as my start into that forum i cam directly with the problem and questions on a defect of an 130XE that i never saw befor. I hope somebody can halp me or give me a little hint were i can search to solve this kind of problem.
okay whats the problem on that special machine. It seams to work fine. it starts, it runs basic, but....the memorytest shows some strange blocks i never seen before on those machines. The short (with Basic loaded) and the long (without Basic loaded) Memorytest show 40/48 blocks of RAM in the first run they all ar white...no red/brown defectiv memoryblocks...but at the and of the first run happens that what i never seen befor in the internal memory test. under the 40/48 RAM blocks were shown 4 bigger brown blocks...see pictures
short memorytest (with Basic loaded):
long memorytest (Basic not loaded):
becaus this problem is special and because some more 130xe mainboards are sleeping in my cellar waiting to be tested i bought the SysCheck Module from tf_hh i started the machine...the MEM Test runs...tells me everything is fine. ROM Checksumm also is fine.
in a conversation with tf_hh he told me to boot the machine and try POKE 54017,252. He told me if the machine get stuck it can't be the MMU or the PIA that causes the problem.
this happens after typing POKE 54017,252 and hit return.
this is the Mainboard of the 130XE with that special problem.
does anyone have an idea what the problem can be?
can anyone tell me what program i need to test the upper 64KB of RAM of an 130XE?
i have two other 130XE that run normal (on both i had to exchange some of the RAM-ICs. but they have an other problem to. at first bootup he boots into Basci normaly but the screen is only black and white and the charakters look a little like a checkerboard. After turning of and on again it mostliy boots up normaly with color screen!
Does anyone know what the reason for that problem can be?
Thanx a lot!!!