this seems to be a ROM for a later Unitron clone, the "Unitron 1024" which work was started on after the US govt threatened and forced the shutdown of the "Mac 512" project. supposedly the Unitron 1024 wasn't going to look like a macintosh, in an attempt to appease the government, but it also got shut down regardless

the Mac 512 was shut down not because the case looked like a mac, not because the analog board was a carbon copy, but because the unit that Apple somehow managed to investigate for themselves during development contained a copied Mac Plus ROM. however, Unitron's argument was that that was only being used for development purposes and the retail version would contain a reverse engineered rom. at the time, there was no law against that in brazil

this is a screenshot that i believe to be from the Mac 512 retail ROM (it says "Insert the initialization disk" in Portuguese). in trying to locate this ROM (the only known dumped Mac 512 ROM is actually the Mac Plus copy) i accidentally found the Unitron 1024's instead.

i can only find the "Unitron 1024" mentioned online in two places:

one is in a posthumous legal study of the Mac 512 case in which it's mentioned as an addendum

the other is a supposed MAME driver for which any rom i've found are just... mac plus roms.

development documents. this mentions the rom is for both models ("Mac512/Unitron 1024") but i don't think the sources in them are complete

the source i found has several floppy images, but also some folders that seem to be from different floppy images destructively extracted into a FAT type system so some of it might be lost

i actually found two roms, one larger than the other, but so far i can only get the second one to do this

i wanted to investigate these more before uploading them but i lost interest. here they are

it looks like they're (at least partially) compiled from C(?), not sure how complete they are, not sure how much of them are still just copied from apple roms. both have the same build date, smaller one seems to boot and the larger one just sadmacs. functionally the only difference i could see are graphics. the sources are as far as we know completely lost.

https://netizen.club/~maple/files/unitron

#apple #macintosh

the only other known dump of a Unitron Mac 512 ROM is the earliest one, which is identical to the Mac Plus ROM, which caused the Apple lawsuit which shut down the project. had Unitron not rushed to market before they could've made a clean room clone of the ROM (which the eventual Unitron 1024 tried to, too little too late), the Mac 512 project might have passed certification (necessary to be sold) and survived.

some misconceptions: Unitron did not work on multiple mac clones, it only changed name:

"Mac 512" is the initial project, which was simply a straight up copy of the original Macintosh with 512K RAM, eventually became closer to a Mac Plus clone

"Turbo Mac" is the same identical machine with improved PAL timings for RAM access which sped it up

"Unitron 1024" is the same hardware with 1MB RAM, in a futile attempt to make it more legally distinct after the lawsuit

none of it fully came to market

@mavica_again I'm going to have to reconsider my avatar on here

@mavica_again This is awesome, thank you so much for finding these, investigating them and sharing!! :D

@mavica_again Thanks so much for sharing these-- I did a comparison of the earlier Unitron ROM a few years ago: https://twitter.com/ablitter/status/1377166564466728967

Looking forward to diving deep into these!

(BTW, RomUnit is 404ing 😞 )

@blitter sorry about that, my nginx path solving was unhappy with files without extension -- should work now

@mavica_again I see a bunch of stuff pull up on DuckDuckGo and google?

@colinstu these?

@mavica_again ah, took "two" as literally two results.

@DosFox i found it online in an archive of some disks dumped some 20 years ago that just went overlooked. a bunch of the discs contain personal information including MacVision scans of photos of probably someone's kids. i'm trying to dissect this further with some people more familiar to it (i've found who had the disks originally) before i post files

@DosFox but, if your google-fu is good enough, you'll find it just as i did. all my work here so far was internet sleuthing and being natively Brazilian.

@mavica_again ah Sheesh, if there's anything that looks like other Unitron documentation - let me know.

@DosFox unfortunately the disks were badly damaged (full of mold, 20 years ago) and the stuff that was more interesting (source code, documentation) might be all gone. the ones that survived were mostly disks used well after Unitron's dissolution by family members, personal files and copied retail software from the US

@mavica_again ah - nothing that looks like PAL equations? 😅

@DosFox those were contracted out to Jecel:

http://www.merlintec.com/lsi/mac512.html
http://www.merlintec.com/download/unitronreport2and3.txt

@mavica_again actually they weren't.

That was the "turbo Mac" project which were separate to the original PALs

@DosFox far as i understand, Unitron only had one Mac project, the Mac512 which later evolved into Unitron 1024. the PALs were meant to go on these machines, but the project got shut down. Mac512 was supposed to be the "turbo" one, there was no other model

@DosFox beyond that, Unitron just reverse-engineered the Fat Mac down to a tee. the only thing they developed independently was this ROM that might not even be finished.

@DosFox Jecel was contracted because he offered to make it faster. This was all one project, not multiple.

@DosFox The Mac512 never properly released. Unitron offered sales before SEI (the agency that allowed sales of microcomputers at the time) granted them the possibility, landing them in hot waters aside from the whole Apple lawsuit. Production numbers of 200 to 500 have been spoken of but I highly doubt those. By 1988 the "Mac512/Unitron 1024" was still "in development". even a 200 production number would've yielded more surviving units than we have today (which i think are only 2-3 confirmed)

@DosFox for example the Unitron 1024 was brought on because of the Mac512 getting shut down from the lawsuit, and one of the ways they tried to make it work was remaking the whole case into something that didn't resemble the Macintosh. The only source i can find for that is worded to mean that this was already accomplished and presented to SEI, but nobody I've talked to has ever seen such case, some didn't even know about the attempt to save the project

@DosFox re-reading Jecel's retelling i can understand how this might be confusing: what he's referring to as the "Turbo Mac project" is just Mac512. they were still developing it and this would improve that project, the less Apple material they could release it with the better. the "Mac with separate monitor" he mentions was likely an early Unitron 1024.

@mavica_again
The Unitron 512 was launched in 1985.
Jecel became involved in 1987:

http://www.merlintec.com/lsi/mac512.html

As far as I know Unitron 512s existed as a commercial product

@DosFox I can tell you the Mac512 project was never legally commercially available. SEI never approved the project. And I'm actually in Brazil, so.

@mavica_again I've been in contact with Jecel before, we could ask him!

@DosFox He says himself that in the 1985 fair their clones aren't even functional. We can rely on his memory, sure.

@DosFox or we can rely on the legal study from 2003 which has sources mentioning that the case was stuck with SEI until march 1988 https://www.abphe.org.br/arquivos/2003_ivan_costa_marques_caso-unitron-e-condicoes-de-inovacao-tecnologica-no-brasil.pdf

@DosFox the technical study of the Mac512 to determine its legality wasn't even ordered until 1987. it never went to market, it would've been illegal for it to do so. Unitron posted ads in early 1988 and SEI shut the project down.

@mavica_again
I'm happy to be wrong about if the Unitron 512 was ever legally for sale - my original point is that the Unitron 512 worked before Jecel was brought on, meaning Unitron used other PAL equations - which I wouldn't mind having a look at!

@DosFox Jecel says it himself in his page they're just copies of the Apple PALs.

@mavica_again we can rely on his memory, sure ;)

Joking aside - even then a full set of equations for the PALs don't exist at the moment. Wondering if there was another lead!