Thread
How do you know if its the orginal Macintosh M0001 model?
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
serial number: F4060AHM0001
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.
If it was originally a 128k, it has been upgraded.
the model name at back is just "Macintosh". what do you mean "If it was originally a 128k, it has been upgraded." ?
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.
In short it is/was an original Mac, but it's not in original condition.
thanks. 
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".
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.)
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.)
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.
will post some pictures later or tomorrow.
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.
here are some pictures i took just now:
or you can go to
for more pictures.
Let me know what you think.
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.
Dang. I wish my 128K had come that way.
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?
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?
All I can say is
which one?
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).
WOW! That's great! I'm glad it turned out that you have the original mobo... congrats!
Very nice! And wow at the size of that ram upgrade board.
The RAM chips on the motherboard are two rows of 8 chips. they're at the opposite end of the motherboard from the connectors
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!
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!
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.
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.
What is the possibility that the mobo RAM chips were not upgraded to 512K?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!
Will try to open it up again.
It is possible, but since it was much more common to upgrade the motherboard than to add a daughterboard, the mobo was nearly always upgraded first. The guys at MacMemory started out doing 512K upgrades, and later made a larger version of the Beck-Tech add-on that held 1MB. Note also that MacMemory made an attempt to accommodate 18-pin 1Mb RAM chips, which would have made the add-on hold 4MB. Unfortunately, I believe their guess as to the pinout of future 1Mb chips was wrong, so it never happened, and of course Apple's architecture limited RAM to 4MB max anyway. That didn't stop MacMemory from advertising "Upgrade to 4.5MB RAM!"
I can't remember whether 1.5MB RAM is one of Apple's configs supported in the Plus ROMs. I know they support powers of 2 (128K, 256K, 512K, 1MB, 2MB, 4MB). Anybody have an example of an odd memory config working?
I recall the Plus supported 256KB SIMMs and 1 MB SIMMs, in any combination of pairs. So 2x256 (which would be strange, since it's lower than it shipped with,) 4x256, 2x1MB, 2x256+2x1MB, 4x1MB.
Of course, that's 2.5MB! :I
The SE/30, with its eight banks, could do 1.5 MB, as 4x256 and 4x128, although I don't think 128s were officially supported, and were exceedingly rare. (I think I have two of them, I suppose I could try them on my Plus or SE...)
Agree with H3NRY. Almost all upgrade cards required 512K on the motherboard. However, correct me if I'm wrong H3NRY, a few bypassed the logic board altogether? It would be the exception if yours did this.
Anonymous Freak, are you saying you have 128K SIMMS? So you could have a Plus with only 256K RAM? Now that would be an experiment worth trying, eh Bunsen? I do seem to recall back there somewhere when I was looking to do this, being told that the Mac is not wired to support odd RAM configurations.
Anonymous Freak, are you saying you have 128K SIMMS? So you could have a Plus with only 256K RAM? Now that would be an experiment worth trying, eh Bunsen? I do seem to recall back there somewhere when I was looking to do this, being told that the Mac is not wired to support odd RAM configurations.
I have no idea if the 128K SIMMs work with any Mac. I suppose I could try, though. At worst, it'll beep at me. (I could try it in pair with a couple known-size SIMMs, it would be funny to have a 768KB Plus. 
)
)How do I adjust the voltages? sorry for asking im not that expert but i can do it if you let me know how.
I believe this details the procedure:
http://68kmla.org/files/classicmac2.pdf
http://68kmla.org/files/classicmac2.pdf
Now if only you had 64K SIMMs. Then the Mac Plus could be every Compact Mac from the 128Ke, 512Ke through the Plus. There is some speculation that the 64K ROMs also work in the Plus. I believe it is Tom Lee who once reported he put 64K ROMs in a Plus and powered it on before he realized his mistake. So he did not confirm how well it ran in that condition. I have some spare 64K ROMs from dead boards, I should give it a go. Surely it couldn't damage anything?
It ought to be safe. The 64K ROMs will only recognize 512K of RAM and won't initialize the SCSI port, but it should be safe, ie. no smoke. It was common to have Fat Macs with added RAM and SCSI upgrades, and they were essentially Plusses with 64K ROMs. The only fly in the ointment might be that the ROMs would be writing the screen at the wrong address, so you might not get video.
It looks like you're right 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!
Here's the mobo after removing the MacMemory RAM board:
and here's the MacMemory RAM board:
Now as you can see from the pictures, there are two chips missing/removed from the mobo. My question is, can i still start(power on) this mac without the MacMemory RAM board?
Does anyone knows where can I get those missing chips and original 128k RAM chips? I hope to really restore this mac to its original components.
More than two chips, I count four. And no the board will not power on with those chips missing. It won't hurt anything to try, but it is unlikely.Now as you can see from the pictures, there are two chips missing/removed from the mobo. My question is, can i still start(power on) this mac without the MacMemory RAM board? ... Does anyone knows where can I get those missing chips and original 128k RAM chips? I hope to really restore this mac to its original components.
That's going to be a substantial job to restore the logic board, and it will never be original condition. Your best bet is to start looking for a new one. The really sad part is for those missing chips, they've placed sockets, but not for the new RAM. Very interesting RAM chips by the way - never seen any like them before.
The chips you are missing are easy to replace without any soldering as they will easily socket right in. I am a little concerned about those strange single and double pin sockets at D3, E3 & F3. Do they merely tap into the traces? Or have the traces been severed? The biggest repair you will have is the 7-pin socket at E3. This is where the mini-multiplexer was typically installed to upgrade 128K boards to 512K RAM. It required the board to be physically modified. Look underneath and you will see traces have been physically cut. Possibly at other locations on the board too considering some of the strange sockets. Otherwise, it is typically left empty for a 128K. G4 & F4 are simple resistor arrays like the one at E3. E12 & E13 are identical LS244 chips, which you will see mounted directly above the sockets on the RAM board. I wonder if these were actually removed from the Mac and used on the RAM board?
Note you have the aftermarket resistor array added to D15. This was added to the logicboard in any repair to the 128K to prevent a certain kind of lock-up. It is rare to fins a 128K without this added. And, it was mandatory in a 512K RAM upgrade. This might explain why the board was upgraded and the analogue board still has its upper heat sink fin. On the other hand, it could also be that the logic board is not original and one that had already been prepped for the RAM upgrade and merely swapped for the customers in a quick exchange. Anybody know how common that kind of thing was? The 68000 chip is typical of much later Macs, not one as early as this which would still have the the metal square on top.
There is some good news though. If you intend to merely operate the board as a 128K (not restore it), with the missing chips replaced, severed traces mended, and without any additional circuitry in the D3 location, I understand the additional RAM will not be recognized by the Mac, and the board even with 512K RAM installed, will operate normally as a 128K board. It has always been my intention to find a key connection in a 512K upgrade so install a switch that will simply engage or disengage the circuitry depending on how much RAM I want to use. There's a thread about that somewhere, including one about toggling between 64K & 128K ROMs too. Just never got around to investigating it and didn't want to risk damaging anything without more details.
Anonymous Freak – check this out regarding 128K SIMMs.