Mac 512K/512Ke. Same model, or different?

[Gorgonops]

Interestingly, Apple's model indentifier for the Mac 512Ke is 3, and the Mac Plus is 4. Clearly, despite the 4 month delay in getting the 512Ke out, Apple considered it to be chronoloically first.

A while back there was a long discussion about a simple homebrew SCSI adapter for the original Macs that was published in Dr. Dobb's Journal starting in September 1985. If you compare the design of that adapter (in terms of both hardware and memory mapping) it's actually eerily similar to the Mac Plus' SCSI port. It's not *compatible*, but it's very close, close enough that one just has to wonder...

There's no way of knowing without finding someone who actually worked in Apple's secret laboratory at the time, but it's a reasonable conjecture to suppose that early versions of the 128K ROM might have been developed and tested on otherwise normal "Fat Macs" equipped with a piggyback-board version of the Plus' SCSI port, prior to the Plus' board design being finalized. (Said board was never released as a product by Apple because the "no slot" philosophy meant any such board was the sort of a hack only a third-party supplier could sell with a straight face.) Those same Macs might also of had prototype 800k drives, as Apple started shipping a double-sided version for the Apple IIe/IIc in September 85'. Which means... yes, the 512ke as a prototyping platform almost certainly existed before the full-blown Plus.

 

[Mac128]

The Apple IIe went though at least 3 revisions in it's life, including a major change with the "Platinum" release. It not only had a new case and keyboard, but more importantly had double the RAM and double hi-res graphics! Despite this, most people refer to it as just an Apple IIe. It doesn't even have it's on Wikipedia article! The 512Ke got no such major additions, yet has it's own Wiki article. :lol:

I actually got into a fight on Wikipedia with one of the old Apple II guys there who insisted that all the Apple IIes were nothing more than minor revisions, so much so, that he fought to keep them from even being split into separate sub-headings. Same for the Apple IIcs, which had a similar upgrade history. Totally agree with you. But since I am not an Apple II guy, I slunk away ... life's too short ...

As for the 128Ke, again, I look at Apple's offerings based on marketing (which is why the Apple II fight on Wiki was so frustrating). Not only was the 128Ke not sold as a package, but it was actually discouraged by Apple, so in my mind it doesn't qualify.

Since the 512Ke was a distinct product over the original stock 512K, I have to side with Apple that it was a separate distinguishable model. However, Apple also sold the 512Ke in Europe as the 512K/800. So does that qualify as a separate and unique model, or in the same way the Performas are considered separate models? You certainly wouldn't make a distinction between a Performa 200 and a Classic II. Then again, they are the exact same hardware. The 512Ke is not. Those ROMs make a huge difference in functionality, forget the 800K drive, you can run a 512Ke, or even a Plus off a 400K drive. Essentially the 500K RAM and 128K ROMs allow that Mac to do quite a bit more than a stock 512K or even a 128Ke. Despite being a mere upgrade, it allows the Mac to do far more than the stock model, so claiming a 512K can do some of the things you have it doing, is similar to saying a 512K can run System 6 or can boot off an HD20. Those statements only make sense if you add the disclaimer "with 128K ROMs", or "upgraded". Since 512Ke is the shorthand for those disclaimers, it seems so much easier to say that. Ultimately it makes clear how you are able to do some of the things you do on the 512K, and avoids understandable confusion. I don't have a problem with you calling it a 512K, since I know you know what you are doing, and I know what it takes to do what you're doing, I can infer that what you really mean is an enhanced 512K. For others it's confusing.

 

[JDW]

As if this thread weren't long enough already, I'd just like to add that I somewhat agree with the sentiments of Gorgonops that the 512ke is more like a stripped down Plus than a souped up 512k, due to the ROMs. Honestly, if you have the choice to buy a 512ke or a Plus on EBAY, why on earth would you choose the 512ke? (And the 128ke has such a small amount of RAM it is never a serious consideration for a purchase in my book.) I actually chose my Mac512 over the Plus and the 512ke because it has the original 64k ROMs, yet it has 4 times the RAM of the 128k, making it more usable. And some of the earliest software written for the 128k and 512k (both with 64k ROMs) won't play right with the new 128k ROMs of the 512ke and Plus (as per my memory from the 1980's, which is why I cannot be specific today about which apps won't work on the 128k ROMs).

All said, the 512ke doesn't have much "value" to me (although I would give it more value relative to a 128ke). Ditto for the "ED" model.

 

[Gorgonops]

And some of the earliest software written for the 128k and 512k (both with 64k ROMs) won't play right with the new 128k ROMs of the 512ke and Plus (as per my memory from the 1980's, which is why I cannot be specific today about which apps won't work on the 128k ROMs).

I've seen other discussions about that, and it seems like most of the examples people remember of software "not playing right" were actually traceable to incompatibilities between the 400k and 800k disk drives, not the ROM.

(The 400k drive uses the PWM signal from the Mac to directly regulate its speed, while the 800k drive just turns on the correct speed for whatever track it's on automatically. As I understand it some early copy protection schemes relied on running the drive at a nonstandard speed to read specially encoded data, which of course the 800k drive can't be ordered to do.)

Other incompatibilities were traceable to system versions which supported HFS and hard disks, but the Plus will boot earlier systems, (Obviously at the cost of losing the use of those features.) demonstrating it has *very good* backwards compatibility. (I believe that it's been demonstrated that the very oldest prototype finder versions that are floating around on the Internet will run on a Plus/Plus-configured emulator.) I'm not sure anyone's definitively named a program that's broken by the 128k ROM itself.

Waiting now for the flood of citations proving otherwise, of course.

 

[napabar]

All said, the 512ke doesn't have much "value" to me (although I would give it more value relative to a 128ke). Ditto for the "ED" model.

I guess "value" is in the eye of the collector. For me, the Plus is worth less than a Mac 512Ke. It was made for almost 5 years (more than any Mac ever) and is not hard to find.

But, primarily, the Plus is much too advanced to make my experiments interesting. I can't believe anybody in the Compact Mac community would find what I did with the Mac 512Ke as interesting if I did them with the Plus. 4 Megs of RAM? SCSI to Ethernet? MacTCP? FTP server (NetPresenz)? System 7.X? AppleShare Server? All of these can be done on a Plus, but not a 512Ke. The challenge was to get this little Mac to do something that it wasn't supposed to be able to do. The Plus is a monster compared to the 512Ke.

 

[napabar]

As for the 128Ke, again, I look at Apple's offerings based on marketing (which is why the Apple II fight on Wiki was so frustrating). Not only was the 128Ke not sold as a package, but it was actually discouraged by Apple, so in my mind it doesn't qualify.

Mac128,

Do you have any documentation on Apple discourging this ROM upgrade? Everything thing I've ever seen (which is very little) from Apple implied that it was an upgrade appropriate for both the 512K and the 128K. It was sold seperately from the Mac Plus upgrade, which was also avaialble to both machines.

 

[JDW]

For me, the Plus is worth less than a Mac 512Ke. It was made for almost 5 years (more than any Mac ever) and is not hard to find.

I agree that other Macs are of more value to me than the Plus. In fact, I don't even own a genuine Plus, although I have the ROMs from one. No, when I searched EBAY for a compact Mac (to replace the Macintosh 128k that I originally owned in 1984 but later sold when I got into college), I passed over the Plus in a heartbeat for the Mac512. Again, the 64k ROMs were the ticket for me. But if one doesn't care about the ROMs, one would do better with a MacSE than a Plus.

 

[Scott Baret]

It all depends on what you want to do with your Mac. The Plus actually is a fun machine to work with because it CAN do so much. How many computers from 1986 can play a CD, post a Tweet, display a dithered desktop picture, and run system software made ten years after it was released with no modifications aside from the RAM upgrade? I actually used a Plus to connect to AOL as late as 2001 and wrote a novel on one for Retrochallenge three years ago, all while listening to my CD collection on it through a SCSI CD drive. I had a dithered photograph as its desktop pattern, utilized multitasking, and printed to a printer made nearly a decade after the machine. (For the record, this machine was running System 6, not 7). Find me another computer introduced in January 1986 that can do that!!!

The 512Ke is obviously far less powerful and is limited by its fixed RAM and lack of SCSI. Still, it is, as others have pointed out, far less common than a Plus. That's not to say interesting things can't be done with 512Kes; someone recently used one to receive a message from Siri. Still, it's considered more of a "historical" machine than the Plus due to its old-fashioned case design and inability to be expanded or run newer software packages. It may not receive as much attention as the original 128K and 512K, but from a hobbyist's point of view, it's actually quite desirable--it's the ultimate original Mac (by original, I mean non-SCSI) and has the far more reliable 800K drive, perfect for those who aren't up for restoring the trouble-prone 400K drives.

The 512Ke also has one of the most rare variants--the platinum edition. These were made in 1987 and appear to be extremely uncommon.

Apple probably didn't update the 512Ke badging because they felt the model wouldn't stick around for long. They knew by April 1986 that they would be releasing two new models within the next year. (In fact, I remember reading they had originally wanted to use the 68020 in the SE). They essentially released the 512Ke as a temporary stopgap model until the Plus could become the low-end machine, but kept it around for another six months afterward, perhaps for educational customers and others on a budget. The IIe Enhanced, meanwhile, was a computer Apple probably felt would be kept around for some time (which it was). Still, the 512Ke had a lifespan of 1 year, 5 months (approximate), and while some computers did receive badging for variations (such as the SE FDHD/SuperDrive), many did not (just by looking at them, it's impossible to tell some models of iMac apart).

 

[JDW]

It all depends on what you want to do with your Mac. The Plus actually is a fun machine to work with because it CAN do so much.

Yes, but as I said in my previous post, if you want something like the Plus (68000 CPU, 128k ROMs, SCSI, lots of RAM, etc.), why buy a Plus over an SE? The SE is the better choice, hands down. It's marginally faster, more expandable, and generally more reliable as well. Back in the day, the Plus was the clear choice because it was CHEAPER than the SE (until they discontinued the Plus), but for us today, I would give more value to the SE.

In my opinion, the only good reason for having a 512ke and/or a Plus would be if you were a collector committed to collecting one of every single "Compact Mac" model Apple ever produced. You would need those models to have a complete set. But other than that, I see value in the 128k because it was the first, value in the 512k because it is the "usable edition" of the 128k memorywise (with the same 64k ROMs), and the SE (for reasons already stated). Of course, the love of my Compact Mac life is the SE/30, but that is in somewhat of a different category because it doesn't have a 68000 CPU.

 

[Mac128]

Do you have any documentation on Apple discourging this ROM upgrade? Everything thing I've ever seen (which is very little) from Apple implied that it was an upgrade appropriate for both the 512K and the 128K. It was sold seperately from the Mac Plus upgrade, which was also avaialble to both machines.

The funny thing is I have never seen ANYTHING that said the ROM upgrade was appropriate for the 128K so I would ask you the same question. The ROM upgrade kit was part of the 800K floppy drive upgrade, afaik, it was not available as a mere ROM upgrade as that would dearest the purpose of Apple offering it - they wanted to get rid of MFS. It also makes no sense to keep offering a 128K with 64K ROMs and 400K drive 6 months after the 512Ke was introduced, since it means maintaining an obsolete file system and an additional set of parts rather than minimizing costs with economy of scale. I could be wrong, but I've never seen it. Also, while an 800K disk will work on a 128K, Apple never officially supported it. I have never seen any documentation indicating compatibility with a 128K which would be odd if they encouraged the ROM upgrade to a 128Ke. Also, the 128K has enough Troy le with the 400K disk directory in the Finder, so eating into the available RAM with the added code from the 128K ROM, plus 800K of data to keep track of (potentially 1600K with an external drive, or 21MB with an HD20, which is also not officially supported by Apple in that configuration).

That said, I believe I recall first reading Apple did not recommend the upgrade in a TIL. I believe it is also absent from the TIL upgrade chart. I may have also seen it in a service manual. I think Pina also mentions this and explains that it can in fact be done in His first repair book. I would check, but all my reference materials are I'm storage at the moment.

Again, I may have inferred this from text, but I can assure you, I have NEVER seen anything recommending this, nor any evidence that it was done. One would think the advantages would be so enticing that stock 128Ks would be non-existent. the 800K drive upgrade was an amazingly reasonable price because Apple was trying to get everybody onto HFS, and e enducement for the consumer was that it was a cheap way to improve performance over original investment with a continued upgrade path for the 512K upgrade, or even the Plus which required the drive kit. Bottom line is, I nor anyone I have ever talked to has ever come across a 128Ke in the wild. This suggests that it was never supported, encouraged or otherwise acted upon, more than it was simply unpopular. After all, anyone who has ever used a 128K will bemoan the lack of disk space over RAM.

But happy to be proven wrong.

 

[napabar]

Oh, wow!

Well, I can tell you they do exist because I had one back in the late 90's! There was a time when I was collecting Mac 128K's, and I had three of them at one time. The last one I bought had been upgraded to a Mac 128Ke. I remember being disappointed at the time when I bought it, because it wasn't in it's original configuration. It had the 800K drive and 128K ROM. Still had only 128K of RAM. HD20 worked fine with it, and it could boot from the HD20.

After awhile, I got out of collecting classic Macs, and I got rid of them. I could kill myself for doing that, because finding another 128Ke is going to be hard.

I have Pina's first book, and he details upgrading a 128K or 512K with the Disk Drive/ROM kit.

 

[napabar]

The 512Ke is obviously far less powerful and is limited by its fixed RAM and lack of SCSI. Still, it is, as others have pointed out, far less common than a Plus. That's not to say interesting things can't be done with 512Kes; someone recently used one to receive a message from Siri.

That was me! :lol:

 

[Rasmus]

With regard to whether it is a mere revision or a different model, the 512Ke has a different model number. It also had its own user manual and Plus-like packaging. If not for the System 3.1 Finder 5.2 bugs, it would have had its own initial OS as well. While I tend to see it as an upgrade to the 512K and not a watered-down Plus, it was also more than just a "peripheral improvement" (as napabar put it) to the 512K -- Apple knew that future development of the OS would require the Mac Plus ROMs. There's a big difference between the 512K and the 512Ke -- the former was Apple's high-end Macintosh for most of its life, while the latter was always a lower-end alternative to the Mac Plus, primarily for students and the education market. To say they are basically the same model ignores both the dramatic changes in both the machine's outlook with regard to future OS developments and its position within Apple's lineup.

With regard to the 800K-disk-drive expansion kit, it's useful to remember that the 128K was discontinued at the time it was released (1986). This explains why, as far as I know, the 128K is not mentioned in any of the Apple materials, like the installation manual and user's guide. Still, any competent dealer or repair person would have known that it could be used on a 128K. I don't know if we can say Apple actively discouraged doing so, but it might be possible to find evidence that Apple trained dealers to encourage 128K owners to get the Mac Plus upgrade as well -- certainly anyone wanting to run software (increasingly common at the time) designed for at least 512K of RAM on their 128K would need to do that. That's why 128Ke machines are so rare in the wild -- most were upgraded to the Plus if they were upgraded at all.

 

[Mac128]

I have Pina's first book, and he details upgrading a 128K or 512K with the Disk Drive/ROM kit.

As I recall Pina approaches the topic as the "official" upgrade of a 512K to a 512Ke. He then approaches upgrading a 128K in this manner under the heading of "Unofficial" upgrades. He then addresses the 128Ke Mac as a viable option despite the fact it is commonly thought not to be possible. This suggests to me Pina is not aware of any "official" practice of upgrading to a 128Ke. If he acknowledges the prevailing belief was that it was not possible, then there could not have been much documentation from Apple publicizing it, or indeed suggesting it, nor dealers recommending it. If someone has access to the Pina book to check this that may help clarify this.

Also, the Apple service Guides I have mention the ROM compatibility with an 800K disk upgrade for a 512K Mac only. Now this may be as Rasmus suggests, because the 128K had been discontinued 3 months before the drive upgrade kit was available, nevertheless, nothing in the service manual explicitly states the existence of an enhanced 128K. It is interesting to note, the 128K was discontinued just as the first Apple II 800K Unidisk drive was introduced alongside the HD20.

I recall too that the original Mac Bible details the upgrade path and specifically states that the 128K ROMs & 800K drive require a minimum of 512K RAM. Obviously incorrect, but where did that assumption come from if not Apple?

So the general view I have from first hand accounts at the time, it appears as though the 128Ke was neither supported or encouraged by Apple. Again, there does not seem to be any concrete evidence either way, and I honestly don't recall where I remember reading that it was not recommended for 128K Macs. So until something surfaces that suggests otherwise, I have to maintain that it was never "officially" supported by Apple, if for no other reason than it was for a 3 month previously discontinued Mac that was likely never tested internally, and could presumably cause more problems than it would solve for the customer considering the limited RAM. I mean imagine the disk swapping issues alone with 800K considering how trying it was with 400K. There is some precedence for this as Apple released the 3.5" Drive in September '86 which states it is compatible with both the 512K & 512Ke. However, there is a notable bug on the 512K which is it constantly resets unless a disk is inserted. Moreover, it works fine on a 128K, with the notable exception that you cannot format an MFS disk on it, however, it will readily read/write 800K formatted MFS disks made on another Mac. But has no problame with 400K disks. Now considering this was the only external drive option available for the 512K or 128K, one would think Apple would have also included the 128K on the list of compatible Macs, except it was probably more trouble than it was worth considering it's limitations. And frankly, I just don't see Apple encouraging the continued use of the 128K under any circumstances, short of upgrading it to a 512Ke or Plus. Jobs and Sculley made a mistake of limiting it to 128K and by 1986 Apple must have realized that continuing to support it would not help the reputation of the Mac in those early days.

 

[Gorgonops]

Regarding the discussion about the desirability of the Mac Plus vs. The SE: at the time when both were "real computers" the SE is clearly a superior machine. HOWEVER in a collecting context if I had any interest in owning a compact Mac I'd personally much rather have a Plus for one reason: it's the newest model that (800k drive aside) is 100% hardware compatible with the original Mac. As noted earlier, a Mac Plus is basically capable of running even the oldest (non-copy protected) software in circulation. I'm *pretty sure* with the SE its ADB keyboard and mouse trips up some things. However, as an owner of neither I can't say that definitely. The Plus also has the advantage of *looking* like the original Mac. I'm sure there is room for debate as to which is "better" but the SE is obviously newer.

As for the 128ke question, I seem to recall that the Plus rom's leave about 1.5k less free memory (regardless of System version) available. That's not a big deal with 512k but if you read Folklore's recollections of just how tightly constrained programs like MacWrite were on the 128k it could well make the difference between something running or not.

I have to wonder actually if most "128ke" machines in the wild are they way the are because they were at some point fitted with combo memory/SCSI/accelerator cards that were subsequently removed and sold separately.

 

[JDW]

Regarding the discussion about the desirability of the Mac Plus vs. The SE: at the time when both were "real computers" the SE is clearly a superior machine. HOWEVER in a collecting context if I had any interest in owning a compact Mac I'd personally much rather have a Plus for one reason: it's the newest model that (800k drive aside) is 100% hardware compatible with the original Mac. As noted earlier, a Mac Plus is basically capable of running even the oldest (non-copy protected) software in circulation. I'm *pretty sure* with the SE its ADB keyboard and mouse trips up some things. However, as an owner of neither I can't say that definitely. The Plus also has the advantage of *looking* like the original Mac. I'm sure there is room for debate as to which is "better" but the SE is obviously newer.

Looks do play a role in my vintage Mac ideology, which is why I've never lusted after a Color Classic. It may sound silly, but had Apple come out with a color "SE" or color "Plus" I might have found it more appealing. It's something about that protruding part on the front above the CRT that never sat well with me.

As to the Plus vs. SE in terms of "software compatibility," the key to that discussion is what you just said: "Plus is basically capable of running even the oldest NON-PROTECTED software." So if we exclude the protected software, what are we talking about in terms of overall percentages? And if that excluded software is a sizable percentage, what advantage then does a Plus really have over the SE (other than looks in some people's minds, or for "collector's value")? To determine that, it would be good for us to research how much software is and isn't compatible with the Plus, and then do the same for the SE. If the results are largely the same in terms of "percent incompatible" for either model, then the nod would go to the SE for (a) marginally higher performance, ( B) a better power supply and analog board, © expandability. There is of course "fan noise" in the SE which is not present in the Plus. However, I would do an upgrade on the SE just like I did on my SE/30, and swap out the stock fan for a near silent cooling fan.

 

[Mac128]

I have to wonder actually if most "128ke" machines in the wild are they way the are because they were at some point fitted with combo memory/SCSI/accelerator cards that were subsequently removed and sold separately.

Pina actually makes this point when debunking the popular notion that the 128K could not be ROM upgraded. He indicates that following the 800K drive upgrade, a 128Ke can then be easily upgraded to a 512Ke or greater with a clip on SCSI combo board, rather than go through the physical memory upgrade he previously details in the book.

But like you, when I mentioned earlier that I didn't think the 128K could truly support the upgraded ROMs, I was thinking of this tight RAM constraint u mention as discussed on Folklore. While this might not affect every program run on the 128Ke, surely it must affect some. And I just don't see Apple running the risk of selling it for this purpose when potential untested problems loomed out there ...

As for the SE, there is a lot of vintage software that makes it a minimum requirement or some reason. The Zip Tools software comes to mind. It still supplies a PWM for a 400K drive, so I hadn't really considered that the ADB keyboard and mouse might otherwise trip things up. There's also new video and SCSI hardware implementation. I don't recall what the earliest software you can run on the SE, but I seem to recall it will not run System 1.0, possibly even 1.1, while the Plus is only restricted from running System .85 on the demo.

Still, considering how many overall improvements the SE offers, how much does one really sacrifice running earlier software? Don't get me wrong, I'm not a fan of Frogdesign's retooled Mac, and prefer the Plus any day. It just seems that if you have one Compact, the SE provides a much wider bridge of compatibility with a broader range of software than the plus.

 

[trag]

Regarding preferring a Plus over a 512KE:

The 512KE will run Megaroids. The Plus won't. This is the one reason I can see to prefer a 512KE.

Apparently it's something to do with the memory installed and not the ROMs. I've never tried Megaroids on a Plus with two 256K SIMMs installed though. That would be an interesting experiment.

Megaroids also doesn't run on my 512KE with NewLife upgrade installed. All the NewLife upgrade does is up the memory and provide a SCSI port. It uses a 68000 CPU at the original clock speed. So again, it's probably either the greater memory, or maybe the presence of the SCSI port -- although that seems a little unlikely.

 

[JDW]

The 512KE will run Megaroids. The Plus won't. This is the one reason I can see to prefer a 512KE.

And although I've long forgotten which 64k-ROM compatible programs became incompatible under the 128k ROMs, that is my reason for liking the original Mac512 over the 512ke!

It certainly would be nice if we had a comprehensive list of software incompatibilities between among the 128k/512k and 512ke and Plus and SE (all the 8MHz 68000 CPU compact Macs).

 

[QuicksilverMac2001]

"Mac128 wrote:

"Bottom line is, I nor anyone I have ever talked to has ever come across a 128Ke in the wild. This suggests that it was never supported, encouraged or otherwise acted upon, more than it was simply unpopular. After all, anyone who has ever used a 128K will bemoan the lack of disk space over RAM.

But happy to be proven wrong."

Well, I can't say that I have a 128Ke, but I can say that for my humble purposes System 1.1 Finder 1.1g with MacWrite 1.5 and MacPaint 2.2 is everything I need it to be, and the only reason why I wanted an external floppy drive for it was to prevent the 400KB original drive from wearing out. I couldn't tell any real wear on my arms from disk swapping, and if there was any, I could use the exercise anyway.

And this is with the 64KB ROMs that it originally shipped with, and the 128k version of the 128k/512k combo board, and with the stock 400KB internal floppy drive and stock amount of memory-but to be completely fair and brutally honest it DOES have the optional 400KB external floppy drive, which was bought as I said more to prevent the internal drive from wearing out than to save any effort (aside from otherwise having to risk having to buy a replacement floppy drive) on my part.

The 128k may be what some would call ridiculously spartan with MacWrite 1.5 and MacPaint 2.2 and TeachText running on System 1.1 Finder 1.1g with the 64KB ROMs, 128k of RAM (checked it using System 2.0 Finder 4.1, and even dual 400KB floppy drives, but with one floppy holding the system and the three applications I might really want to use, and the other to save my documents too, I never really can complain that I run out of space. At least until all the available floppy disks for document storage have been filled up.)

Apple really did an amazing thing with the 128k ifeyou care to use it as intended or give it a Plus or Plus-equivalency upgrade if you want real performance. I had simple tasks I needed a Compact Mac to do, and a 128k with my given software and hardware does it all.

Not to say that you are wrong at all, but my perception of the 128k (at least with what I do with it, and given that I don't have a 128Ke) is just what it is, and from my perspective you were proven wrong at least in regard to a truly stock 128k.

I do agree wholeheartedly that a 128Ke might be nice for experiments, but why kill a Plus, 512Ke, etc. to get the necessary ROM chips?

Just an observation based on listening and personal experience.