IIe is unwell: drops to monitor

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IIe is unwell: drops to monitor

I recently picked up a IIe and a IIgs (plus, incidentally, the whole II/IIgs disk library from LOGIC, a local Apple user group that shut down recently). While I've got the IIgs working nicely with ADTPro, the IIe + DuoDisk is not so happy.

  • makes all the right beeps, ‘Apple //e’ display and floppy noises immediately after powering on
  • Ctrl-Break gets into Applesoft BASIC as expected
  • Booting a DOS 3.3 master fails, dropping back to the Monitor with messages like “1BC1-  A=B9 X=0 Y=F1 P=B5 S=FB
  • Trying ProDOS fails similarly, dropping out with “PP«newline»0002-  A=D0 X=0 Y=02 P=37 S=F1
  • ADTPro's serial bootstrapper fails with similar messages, but with some screen corruption
  • If I do manage to get ADTPro loaded, it doesn't recognize any floppy disks being in the drive.
  • The one game disk I managed to load ran with some screen noise.

The same DuoDisk worked okay with the IIgs, and a working UniDisk I have fared similarly badly on the IIe.

I know next next to nothing about Apple IIs: never used one before last week. The screen corruption made me think that it might be chips coming unseated, but everything I could see was in place.

I do have a spare Extended 80-column card and could swap that in, but is there any other obvious issue I should look for? Could it be a disk controller card problem?

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Re: IIe is unwell: drops to monitor

sounds far more like a damaged RAMchip on mainboard...
perform RAMtest program
sincerely
speedyG

1978AppleII's picture
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Re: IIe is unwell: drops to monitor

Here's the memory test from an older post:

First, I suggest you try this simple 48K RAM test (thanks to Jim Sather and his precious book "Understanding the Apple II") :
1. Go to the monitor (CALL -151)
2. Type in the following code (don't forget the space between 34:14 and Return).

C050 C053 C054 C057 N 265:FF N 266<265.BFFEM 266<265.BFFEV 265:0 N 266<265.BFFEM 266<265.BFFEV 34:14 (Return)

The Apple II will go to HGR mode and display white and dark graphic screen along with question marks and inverse @ characters at the bottom of the screen.

If some RAM chips are bad, faulty addresses will be printed on the bottom of the screen.

Make sure there is a space between the 34:14 and the RETURN otherwise it will only run once.

If any numbers/letters/memory locations are printed out you have bad ram.

Jennifer

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Re: IIe is unwell: drops to monitor

Ah, thanks. Lots of errors found.

If I have a note of the failing addresses, can I work out which chips are faulty? The main board has RAM sockets (yay!) and it looks like at least one of the chips has been replaced.

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Re: IIe is unwell: drops to monitor

Each ram chip covers all addresses but only one bit of data. Hold down both open and closed apple keys while powering on. It will run a self-test
including ram. See if it reports an error.

Larry G

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Re: IIe is unwell: drops to monitor

Looks like chip 4 of 8 is dead, as I get RAM 0 0 0 1 0 0 0 0. Time to get some new 4264s.

Thanks for all the help!

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Re: IIe is unwell: drops to monitor

I guess I'm really lucky to have a friend, Josh, who happens to have a huge stash of Micron 4264s and mad skillz in the diagnostics front. Thanks, Josh — I have a working IIe now!

The Micron 4264s appear to be 4164 chips, as TI 4164s seemed to work equally well.

What we found out is that the Apple-Apple RAM test tests 80 Column Card memory first, then main board memory. At least one chip on the 80 column card was bad, and one on the main board. Probably a good idea to take all the boards out first.

Thanks to all for the great suggestions.

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