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Bought a dirty Apple IIc on eBay...

H

HoJoPo

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So, I decided I needed an Apple IIc for my collection, since the early Apple ][ Plus, enhanced Apple //e, Rom 01 Woz IIgs, Rom 03 IIgs and IIc+ might be lonely.

Trolling around on eBay, I found a VERY dirty IIc "for parts", along with a bunch of floppy disks, a Kraft KC3+ joystick, a PC 720 half height 3.5" drive, and a Unidisk 3.5.

I managed to get it, bidding exactly the same as the other bidders top bid. $50+$45 shipping later, I received the Apple IIc today.

It was VERY dirty, sticky greasy dirt on all top surfaces of the IIc, Unidisk and Joystick. The disks turned out to be a HUGE collection of late 80's / early 90's Computer Science / Math software for the PC, including assemblers, Pascal, C and Modula-2 compilers, and a bunch more, all on high density 5.25 floppies. Unfortunately, not much use in the IIc.

Apple IIc 00.5.JPG

I powered up the IIc and Unidisk, and it immediately made popping noises from the 3.5 drive, trying to eject a disk. There was a DD PC formatted programming scratch disk in it, good thing, the disk protected the heads. It was only stuck in there by the label, so I fished it out and stuck in a 3.5 Apple II Diagnostics v4.1 disk.

The IIc passed the first few tests, then locked up. It would barely pass the tests, the fail the next pass, over and over. So, I decided to take it apart and see what was wrong. I found something amazing in it once I removed the floppy and keyboard:

Apple IIc 01.jpgApple IIc 02.jpg

That's right, it has a Z-Ram Ultra 3 in it! One of the ultimate IIc accessories. But, oddly, it has no RAM on it, all the sockets are empty.

I take it out, finding that it uses stacked sockets to raise the CPU / MMU sockets to the necessary height. So I remove the MMU and CPU from the Z-Ram, and put them in the stacked sockets. It immediately locks up, won't even boot, just a screen full of gibberish.

So, I remove the sockets, and install the CPU/MMU directly on the motherboard. It passes all the tests, over 25 passes without issues! One of the riser sockets is a cheap generic, and I just happen to have an extra 40 pin DIP machine pin socket from my TWGS troubleshooting... so I install the sockets, re-install the Z-Ram (with MMU/CPU relocated to it), and try it out.

Immediately, it crashes in testing again. :( Ok, so the sockets weren't the only problem... I wonder. AE always shipped the Z-Ram Ultra 3 with a minimum of 256k memory. Maybe the MMU isn't happy without at least one bank of RAM.

So, I open up the II plus, and pull out the RamFactor 1MB card. I yank a bank of RAM off of it, and put it in bank "A" of the Z-Ram. Note: the Ultra 3 has the ram chips opposite the other two versions, pay close attention to the chip sockets! Good thing I check the documentation first (Thanks Dr. Ken, your document archive came in handy.)

Boot it up, and, joy, it passes! :D So, I figure, why not put all 1 MB in it while I have it apart, it's a lot easier to put it in now. Of course, one pin, on the very last of 32 RAM chips, bends instead of going in. :( But, with some careful needlenose work, I got it straightened out and inserted.

Ran it for 100 passes on the AE Ram test utility, no issues! It's running the Apple diagnostics now, testing the CPU/RAM/MMU and serial port (internal test)... I'll let it run for a bit, so hopefully it can charge the 3.6v battery for the clock.

Oh, and the clock utility recognizes and sets the clock fine as well. Thanks to the extra disks that Dr. Buggie sent with some IIe stuff I bought, I already had the necessary software for it. :)

I also spent about an hour cleaning it and all the keys with rubbing alcohol, it looks a lot better now:

Apple IIc 03.jpg

Now to find CP/AM 5.1 to test the Z-80 capabilities...
 
Really cool pickup and fun to read through the whole process you went through to get it working! I'd love to have some extra ram in my IIC, but the Z-RAM Ultra is fairly rare.
 
Thanks. I figured the troubleshooting process might help someone else down the road, and should at least be entertaining in the meantime.

I've ordered 50 41256-120ns chips from Jameco, along with a battery holder and 3 AA NiCd batteries, I doubt the GE DataSentry on the Z-RAM is any good (20 year lifespan, it was made in 1986...)

The 50 chips are to repopulate the 1MB I stole from the RamFactor and 512k from a IIgs RAM card I took to fully populate the Ramworks III in my //e. I picked up a couple extras just in case, since I always seem to bend at least one pin during insertion (I do use a chip inserter, but it's a cheap plastic one.) At $.69 each, they were not too bad. Drops to .59 for 100, but 52 spare chips would be a bit much. :)

I also picked up the PLCC puller I keep forgetting, that I need for my Zip GSX upgrade and working on the TWGS.
 
Ok, both CP/AM 5.1 and Microsoft CPM for the Softcard will boot and work on the Z-RAM Ultra III. Odd using Microsoft BASIC on an Apple... though the clear screen command is still "HOME", but you use "FILES" and "SYSTEM", just like the other MS BASICs...

The CP/AM didn't seem to recognize the RAM for a RAM drive like it was supposed to, but it could be I'm doing something wrong. More to play with, I now have CP/M on both my //e (AppliCard) and //c (Z-RAM). Since it has dedicated RAM and a 6 MHz processor, I imagine the AppliCard will be much faster.

Amongst the other items I received lurked a Mouse Systems A+ optical mouse. Unfortunately, I didn't see the special mouse pad for it, until I looked under the PC compatible half height 3.5" drive that came with it... sure enough, there's the mouse pad. Hooked it up to the //c, but only the horizontal sense LEDs lit up, the vertical ones don't. So it only works in one dimension, not the most useful mouse. I may be able to fix it, just need to test the LEDs and their resistors, see if something has gone bad.
 
dorkbert said:
Load up AE's RAMworks test program and run the RAM test.
Click to expand...

The ram test on the AE Super Appleworks Expander 5.3.1 disk passed just fine. Turns out you have to use the MEGDRIVE program to create the RAM disk in CP-A/M 5.1, it works fine.

I managed to get a bootable 3.5" CPM disk made. It uses the hardware 80 col acceleration and auto-loads the MEGDRIVE driver. Reading the CP-A/M 5.1 manual made a big difference, I printed out a copy for future reference (using the booklet print feature of Acrobat and my duplexing IBM NP 17 laser printer).

Been a long time since I used CP/M and CCP/M on my DEC Rainbow 100+.
 
Apple //c went under several revisions:
you can discover which machine you are using issuing the command PRINT PEEK(64447).

If 255 is displayed, you have the first, original model. This model is known to have problems
producing accurate baud rates for serial communications.
If 0 is displayed, you can use 3.5" drives, but you don't have the memory expansion connector.
If 3 is displayed, you have the memory expansion connector and you can plug in extra memory.
If 4 is displayed, you have the latest model with memory expansion connector and extra upgrades.
( If 5 is displayed, you have an Apple IIc+ )

--------

Apple IIc Existing Versions
 
applefreak said:
Apple //c went under several revisions:
you can discover which machine you are using issuing the command PRINT PEEK(64447).

If 255 is displayed, you have the first, original model. This model is known to have problems
producing accurate baud rates for serial communications.
If 0 is displayed, you can use 3.5" drives, but you don't have the memory expansion connector.
If 3 is displayed, you have the memory expansion connector and you can plug in extra memory.
If 4 is displayed, you have the latest model with memory expansion connector and extra upgrades.
( If 5 is displayed, you have an Apple IIc+ )

--------

Apple IIc Existing Versions
Click to expand...

It's a 0, which makes sense, the Unidisk 3.5 works, and there is no memory expansion connector.

Now I need to pre-order one of the Smart Port Virtual Hard Drives... that should make this //c complete. I did find it mentioned that the Zip Chip / Rocket Chip don't fit well between the Z-RAM and the keyboard, so a CPU speed bump isn't likely.

I am looking for an Apple //c memory expansion card for my IIc+, but they seem to be pretty rare. Only one on eBay right now comes complete with a //c, and it's up to $84 wit htwo days remaining.
 
What a find. Nice! Thanks for sharing the troubleshooting process; definitely informative.

Also, re: the idea of buying an early IIc because your other 5 vintage Apples might be lonely -- I like the cut of your jib!
 
Carrington said:
What a find. Nice! Thanks for sharing the troubleshooting process; definitely informative.

Also, re: the idea of buying an early IIc because your other 5 vintage Apples might be lonely -- I like the cut of your jib!
Click to expand...

I'd have mentioned the SE/30 as well, but I'm not sure it likes the others... ;)

Actually, the SE/30 should be happy, I just upgraded its RAM (it had 20 (16+4), now it has 80 (16+64)) in preparation to load up A/UX on it. I've been a Linux user since 1992, and running Unix on a vintage Mac seems about right... if A/UX doesn't behave, I'll throw NetBSD at it.
 
Is anyone aware of an online guide for taking apart a Unidisk? Mine has a jammed plastic head protector (the one that came with the drive way back then). I'm hesitant to go ahead without some guidance. Many Thanks.
 
The Unidisk uses the same auto-eject 800k mechanism as the Mac and the other Apple external 3.5 drives. So the repair instructions for the drive mechanism should be the same.

As for disassembly, it was pretty straightforward. I repaired one using the 800k mechanism from a regular Apple 3.5 drive that had been upgraded to a superdrive using a FDHD mechanism.

Have you tried the manual eject? Take a heavy duty paperclip and straighten it out, then you can insert it into the little hole to the right of the disk slot. Push straight in, and it should eject if the mechanism isn't completely jammed.
 
WOW! That certainly was a great buy for you.

Thanks for sharing the troubleshooting story. It helps to see that a methodical thoughtful approach will pay off. It is still amazing to me how robust this vintage computer equipment is after all these years.

smp
 
That was perfect!!

I managed to remove the drive out of the RFI shield and after a few pushes of the eject mechanism realized that the reason for the jam is that the old lubricant, on the part that is supposed to push out the disk, had dried. I wiped the area with some WD-40 and the eject is now working again.

What is the best way to clean up the old lubricant and what should I apply in its place?
 
Hilal said:
That was perfect!!

I managed to remove the drive out of the RFI shield and after a few pushes of the eject mechanism realized that the reason for the jam is that the old lubricant, on the part that is supposed to push out the disk, had dried. I wiped the area with some WD-40 and the eject is now working again.

What is the best way to clean up the old lubricant and what should I apply in its place?
Click to expand...

WD-40 actually does a decent job removing the old dried up lubricant (spray it on a q-tip around areas you don't want to spray on, like near heads). WD-40 itself it not a proper lubricant, I would suggest some silicon grease on the moving parts, that stuff usually has a pretty good life span, but don't be surprised if you have to re-lube it again in 20 years, no grease will last forever ;-)
 
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