way to make sure my 16k expansion cart is fully functional and not broken
i've tried it on two seperate vics

ral-clan · Post by **ral-clan** » Fri Jan 19, 2007 2:12 pm

How much RAM shows up when you turn on the VIC?

There is a MEM tester somewhere....I think on funet or Zimmers.

You probably should open it up an reseat all the memory chips, just in case.

6502dude · Post by **6502dude** » Fri Jan 19, 2007 3:35 pm

ral-clan wrote:You probably should open it up an reseat all the memory chips, just in case.

Good idea, but most ram in memory carts is not socketed

Why not try writing small basic program to poke all memory locations of 16K address space with 255, peek adddress, & compare results.

If this process is repeated with value 00 and all compare okay, your RAM expansion should be ok.

eslapion · Post by **eslapion** » Fri Jan 19, 2007 10:25 pm

6502dude wrote:
ral-clan wrote:You probably should open it up an reseat all the memory chips, just in case.
Good idea, but most ram in memory carts is not socketed

Why not try writing small basic program to poke all memory locations of 16K address space with 255, peek adddress, & compare results.

If this process is repeated with value 00 and all compare okay, your RAM expansion should be ok.

Recently, I had a VIC-1111 16k RAM cartridge with a very weird behavior... it gave me random amounts of added memory between 11775 and 19967.

Looked inside, all chips soldered directly to the PCB and nothing seemed wrong.

I just heated all solders points individually to liquify them with my soldering iron set for about 320C (which is rather cool by soldering standards) for about one second each.

Sure enough, after this patience consuming exercice was over, the cartridge worked just as new...

Over time, solder can oxidize and crack...

6502dude · Post by **6502dude** » Sat Jan 20, 2007 12:00 pm

Another thing to check is clean contacts on edge card connector of ram expansion cart.

Some folks suggest cleaning this with pencil eraser.

I prefer to using very fine steel wool. However one must ensure no stray stands of steel wool are present after cleaning.

aneurysm · Post by **aneurysm** » Wed Jan 24, 2007 2:18 am

ok, i finally wrote a little Basic program to poke and peel all the memory of the expansion and everything looks alright
so the problem must be elsewhere...

thanks for your time