Apple II plus diagnostics card / ROMs

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Apple II plus diagnostics card / ROMs

Hi again,

So I'm still trying to get my EuroPlus working reliably. It's getting there, but I'm having a hard time tracking down some faults. 

(I've bypassed the PAL card for now, and I have a spare coming in a few weeks that'll help me isolate that part donw)

For most other systems I've worked with, there's usually a diagnostics card / cart / ROMset available. I know the later models had diagnostics built in, but this is only a Plus. 

Is anyone aware of a card / board / ROMset out there to do low level diagnostics on the earlier Apple II systems like mine? (Something I can buy without having to pay inflated Ebay prices would be good)

Cheers and thanks in advance. Man, this is a learning experience :-) I've already nicknamed this system my "Cranky Apple" as it just seems irratable all the time.

 

John "Cheshire Noir" Parker

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OK so THIS LINK seems to have

OK so THIS LINK seems to have helped me test the memory at least. I'm trying without my language card as that seems to be causing some issues. If I can get it to boot reliably off disk I can move forward.

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Hi, Could you please be more

Hi, Could you please be more specific about the errors you are getting?

wm

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wment wrote:

[quote=wment]

Hi, Could you please be more specific about the errors you are getting?

wm

[/quote]

Well I'm confident the Language card has an issue now. With it in Apple DOS 3 won't boot at all. It does the initial grrriiind then stops.

Without the language card it's booting off the System Master 3.3 disk, but crashing with a Syntax Error (followed by a random line number such as "Syntax error in line 90", "Syntax error in line 105")

I also sometimes get what looks like a register dump. eg: DE68-    A=04 X=ED Y=00 P=34 S=E9

(those look suspiciously like 6502 register names)

Sargon II seems to boot OK

Broderbund Labyrinth does not. (It flashes an exclamation and then beeps, then repeats)

Unfortunately without the language card I can't run ATDPro

 

Not sure if it's related but some of the keys are prone to repeating.

 

I've carefully cleaned the drive heads with isopropanol and a soft cotton bud. 

 

Running the memory test from this thread is currently producing an error code of 7FFF-00 (01). I've been trying to swap chips between rows D and E but it's a slow, laborious process.

(Anyone know a good source of NOS RAM compatible with the Apple II plus?)

 

Cheers!

 

John

 

 

 

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The apparently random looking

The apparently random looking boot errors for games, can be insufficient memory.  Without the 16k in there you've probably got 48k available.  This will work for pretty much all older games, but there are plenty looking for 64k some bomb more gracefully than others.   What you could do is pull the ram chips one at a time and feed them into the motherboard in a specific location, and try booting, until you find ones that won't work... you may not need to replace them all... out of interest where in the world are you?

 

 

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Spectre wrote:

[quote=Spectre]

What you could do is pull the ram chips one at a time and feed them into the motherboard in a specific location, and try booting, until you find ones that won't work... you may not need to replace them all...

[/quote]

Was trying to avoid having to do that, if possible, especially as I don't know if there's one bad RAM chip or many bad RAM chips. I wonder if I can steal the chips from the language card? (They're Intel D2117-3). Is there a RAM specification that I should be targetting? Mine appears to hold a whole mess of randomly branded chips.

 

[quote=Spectre]

out of interest where in the world are you?

[/quote]

Perth, Western Australia. The next major city is Adelaide, a short 2600km drive away :-) I'm lucky to have accumulated as many systems as I have here. I usually pay more for shipping than I do for the system. Otherwise I'd have many many more systems :-)

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Ram Chips

Have you just tried to re-seat the ram chips? You dont actually have to remove them completely. Slightly pry up one end enough for the pins to move in the socket and then push them back down. I have seen some of the pins actually black from oxidation.

wm

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Ram Chips

If your motherboard has 3 rows of 8 chips then the chips on the motherboard and on the 16k ram card should be of the same type. Numbers will vary depending on the mfg. They are 16k x 1 or 4116 as a generic identifier.

wm

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wment wrote:

[quote=wment]

They are 16k x 1 or 4116 as a generic identifier.

wm

[/quote]

 

Cheers for that. The intel D2117 chips appear to be compatible with 4116 so I'll start swapping stuff out when I have a chance. (A new toy came in for my C64 so I'll be playing with that for a while instead.)

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Some progress

So I gave in and ordered a buttload of memory, and now my base 48K seems to work fine. Or at least it's passing the memory test. I've swapped out the RAM on the language card but that still seems to be having problems. It's an MPC AP-16 memory card (See this post for someone who also apparently owns one)

 

I'll be working on this card next I guess :-) Anyone got any suggestions on where to start? I'm thinking measuring voltages on the bard might be a good start, and if I can get a logic probe, see if there's any chatter on the card itself.

 

This IS an adventure!

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You should be more specific

Spam deleted - Tom

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No error. Just memory

No error. Just memory corruption issues. Crashes to the disassembler. Programs crashing. All goes away when I remove the language card. I guess I was hoping for links to resources on how to diagnose the language cards.

So far I've checked that the memory is getting the correct 12, 5 and -5 voltages. I'll be getting a logic probe today so then I'll be able to prowl around "sniffing" to see if I can see all the clocks flowing around. At this point I'm guessing what to do next.

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Well I'm getting there.

Well I'm getting there.

I've now tracked down:

  1. A bad DRAM chip on the mainboard. (Managed to fry two more while tracking it down, through my own stupidity). I'm now 100% confident all the RAM on the mainboard and the language card is good.
  2. A bad cable on the language board. (That one surprised me. Had to manufacture a replacement out of some ribbon cable and some tuned pin sockets.)

 

What I now get when the Language board is in is a wall of "?" on the screen.

 

Plugging in my logic analyser (First time I've used it "in anger") I can see clock on the RAS line but CAS is being held high.

 

I also have checked all the resistors on the board (Mostly because they're easy to check, and it eliminates them in case one goes open circuit)

 

Next step (having priced it out) is to simply swap out all the 74 series logic on the language card with new chips. Total cost will be about $14 AUD (Or about $5 USD) and then I'll simply swap the chips one-by-one until I get there. Unfortunately I haven't been able to source any 74LS09 chips locally, so I'll test that one with the logic analyser, gate by gate just to make sure that chip, at least, is OK.

 

I've also traced the vast majority of the PCB for the language card and dumped it in KiCAD, which has been very helpful for tracing where everything goes. A bit more work and we could probably make new Language cards :-D

 

Hopefully me recording this progress will help people coming after to diagnose problems with these setups.

 

Cheers!

 

John

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I'm not familiar with your

I'm not familiar with your language card, but I'm guessing that like many others it has a 16-pin ribbon cable jumper that goes into one of the RAM sockets on the MB.  I have had trouble with these ribbon cables in the past, the symptoms very much like you describe.  It would be handy if you could get your hands on another to test.

 

Never mind, I should have read your last response better ... Doh!

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BillO wrote:I'm not familiar
BillO wrote:

I'm not familiar with your language card, but I'm guessing that like many others it has a 16-pin ribbon cable jumper that goes into one of the RAM sockets on the MB.  I have had trouble with these ribbon cables in the past, the symptoms very much like you describe.  It would be handy if you could get your hands on another to test.

 

Never mind, I should have read your last response better ... Doh!

All good :-)

 

Since then I have "brute force" swapped out ALL the 74 series logic on the language card and all seemed good... for about 15 minutes. Now the main memory is playing up again, so I am going to be playing with the support logic again.

(Symptoms currently are very variable. For a while there were no symptoms, except I couldn't boot ProDOS. It would just spin it's wheels. Now it's crashing to the monitor on boot or displaying random length rows of ?)

 

Oh "joy". Nearly chucked it in the bin there and then I can tell you. 

 

Ah well, this is what hobbies are for, right?

 

John

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Still sounding like a bad

Still sounding like a bad connection of some sort.  Get a magnifier and inspect all the solder connections on the MB (at that slot) and on the language card.  A lot of work, but .... that's what hobbies are for.  The resolution will be the reward and bring a unique sense of accomplishment.

 

Do you have a decent oscilloscope?

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BillO wrote:Still sounding
BillO wrote:

Still sounding like a bad connection of some sort.  Get a magnifier and inspect all the solder connections on the MB (at that slot) and on the language card.  A lot of work, but .... that's what hobbies are for.  The resolution will be the reward and bring a unique sense of accomplishment.

 

Do you have a decent oscilloscope?

Well I've done some more unplug/replug of chips around the memory area (Not the RAM, which has already been swapped, just the 74 series logic on either side) and I've cleaned some really disgusting chips and deoxited the sockets they were in. It's now quite stable without the Language card. (Was playing Labyrinth from Broderbund for a bit there)

 

With the language card it boots fine to normal BASIC, but I can't boot DOS 3.3 (It starts to load then the drive stops spinning) or Labyrinth (The drive never stops spinning)

 

 I do have access to a combined scope / logic probe. (One of these)

 

Cheers!

 

John

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CheshireNoir wrote:BillO
CheshireNoir wrote:
BillO wrote:

Still sounding like a bad connection of some sort.  Get a magnifier and inspect all the solder connections on the MB (at that slot) and on the language card.  A lot of work, but .... that's what hobbies are for.  The resolution will be the reward and bring a unique sense of accomplishment.

 

Do you have a decent oscillosco

Have you resolved the cause of these issues? One of my language cards does the same bloody thing. 

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