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Mac Rom Enhancer - Any idea what it did?

Posted by: olePigeon on 2019-05-02 09:53:07 Any idea what this ROM Enhancer did?  It's already a Mac Plus and has SCSI, so it's not a regular ROM upgrade from a 512k. https://www.ebay.com/itm/Apple-Macintosh-Plus-Mainboard-With-Bios-Enhancer/254216481732

Posted by: Dog Cow on 2019-05-02 11:16:57 Oh, you saw that too? I saw that last evening and was wondering the same thing. In MacUser March 1986, I found a listing for Micah ROM Enhancement. No idea if this is the same thing, though. Discussion of Micah and Micahdrive (it's near the top of this digest posting). Not sure if there's a connection, but they mention an internal ROM.

Posted by: trag on 2019-05-02 17:51:07 I can't find it listed in my inventory (probably just blind) but I know I bought a Mac Plus ROM kit one time that added RAM Disk functionality.  Sort of like have RAMDiskPlus in ROM instead of as a utility or desk accessory.  I also can't remember what it was called.

Posted by: Trash80toHP_Mini on 2019-05-04 15:57:56 That would be installing your System on the EPROMs to get access to it off the FDD/SCSI interface bottlenecks? If you didn't have a SCSI drive that would be a big Plus. Additional pics are MIA, did anyone snag em while they were up? I just pulled down the main pic. Haven't seen an example of the sanded IC ploy in quite some time. I guess not all that many folks knew about IC testers in the day? [😛]

Posted by: IlikeTech on 2019-05-05 06:59:05 I doubt that kit has a system on it.  It only adds an additional 32K of ROM!

Posted by: Trash80toHP_Mini on 2019-05-05 11:11:40 I was thinking it had 64, but no system probably makes sense in any case.

Posted by: IlikeTech on 2019-05-06 19:34:18 The two 27128 EPROMs add up to 32k of storage in addition to the stock Apple ROMs which are installed on it.

Posted by: Trash80toHP_Mini on 2019-05-06 20:24:41 I was just surprised there weren't at least 256k chips on there if not 512k parts (x8)

Posted by: Yekuku on 2024-04-30 13:48:15 Sorry for bumping this old thread, I just noticed that I have this card installed in my 512K. Did anybody figure out what does it do ? Here is a pic:

Posted by: Iesca on 2024-04-30 14:14:11 This may or may not be related, but this is what I found with a cursory search on Wayback: It seems there was a memory upgrade called "Brainstorm" (seemingly unrelated to the accelerator) that came with a so-called "ROM Enhancer" that allowed you to switch back and forth between the full memory allotment and 512k (presumably for compatibility reasons). Perhaps this is related?

Posted by: Yekuku on 2024-04-30 14:41:24 many thanks for posting this 😉 It confuses me even more. So is it an 1mb upgrade for the 512k? I dont see any added memory chips. Why should anybody use the rom enhancer to switch back to 512K? Also what on earth are they talking about a custom power saver chip ? are they talking about the sanded IC? lol !

Posted by: Iesca on 2024-04-30 14:44:55 If I had to guess, it is one of several boards that would have been installed, but on its own the ROM Enhancer is probably not too useful (if this is in fact the same "ROM Enhancer" that you have). As for switching back to 512k RAM, I imagine the ability to switch had less to do with the RAM itself and more to do with whether you were using the 64k or 128k ROM; some very early software for the 128k/512k Macs were incompatible with the newer 128k ROM introduced with the Plus and the 512ke.

Posted by: Yekuku on 2024-04-30 15:39:08 thanks for the info. I noticed that I have a 800 floppy although it is the 512k model , could it be some rom tweak to accept a 800 floppy?

Posted by: Iesca on 2024-04-30 15:42:48 It would only have been necessary to swap out the original 64k ROMs for the newer 128k ROMs in order to add compatibility with the 800k floppy drive, but perhaps they still wanted to be able to switch back and forth between ROM versions for compatibility's sake? That would be my best guess. The 64k ROM limits you to MFS and 400k disks, but they may have needed it for some technical reason (or maybe they also had an HD20, whose boot disk patches the 64k ROM at boot time to accept HFS disks).

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