Mac ROM-Inator II Restock and Partnerships | Hacker News Reader

Mac ROM-Inator II Restock and Partnerships

bigmessowires.com

70 pointselectricant29 comments

Modifiable ROM images let us do all sorts of things like add support for more memory via higher density SIMMs (Quadra / Centris 610, 650, 800), add support for non-native and not normally supported hardware, fixing bugs, and so on.

I'm considering getting one so I can have a low power, boots-straight-into-use LocalTalk to ethernet bridge with print drivers and printer sharing. Another option is network booting, since network file sharing is so incredibly easy with classic Macs.

Fun!

Apple liked to artificially cripple their machines in the ROM. I had a Mac LC as a kid that was limited to 10MB of memory because otherwise it might affect sales of the Mac II Ci. Being able to remove these artificial limits is great.

Not to say there has never been software based market segmentation, but this example is just not right.

First off the LC was in no way a threat to the Iici. The IIci had 32 bit data bus with a 25MHz 68030 and and supported a CPU cache. The LC with a 16MHz 68020 with a 16 bit bus. The Iici was conservatively twice as fast.

Second, the LC HW did not support nearly as much ram as the Iici. It shipped with 2MB soldered down (which logically you can think of 2 1MB SIMMs) and had 2 slots that each supported 4MB SIMMs, which were the highest density commonly available at the time. The (cheaper) memory controller used in the LC only supported 24 bits of physical addresses (and only in so many configurations), resulting in a maximum of ~16MB. Once you account for the soldered down two megabytes and how the slots had to be configured that left you with the ability to install 4MB into the each slot you get 10MB.

Technically speaking it was probably possible to get it to support 12MB or 16MB with a ROM patch if you desoldered the builtin memory and soldered from the address lines on the controller to some custom memory board. But as shipped with the builtin RAM and the controller chip they included 10MB was the most it could reasonably use.

The LCII did up the builtin memory to 4MB and had a software limit of 10MB like the LC (which meant if you installed 4MB SIMMs you would be missing 2MB), but I suspect that was more a result of how quickly it came to market (it was essentially just an LC with a 68030 and 4MB of ram, both of which greatly improved the experience of using the machine with System 7, which shipped after the original Mac LC).

Within a year or so after the LCII the the LCIII shipped with a completely redesigned board, and it supported 36MB of ram.

Source: I owned a Mac LC, paid for and installed a 2Mb memory upgrade to get it to 4MB, then eventually did a motherboard swap to upgrade it to an LCIII. I can even still tell you how much each of those upgrades cost ;-)

I was being a bit tongue in cheek about Apple saving the IIci. But the ROM on the machine is hardwired to only support up to 10MB of memory, even if you drop in larger sticks that would otherwise be supported. There's no real reason to do this except to protect the higher priced products. But as you noted, there wasn't really a higher end product to protect because the LC was already crippled by its slow bus and obsolete CPU.

I think you missed my point. It wasn’t just ROM limited, the ram controller they used in the LC did not have enough address lines to address more than 4MB per SIMM slot, end of story. No amount of firmware hacking can ever make it support 16MB SIMMs without what amounts to a total board redesign. Given the 2MB soldered to the board (which took the address lines for two of the slots) that meant the machine was physically limited to 10MB unless you wanted to break out a soldering iron. Yes, the ROM has a software limit, but it reflected the actual limits of the HW (and more likely was due how the ROM went about detecting the ram then any explicit intent to limit things… it is not shocking that the software only works with supported physical configurations and not board reworks).

The LCII on the other hand is a bit less excusable since it could physically hold 12MB but only 10 was usable. As I said I suspect the reason is that it was a fairly quick revision they squeezes in before the redesigned LCIII and they just didn’t rev those parts of the ROM, but it still seemed pretty bad).

If you want more info there is a pretty deep dive on this here: https://68kmla.org/bb/index.php?threads/technical-explanatio...

One interesting thing I've discovered recently is that everyone (including myself) is doing the ROM SIMM pinout slightly wrong when used in Quadras. The existing programmable SIMMs seem to work in the 610/650/800 and 700/900/950, but I think the onboard ROMs aren't being properly disabled, as someone discovered when trying one in an LC 475. I'm probably going to write a blog post about the topic soon.

Also, some exciting news is that ROM disk hacks are definitely on the way for the Quadras. It's possible to unlock the full 8 MB of ROM space in several of the Quadras. I've seen video of a Quadra booting from a 7 MB ROM disk. Too bad most of them after the 700/900/950 don't have the socket populated :-( The pads are there at least, for people who dare to add it themselves...

I have used the Floppy-EMU from BMOW and it was incredibly powerful I was able to emulate hardrives and floppies on both Apple II and Macintosh Plus that I own. Glad to see this guy is still making new products for the retrocomputing community!

What I don't get is why you'd ever want floppy-emu when you can use scsi2sd (for the Plus)?

The problem I have had with just a SCSI2SD for my plus is that mini vMac doesn't support partitioned disks. So to bootstrap I had to

1: write a disk tools disk using a greaseweazel 2: Boot the Plus and set up the partition etc 3: carve out just the partition to a disk image using dd 4: attach the resulting disk image to vMac, set everything up how I wanted it 5: copy the disk image back into its partition using dd

Thanks for this!

A somewhat-unsung feature that a custom ROM can give is HD20 support – essentially, a hard drive that connect to a Mac's external floppy port, without having to worry about the complexities of SCSI. I believe it can actually be hot-swapped as well.

Nice. I've got the ethernet card for my SE/30, and I always meant to upgrade it to 128 megs of ram. Maybe I should get this.

I have a SE/30 with a Mac ROM-Inator II in it, and the ROM boot image has been really nice. Since I installed it I've never needed a floppy, so that's a plus. I have used the ROM boot a few times, it's handy once you've got it.

I also have a ZuluSCSI SD<->SCSI adapter in the SE/30, and it's made the machine a lot more fun to play with. I set up the drive images in an emulator and then moved the images to the SD card and booted to them. It's booting A/UX now, and it was easy with no floppies and no SCSI CD drive.

At this point in time the retrocomputing community has built a lot of amazing hardware to grant new abilities to old computers.

Know of any that would let it play MP3s?

I was always under the impression that you could mangle things and get two (more?) PDS cards in one. I had hoped at the time I could maybe even ditch the crt and get an Xceed to do internal video on some LCD for it.

You should.

Wow this looks amazing.

> Friendly competition is great, but it creates a potential dilemma for me if someone buys another vendor’s ROM SIMM and reprograms it with BMOW’s base ROM in order to get the on-the-fly ROM disk decompression and other features. It could turn into a situation where my base ROM software is subsidizing another competing product. To compound the problem, I didn’t have any clear usage policy or “license” for the base ROM to say whether this type of use was OK. Furthermore my FC8 compression algorithm is free open-source, but the BMOW base ROM which incorporates it is not. This all created a large gray area.

Imagine thinking that copyright should protect your revenue stream that is based on making tools for infringing the copyrights of others.

Admittedly the thing they're making unauthorized derivative works from (the Mac ROM) is abandonware, but the idea is still silly and hypocritical to me. Copyrights are ridiculous to begin with, ignoring them in one case while trying to wield them against your community in another is extra ridiculous.

I am also opposed to "paying to pirate" but that's not how I see this situation. He has added significant value over the original Mac ROM and that's what he's charging for. Acting like nobody's allowed to make money hurts communities.

> He has added significant value over the original Mac ROM and that's what he's charging for.

Has he though? It sounds like it’s all based on Apple’s work decades ago plus an open source compression algorithm that someone else wrote.

There’s also the physical hardware of the device itself. He wants $45, which seems quite reasonable for a custom SIMM with flash memory.

He’s also not restricting the use of his or Apple’s software, so he’s not making any claim, copyright or otherwise.

So he makes the PCBs, loads them up and tests them, then sends them off to the purchaser, all for $45.

Yes, that sounds like a significant value.

>Has he though?

Yes. ROM-booting was something Apple supported in the Mac Classic and no other model. The ROM adds new functionality that wasn't available to the SE/30 (and others). It also adds the ability to boot of a modifiable RAM disk, which is new. Also it's 32 bit clean, unlike Apple's ROMs. So this fixes Apple's bugs as well as adding new abilities to a few models of Macs that they never had. The ROM-booting is facilitated by compression, but putting together a bootable ROM for hardware that's never done it before to ROM-boot off the compressed system image is the hard part, not the compression. Much of that is based on the hard work of Rob Braun, Doug Brown, and others who are credited.

He put a lot of work into this, the thing he made wasn't an existent thing in the world until he did the labor and he documented how to do it for those who want to burn their own. He ships a ROM SIMM with the new image burned on it for $45, given that the ROM SIMM itself isn't free, the whole deal seems fair to me.

The creator has also been involved in Floppy Emu. He's done a ton to help revitalize retrocomputing. Begrudging him selling a ROM image he worked to make is an incredibly toxic take on a person doing really excellent things and sharing the technical details for anyone who want to build the stuff themselves.

You've convinced me. If I'm ever in the market for one of these, I'll buy from him to support his work.

This is an unauthorized derivative work. He is not entitled to make any money for it without Apple's consent under current copyright law.

It's the same as you, being not-Disney, making a sequel to a Disney movie and putting it in theaters.

Then he turns around and tries to indicate that it's wrong for others to profit from derivative works based on his efforts.

Either copyright law is just and valid, or it isn't.

Either what his competitors are doing with his work is wrong and bad (as he seems to think it is), and his modification of Apple copyrighted material is also wrong and bad, or what he's doing is okay, which also makes what his competitors are doing okay.

> … trying to wield them against your community in another is extra ridiculous.

Also, ineffective. What’s he going to do if the copycats don’t stop, sue them?

Who's wielding anything? Your quote oddly omits the very next sentence, where he makes said ROM image 'explicitly free for personal use' with any hardware you feel like using it on.

Which strongly implies that he believes he can restrict their commercial use, which is false, as they are themselves unauthorized derivative works of a copyrighted work.

Everyone involved here is pirating the ROM.

One thing I find interesting is the "please don't back this up" mentality of some of the older gray area content.

I get it, you don't want (bigcorp, chinese clones, etc) causing you problems. But when you die, what happens? Who's going to be there to pick up the parts?

I feel like so many things should get hucked right onto Internet Archive as soon as someone says "please, no, don't" just out of pure self preservation.

Definitely.

Archiving wouldn't go anywhere if we didn't ignore individuals for the benefit of humanity as a whole.

By all means, back it all up.

I do wonder what the tail end of this looks like.

Eventually the whole operation is just going to service a few odd museum pieces. The Macintosh II will sit alongside the Linotype machine, the Jaquard loom, the Watt steam engine, etc. The question is what you do between now and then.

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