How do you know if its the orginal Macintosh M0001 model?

[giolicious]

i recently bought a 1984 Macintosh model M0001 from ebay. I'm not sure though if this is the original M0001 model. i turned it on with the system disk and clicked on "About the Finder..". I see "512k" with "Version 4.1". What does it mean? it's supposed to be 128k, right? im not sure though.

serial number: F4060AHM0001

 

[aftermac]

What is the model name on the back of the case? Macintosh, Macintosh 128k, Macintosh 512k?

If it was originally a 128k, it has been upgraded.

 

[giolicious]

the model name at back is just "Macintosh". what do you mean "If it was originally a 128k, it has been upgraded." ?

 

[aftermac]

Since it only says "Macintosh" on the back, it is one of the original 128k Mac's. Because you said it is reporting 512k of RAM, someone has upgraded it from 128k to 512k, or replaced the motherboard entirely (most likely).

In short it is/was an original Mac, but it's not in original condition.

 

[giolicious]

thanks.

Since it only says "Macintosh" on the back, it is one of the original 128k Mac's. Because you said it is reporting 512k of RAM, someone has upgraded it from 128k to 512k, or replaced the motherboard entirely (most likely).
In short it is/was an original Mac, but it's not in original condition.

 

[Scott Baret]

The original Macs were called just "Macintosh" since there were no other models to confuse it with. The 128K name came along after the 512K came out, and the badges were changed to differentiate between the "Fat Mac" and the "Skinny Mac".

 

[Anonymous Freak]

Here you go, take a look at the Wikipedia page. Toward the top is a photo of the rear of an "original" Macintosh 128K, showing just the word "Macintosh" on the case badge. In the middle is a closeup of the later version, showing the case badge with 128K added in red.

There is the possibility that someone added one of the after-market 'clip-on' RAM upgrades, but Apple offered good deals on motherboard-swaps, so it probably has the board of a 512K. (Mine is this way; it has a board that was manufactured to be either a 128K or a 512K board, mine is configured as a 512K model. This is even though mine is old enough that it would have come with a 128K-only board originally.)

 

[giolicious]

i will try to open mine later to actually see its logic board just need to go out and buy a torx screw driver.

will post some pictures later or tomorrow.

 

[giolicious]

i opened up my old mac, compared it with the original logic board at http://en.wikipedia.org/wiki/File:Macintosh-motherboard.jpg and i think they are the same board except for the memory expansion on mine.

here are some pictures i took just now:

or you can go to


for more pictures.
Let me know what you think.

 

[Anonymous Freak]

Well, that's an original Macintosh motherboard, alright! (The 1983 copyright on the board shows that.) With a third-party RAM upgrade to boot.

Dang. I wish my 128K had come that way.

 

[waynestewart]

That is a really nice upgrade but the RAM upgrade has 4 banks of 256k so it should show up as 1mb.

I'm wondering why you're seeing only 512k?

Might there be a problem with the upgrade.

Maybe there's a problem with the connection between the upgrade and the motherboard?

Maybe there's 512k on the motherboard and the upgrade isn't showing up at all?

Can you read the numbers on the motherboard RAM chips?

 

[Quadraman]

All I can say is

 

[giolicious]

That is a really nice upgrade but the RAM upgrade has 4 banks of 256k so it should show up as 1mb. I'm wondering why you're seeing only 512k?

Might there be a problem with the upgrade.

Maybe there's a problem with the connection between the upgrade and the motherboard?

Maybe there's 512k on the motherboard and the upgrade isn't showing up at all?

Can you read the numbers on the motherboard RAM chips?

which one?

Well, that's an original Macintosh motherboard, alright! (The 1983 copyright on the board shows that.) With a third-party RAM upgrade to boot.
Dang. I wish my 128K had come that way.

thanks. its a good deal after all even though i waited for almost a month for the package to arrive. its a terrible Customs service here in my country (PH).

 

[aftermac]

WOW! That's great! I'm glad it turned out that you have the original mobo... congrats!

 

[protocol7]

Very nice! And wow at the size of that ram upgrade board.

 

[waynestewart]

The RAM chips on the motherboard are two rows of 8 chips. they're at the opposite end of the motherboard from the connectors

 

[H3NRY]

Your Mac shows 512K because it has the original 64K ROMs most likely. You actually have 1.5MB of RAM installed, it looks like. The mobo RAM chips have probably been replaced upgrading it to 512K and there's 1 MB on the MacMemory upgrade board. If you can find the original software that came with the upgrade, it will let you set up a 1 MB RAMdisk and copy the system & Finder to it. Speeds things up nicely. The other option is to obtain a pair of ROMs from a Mac Plus or 512Ke and install them. They will let you directly address the whole amount of installed RAM. To check whether the mobo is upgraded, check the 16 identical chips under the front edge of the upgrade. If they are labeled something...4164...something, you have 128K. If they are ...41256... you have 512K on the mobo itself.

Apple's original 64K ROMs didn't support more than 512K of memory. The Plus ROMs support up to 4MB of RAM.

In any case, you have a pretty rare early Mac with an early upgrade. Congrats!

 

[Mac128]

Stop using that word "RARE"! :beige:

My recommendation is not to use that RAM upgrade board. It looks like the PSU is the intact original first generation as well. It still has the heat sink attached across the top of the analogue board which was designed to increase heat dissipation, however, it had exactly the opposite effect and traps heat inside the unit.

What is rare is that it is still functioning in this condition. It was standard practice to remove that metal strip during the first repair (which thanks to the strip was guaranteed). The first analogue revision promptly removed it.

The RAM upgrade draws a lot of power and all those 256 chips produce an awful lot of heat (far more than 4MB SIMMS in a Plus). And I would expect H3NRY is correct, most of these RAM upgrades required a 512K RAM upgrade to begin with. Which means your stock board has likely been modified. And as he suggests it would have most likely required software to tell the Mac about the extra RAM with the 64K ROMs. But unlike H3NRY, I would not suggest you go looking for 128K ROMs, to fire it up with. Enjoy the stock analogue board (and most likely components) which is pretty rare, and maintain it as a classic example of an upgraded 128K-512K. But definitely use it sparingly, as that fin really needs to be removed and if the components really haven't been replaced, they are just waiting for any excuse to fail. And start looking for an original 128K board to one day replace it with.

After you remove the RAM board, make sure you adjust the voltages which will fluctuate after removing the draw of the expansion board.

While I have never seen this particular RAM upgrade board (and may indeed be a somewhat "rare" one), there is nothing special about them. They were a very popular enhancement back in the day and the cause of many an analogue board failure. Collectors really don't value them, and as you may have noticed, a 128K in pristine stock condition is far more valuable (and enviable). So remove the board, put it in a drawer and get it out to play with on a cheap 512Ke when you eventually buy one. Do your best to keep the 128K strain free and operating with as many original components as possible (which yours looks miraculously blessed with). Check the voltages regularly and at the first sign of odd behavior, start looking to correct the problems. If the caps are mostly original, just start replacing the major culprits until the problems go away.

 

[giolicious]

Your Mac shows 512K because it has the original 64K ROMs most likely. You actually have 1.5MB of RAM installed, it looks like. The mobo RAM chips have probably been replaced upgrading it to 512K and there's 1 MB on the MacMemory upgrade board. If you can find the original software that came with the upgrade, it will let you set up a 1 MB RAMdisk and copy the system & Finder to it. Speeds things up nicely. The other option is to obtain a pair of ROMs from a Mac Plus or 512Ke and install them. They will let you directly address the whole amount of installed RAM. To check whether the mobo is upgraded, check the 16 identical chips under the front edge of the upgrade. If they are labeled something...4164...something, you have 128K. If they are ...41256... you have 512K on the mobo itself.
Apple's original 64K ROMs didn't support more than 512K of memory. The Plus ROMs support up to 4MB of RAM.

In any case, you have a pretty rare early Mac with an early upgrade. Congrats!

What is the possibility that the mobo RAM chips were not upgraded to 512K?

Will try to open it up again.