Apple IIc doesn't format/duplicate

[Philsan]

My recently acquired Apple IIc read disks perfectly but when I try to format or duplicate disks (with ProDos v1.1.1 or 1.0.2), after the normal drive noise (like start-up one), I get this error message:

4356- A=0C X=60 Y=0C P=30 S=DA

and the red drive light remains lit.

I tried different double side double density disks (the same I use for Commodore 64 and Atari 800XL).

 

[magnusfalkirk]

You are probably using the wrong disks. The Apple II prefers Single sided/Double Density or Single Sided/Single Density disks.

Dean

 

[david__schmidt]

Have you verified if you can write a file on one of the known-good disks? I.e. can your disk write at all? On ProDOS, try:

NEW
10 PRINT "HELLO, WORLD"
SAVE HELLO
NEW
LOAD HELLO
LIST

Does it save without error?

Does your program re-appear?

 

[Philsan]

Thank you guys.

I think my Apple IIc has memory problems.

If I use ProDOS User's Disk (for 64K Apple IIe) instead of Apple System Utilities (for 128K Apple IIe and IIc) I am able to format and copy disks (DSDD).

I've done David's Basic save and load test too.

Moreover, do you think those moving pixels (top right and bottom center) on screen are normal? They are always in those positions.

Loading ProDOS 1.0.2 (instead of 1.1.1) I get the error message you see.

 

[Philsan]

Thanks to ADTPro http://adtpro.sourceforge.net/ I was able to use two test programs.

Master Diagnostics IIc gives "010C – A=BF X=60 Y=00 P=35 S=5E" when I test auxiliary 64K of RAM.

Apple IIc Diagnostics gives "main logic board RAM test failed".

 

[mcdermd]

I know that in the past I've been able to test RAM chips by placing a known good one over each soldered-on chip, leg to leg. When it tests with no error, you'll know which one to desolder and replace. Is there a better way to test them?

 

[Philsan]

mcdermd,

I've tried your method of placing a RAM chip over a soldered-on chip on my Apple IIc.

I have many chips but I am unsure if they are compatible and if they are OK.

What should happen when I place a good chip over a soldered one?

Testing the same soldered chip with my different chips, sometimes I get garbage on screen and sometimes nothing happens.

 

[mcdermd]

Hm. I've used this method with a few old Atari computers. I used a known good replacement DRAM chip and carefully placed it over the old chip, making sure all of the legs contacted properly. If there is only one bad RAM chip on the board, you can find it by hopping the good chip over all of the others one by one until it passes testing. Alternately, you can get a full replacement set and remove them one by one until you find the problem chip(s).

If you've got the time, iron and a sucker, I'd just order a whole new set of chips and do them all at once.

Apple II Csa2 FAQ[/url]"]018- What chip can I use to replace a bad RAM IC on my IIemotherboard?

The 4164 (64k x 1) works on motherboards using eight memory chips. The RAM on my motherboard is in sockets; so, it was easy to replaced a bad memory chip with one.

Jameco sells these for a buck a piece.

 

[Philsan]

Thanks but what should happen when I place a good chip over a soldered one?

Testing the same soldered chip with my different chips, sometimes I get garbage on screen and sometimes nothing changes.

I think nothing should change when a good chip is placed over a good soldered chip.

Are you sure that this method works on Apple IIc?

 

[mcdermd]

I've never tried it on an Apple II but I don't see why it would not work.

On the Ataris I've done this with, placing a good chip over a bad chip will "repair" the bad chip and allow it to boot. If you have any doubts, just desolder and replace them all and you'll be positive the RAM is good.

 

[Philsan]

Are you sure that Jaleco's chips are OK for my Apple IIc?

BTW, I love Atari 8 bit computers...

The chip I used for testings are from Atari 800XL computers.

 

[mcdermd]

According to the Apple II FAQ There they should be. The real way to know is to read the number from the top of the DRAM that's in there now.