Mac Plus error code

[IlikeTech]

I recently got an old Mac Plus, but it throws the error code 038000 after chiming.

Any ideas what this means? I read that it could mean a memory problem.

Thanks,

IlikeTech

 

[BadGoldEagle]

Yeah you're right. That is indeed a memory problem. According to Larry Pina's The Dead Mac Scrolls this code means there's an issue with SIMMS 2 and/or 4.

You should open it up, remove the logic board as well as the 4 simms, clean the pads/sockets and retry. 

But the RAM is probably bad. It happens. You can get new simms on sites like welovemacs or any equivalent.

 

[IlikeTech]

Yea, ok. I am wondering if it is just standard 30 pin simm 150ns or less RAM.  Also, do all slots need to be populated?

 

[bibilit]

IIRC the minimum is 1 Meg, meaning all slots populated with 256 k sticks, Yes you need to have all of them populated, using two 1 Meg in the A bank (the one closer to the Processor) and leaving 256 Ks in the B Bank will give you 2,5 Mo of memory... but a pair of resistors should been removed or clipped (R8 and R9)

Max ram is 4 Meg.

Yes standard 30 pin simm 150ns.

 

[IlikeTech]

I tried reseating the simms, with no luck. I just ordered 4 1MB 70ns simms for about 16 dollars shipped. I will blow out the sim sockets before I install them. I sure hope this works, because I don't want to spend all that much more money on it.

 

[BadGoldEagle]

You'll have to disable one 256k resistor to enable the 4Mb upgrade if it hasn't been done before. 

Check your logic board: for full 4Mb support, clip one end of R8 '256k bit'. Technically, R9 shouldn't be there. If it is, clip one end of that one too.

 

[IlikeTech]

Both were already clipped. Someone had tried to upgrade it in the past, and I think that why it had a memory problems.

 

[IlikeTech]

UPDATE: Replacing memory solved the problem. Mods, please close this topic.

 

[BadGoldEagle]

Great! Now you just need the keyboard and the mouse to go with it.

 

[IlikeTech]

Yeah! I posted a want to buy. Does 40 dollars sound reasonable?

 

[Compgeke]

I got my Plus keyboard off ebay for $30 late last year and the mice are a fair bit more common. Seems reasonable enough, however just note you might need to find a straight through 4P4C cable depending on whether or not the keyboard comes with one. The ones from a telephone headset are crossed and will most likely damage the computer, keyboard or both.