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Mac 128k ~ Plus Analog Board Analysis
- Thread starter JDW
- Start date
Mac128
Well-known member
Following from this discussion http://68kmla.org/forums/viewtopic.php?p=31004#31004 into the correct thread,
JDW, have you seen this board?
http://www.digibarn.com/collections/parts/mac-analog-board/index.html
Would love to know if the backside of the board is 820-0082-"A" which makes sense as the earliest production board i've seen is the "B" rev.
JDW, have you seen this board?
http://www.digibarn.com/collections/parts/mac-analog-board/index.html
Would love to know if the backside of the board is 820-0082-"A" which makes sense as the earliest production board i've seen is the "B" rev.
JDW
Well-known member
Mac128, on my Mac Plus Platinum analog board. removing the white cover reveals the following:
820-0082-Ｅ
©1986
I've updated the description on my associated Flickr photo accordingly.
I also checked the original Mac 128k analog board I removed from one of my 512k machines (which was installed prior to the 512k logic board upgrade, and which shipped with the 128k in 1984). Lifting the gray paper cover (which pre-dates the white vinyl) reveals the following:
820-0082-B
©1983
I've updated the description on my associated Flickr photo accordingly.
When I get a spare moment (I only had "spare seconds" this evening) I will disassemble my two Mac 512's and check their analog board, solder-side data as well.
820-0082-Ｅ
©1986
I've updated the description on my associated Flickr photo accordingly.
I also checked the original Mac 128k analog board I removed from one of my 512k machines (which was installed prior to the 512k logic board upgrade, and which shipped with the 128k in 1984). Lifting the gray paper cover (which pre-dates the white vinyl) reveals the following:
820-0082-B
©1983
I've updated the description on my associated Flickr photo accordingly.
When I get a spare moment (I only had "spare seconds" this evening) I will disassemble my two Mac 512's and check their analog board, solder-side data as well.
Mac128
Well-known member
Great. I thought it would be. And this is your 820-0082-C board:
So that confirms when I have some time, I need to photograph my 820-0082-D board for you to add to your detailed analysis of components.
Once we get a few more detailed entries on the M0001 Registry, a few more differences are going to emerge for documentation. Specifically with respect to eh 630-0102- numbers. As you pointed out in the above flickr entry, this is possibly an "E" rev. As you noted on your 820-E board, there is what appears to me as a "J" hand-written in the white square next to the 630-0102 which corresponds to all of my late model boards. I agree with you on your 820-C board that the 630-E suffix probably delineates some revision which I suspect is to the components used, versus the design configuration. My operating theory is this: based on the 512K logic board which has a single P/N 820-0141-A, but does double duty as 630-0101- (128K) and 630-0118- (512K), I believe the 820 number refers to the same board which has specific traces and architecture common to either the 128K or 512K. The 630 numbers by contrast use the same board but use different component RAM chips and the 512K board adds some extra resistors and an IC, but is otherwise identical component configuration as the 128K board. I call these macro component changes warranting completely different part numbers (0101 v. 0118). By adding a rev. latter to the 630 macro number, one can account for minor changes to the actual components. In the case of the analogue board, a sturdier flyback transformer, etc. for instance. With that in mind, I suspect that since the 630 number remained the same throughout the analogue board design changes, that the rev. letters refer to the consecutive component changes, meaning there are at least 4 production boards: "B, C, D & E" and between those four major changes, the component list remained substantially the same, though sported as many as 10 minor revisions ("A,B,C,D,E,F,G,H,I & J"). So we may be looking for subtle variations in individual components accounting for up to 10 different revisions across the four revised boards. (i.e. the 820-C board design revision may have added a new resistor or removed one, but the type of resistors used from the first 820-B board to the last 820-E board were accounted for cumulatively by the 630 number revisions whether a resistor was or was not present on the previous or future boards – meaning the 820 design number dictated what was on the board and the 630 component number dictated what the component specifications actually were)
Anyway, that's my story until proven otherwise. Then we will have accounted for all of the 120V US domestic boards in excruciating detail and can then start documenting the 220V European boards!
Come on guys! Many of you own 220V Macs! Crack em' open!
So that confirms when I have some time, I need to photograph my 820-0082-D board for you to add to your detailed analysis of components.
Once we get a few more detailed entries on the M0001 Registry, a few more differences are going to emerge for documentation. Specifically with respect to eh 630-0102- numbers. As you pointed out in the above flickr entry, this is possibly an "E" rev. As you noted on your 820-E board, there is what appears to me as a "J" hand-written in the white square next to the 630-0102 which corresponds to all of my late model boards. I agree with you on your 820-C board that the 630-E suffix probably delineates some revision which I suspect is to the components used, versus the design configuration. My operating theory is this: based on the 512K logic board which has a single P/N 820-0141-A, but does double duty as 630-0101- (128K) and 630-0118- (512K), I believe the 820 number refers to the same board which has specific traces and architecture common to either the 128K or 512K. The 630 numbers by contrast use the same board but use different component RAM chips and the 512K board adds some extra resistors and an IC, but is otherwise identical component configuration as the 128K board. I call these macro component changes warranting completely different part numbers (0101 v. 0118). By adding a rev. latter to the 630 macro number, one can account for minor changes to the actual components. In the case of the analogue board, a sturdier flyback transformer, etc. for instance. With that in mind, I suspect that since the 630 number remained the same throughout the analogue board design changes, that the rev. letters refer to the consecutive component changes, meaning there are at least 4 production boards: "B, C, D & E" and between those four major changes, the component list remained substantially the same, though sported as many as 10 minor revisions ("A,B,C,D,E,F,G,H,I & J"). So we may be looking for subtle variations in individual components accounting for up to 10 different revisions across the four revised boards. (i.e. the 820-C board design revision may have added a new resistor or removed one, but the type of resistors used from the first 820-B board to the last 820-E board were accounted for cumulatively by the 630 number revisions whether a resistor was or was not present on the previous or future boards – meaning the 820 design number dictated what was on the board and the 630 component number dictated what the component specifications actually were)
Anyway, that's my story until proven otherwise. Then we will have accounted for all of the 120V US domestic boards in excruciating detail and can then start documenting the 220V European boards!
Come on guys! Many of you own 220V Macs! Crack em' open!
JDW
Well-known member
Mac128, many thanks for reminding me of that particular photo. I've updated the photo description accordingly. I completely forgot that board is now being used in my Mac512 (the 512 without the HyperDrive). That means I only need to crack open my one HyperDrive 512 to check it's analog board data.
I also very much like your theory as to the meaning of the board numbers, and I stand beside you calling on all our friends here at 68kMLA to crack open those Macs and report their numbers!
I also very much like your theory as to the meaning of the board numbers, and I stand beside you calling on all our friends here at 68kMLA to crack open those Macs and report their numbers!
I haven't been following this closely and I'm not up to date on the evidence evaluated, also my memory is leaky, so this may be slightly inaccurate or at least wildly incorrect. But...
My understanding of the 8xx versus 6xx numbering system was that the 8xx number refers to a circuit board design while the 6xx part number is a functional part number. By circuit board design, I mean, just the board art, not any of the components which may be on it.
So, e.g., if you had one circuit board which could be populated differently to make two different functional parts, that circuit board would have a single 8xx number, and a different 6xx number for each way that it might be populated and for each way that it might be sold.
I believe that Apple actually did this with the 7500/8500 motherboard. It's the same circuit number and (I think) it has the same 8xx part number in both machines. But it has different 6xx numbers depending on whether the extra video chips for the 8500 are soldered down.
Also, if you had two different circuit boards which could serve the same purpose, they'd have different 8xx numbers (different board artwork) but might have the same 6xx number if they were meant to be used for the same function in the same machines.
So you can have multiple 8xx boards with the same 6xx number and multiple 6xx numbers being assigned to the same 8xx board. But the distinction (IIRC) is that the 8xx refers to the actual physical instantiation, while the 6xx is a functional part number indicating where that assembly is meant to go.
Or I may be full of horse pucky. But that's what I remember, for what it's worth.
My understanding of the 8xx versus 6xx numbering system was that the 8xx number refers to a circuit board design while the 6xx part number is a functional part number. By circuit board design, I mean, just the board art, not any of the components which may be on it.
So, e.g., if you had one circuit board which could be populated differently to make two different functional parts, that circuit board would have a single 8xx number, and a different 6xx number for each way that it might be populated and for each way that it might be sold.
I believe that Apple actually did this with the 7500/8500 motherboard. It's the same circuit number and (I think) it has the same 8xx part number in both machines. But it has different 6xx numbers depending on whether the extra video chips for the 8500 are soldered down.
Also, if you had two different circuit boards which could serve the same purpose, they'd have different 8xx numbers (different board artwork) but might have the same 6xx number if they were meant to be used for the same function in the same machines.
So you can have multiple 8xx boards with the same 6xx number and multiple 6xx numbers being assigned to the same 8xx board. But the distinction (IIRC) is that the 8xx refers to the actual physical instantiation, while the 6xx is a functional part number indicating where that assembly is meant to go.
Or I may be full of horse pucky. But that's what I remember, for what it's worth.
JDW
Well-known member
trag, your theory makes a lot sense because, as you see in my photo, the 8XX number is etched to the solder side of the circuit board (making that particular 8XX number a true part of the circuit board itself). Thus by logical deduction alone we could guess that the 8XX number refers to the revision of the circuit board traces. But would that 8XX number then extend to the components used on that same circuit board? Again, by logical deduction, I must conclude "perhaps not." Why? Because there is a 6XX on the component side of the board (which is silk screened to the board, not etched into the copper).
So yes, it makes a lot of sense that the 8XX talks about the copper trace patterns on the PCB, whereas the 6XX silked number talks about the components used on that same PCB. And then of course there's the issue of the hand printed letter that follows the 6XX number, which would appear to be a "minor" revision of the components.
Thanks for bring this to our attention!
So yes, it makes a lot of sense that the 8XX talks about the copper trace patterns on the PCB, whereas the 6XX silked number talks about the components used on that same PCB. And then of course there's the issue of the hand printed letter that follows the 6XX number, which would appear to be a "minor" revision of the components.
Thanks for bring this to our attention!
Last edited by a moderator:
chinchilla-99
New member
Hello!
This is my first post here, so I want introduce myself.
My name is Robert, and i'm from Poland, so please forgive me my poor english.
I have small collection about 20 old Macs.
I have Macintosh Plus international 240V version, and I want add some photos of analog board 240V version 630-0108 http://www.flickr.com/photos/34360647@N06/
This is my first post here, so I want introduce myself.
My name is Robert, and i'm from Poland, so please forgive me my poor english.
I have small collection about 20 old Macs.
I have Macintosh Plus international 240V version, and I want add some photos of analog board 240V version 630-0108 http://www.flickr.com/photos/34360647@N06/
Mac128
Well-known member
Welcome, and thank you so much for contributing these photos. You can add them to the 68Kmla Flickr Group here: http://flickr.com/groups/68kmla/
Interesting thread...
The prefix "661-" designated an "exchange module". In other words, these were major assemblies, repaired by obtaining a fresh one from Apple, then sending the faulty one back to be repaired and returned to the exchange pool and eventually sold to someone else as a replacement. You could buy such parts outright and not have to return the faulty one, but the cost was very high - eg 2-4 times the exchange price.
Interestingly, some parts that would obviously not be repaired, still carried 661- part numbers and could not be purchased outright. From memory, these were things like ROMs and case parts. The explanation given at the time was that they were made exchange items to prevent reverse engineering / copyright issues etc. It still didn't make that much sense with cases, since anyone who was seriously attempting to reverse engineer a machine would have just bought a whole machine outright.
In general, the quality of exchange parts was very good (although the later 1.4MB manual inject floppy drives were a hit and miss affair - at least in Australia). Apple considered exchange parts to be "rebuilt as new". Through the exchange process, it was possible for an early model analog board PCB to have been rebuilt to carry the component upgrades required to meet the final Mac Plus analog board specs. In this situation, the screen printed board number would still designate it as an "old" board, but it carried the new, upgraded components. The exchange system grated somewhat with me, when you consider that a customer bringing a near new Plus in for a replacement floppy drive may have received a rebuilt 3 year old floppy drive that had copped a beating in a school or similar.
The late model boards with the white polyester capacitor at the top appeared in the very last run of Mac Plus computers sold in Australia. This may have been due to the launch of the Classic being delayed in Australia by some time due to huge demand in other markets (i.e. the USA) - Apple may have done one last run of Pluses to pacify markets that couldn't get the new Classic.
The very last Plus had some minor changes to the logic board too. These included a separate little metal ground clip that shipped separately to the board in a tiny clear plastic jewel case. Earlier logic boards were exceptionally reliable, but for some reason many of the final run of logic boards had to be replaced under warranty. I built a little "wall" on top of my work bench, made out of the jewel cases mentioned above.
I have an anecdote regarding the origin of the final analog board configuration. I'll put it in a separate post sometime...
Correct. Apple service providers were instructed to always ignore the part numbers screen printed on the board. There was a book used to identify parts - usually from photos, with notes guiding you as to subtle differences between boards (i.e. if the IC at position X carries part number yyy-zzz, then it's board A, otherwise board B and so on) - but it didn't use the screen printed part numbers for identification.
The prefix "661-" designated an "exchange module". In other words, these were major assemblies, repaired by obtaining a fresh one from Apple, then sending the faulty one back to be repaired and returned to the exchange pool and eventually sold to someone else as a replacement. You could buy such parts outright and not have to return the faulty one, but the cost was very high - eg 2-4 times the exchange price.
Interestingly, some parts that would obviously not be repaired, still carried 661- part numbers and could not be purchased outright. From memory, these were things like ROMs and case parts. The explanation given at the time was that they were made exchange items to prevent reverse engineering / copyright issues etc. It still didn't make that much sense with cases, since anyone who was seriously attempting to reverse engineer a machine would have just bought a whole machine outright.
In general, the quality of exchange parts was very good (although the later 1.4MB manual inject floppy drives were a hit and miss affair - at least in Australia). Apple considered exchange parts to be "rebuilt as new". Through the exchange process, it was possible for an early model analog board PCB to have been rebuilt to carry the component upgrades required to meet the final Mac Plus analog board specs. In this situation, the screen printed board number would still designate it as an "old" board, but it carried the new, upgraded components. The exchange system grated somewhat with me, when you consider that a customer bringing a near new Plus in for a replacement floppy drive may have received a rebuilt 3 year old floppy drive that had copped a beating in a school or similar.
The late model boards with the white polyester capacitor at the top appeared in the very last run of Mac Plus computers sold in Australia. This may have been due to the launch of the Classic being delayed in Australia by some time due to huge demand in other markets (i.e. the USA) - Apple may have done one last run of Pluses to pacify markets that couldn't get the new Classic.
The very last Plus had some minor changes to the logic board too. These included a separate little metal ground clip that shipped separately to the board in a tiny clear plastic jewel case. Earlier logic boards were exceptionally reliable, but for some reason many of the final run of logic boards had to be replaced under warranty. I built a little "wall" on top of my work bench, made out of the jewel cases mentioned above.
I have an anecdote regarding the origin of the final analog board configuration. I'll put it in a separate post sometime...
JDW
Well-known member
Interesting "post" indeed, shred!
Here is a photo of C1 in a later edition Mac Plus analog board.
Here is a photo of C1 in a stock Mac 128k analog board.
You wouldn't happen to own a copy of that book, or have copies of the pages in question, would you?
You are talking of C1.
Here is a photo of C1 in a later edition Mac Plus analog board.
Here is a photo of C1 in a stock Mac 128k analog board.
chinchilla-99
New member
No, sorry. It took the form of a large ring binder book. Every month an "update" would arrive with instructions to remove this page, insert that page from the update and so on. As such, it was always up to date, but you only ever got the one copy of it.
I think I have some old parts price lists somewhere. They take the form of HyperCard stacks.
I probably should point out that Apple always referred to the "analog board" in the 128 / 512 / Plus as the "Power / Sweep Board".
JDW
Well-known member
shred, I would love to see those stacks.
chinchilla-99/szynszyl_99, I found your photo interesting. But unless shred has evidence to the contrary, I am going to assume that the "3" in your analog board's part number sticker pertains to international boards only, as opposed to a newer edition of the 630-0102 US boards. The latest edition US board I've seen, based on the handwritten letter following the part number, are marked "E." Here is my photo of an "E" board.
chinchilla-99/szynszyl_99, I found your photo interesting. But unless shred has evidence to the contrary, I am going to assume that the "3" in your analog board's part number sticker pertains to international boards only, as opposed to a newer edition of the 630-0102 US boards. The latest edition US board I've seen, based on the handwritten letter following the part number, are marked "E." Here is my photo of an "E" board.
Hello all,
I found two mac boards at my high school about nine years ago and I had no idea what they were. I found this forum and topic about 2 years ago, took detailed pictures of the boards and was going to post them to find out what type of mac they went to or what revision they might be. As fate had it I times got hard and I lost my net connection etc...
Well I'm back and here is a link to my flicker page http://www.flickr.com/photos/nexarian/.
I think one of the boards revision code is (630-0525-D), the other one im not sure of.
I'm hoping that I'm not too late and that someone can help me identify these boards. I would really appreciate any help anyone can give me
Thanks
Nexarian
I found two mac boards at my high school about nine years ago and I had no idea what they were. I found this forum and topic about 2 years ago, took detailed pictures of the boards and was going to post them to find out what type of mac they went to or what revision they might be. As fate had it I times got hard and I lost my net connection etc...
Well I'm back and here is a link to my flicker page http://www.flickr.com/photos/nexarian/.
I think one of the boards revision code is (630-0525-D), the other one im not sure of.
I'm hoping that I'm not too late and that someone can help me identify these boards. I would really appreciate any help anyone can give me
Thanks
Nexarian
Mac128
Well-known member
Take the vinyl covering off the back and get your 820-number. Your flyback transformer is the very latest SE type so this board was likely repaired as the copyright date is that of an earlier model board, early 512Ke or beige Plus at the latest. Not even sure a 512Ke came with anything less than the 1986 copyright board.
