Mac Rescue 128K Upgrade Board

[RandomDamage]

Hi,

I just picked up a Mac 128K with a Mac Rescue upgrade installed. From what I understand, this upgrade adds a SCSI port, allows up to 4MB of RAM, AND supposedly provides up to a 2MB RAM disk.

The original 64K ROMs have been swapped out for 128K ROMs, and the internal floppy has been upgraded to the 800K version. I wasn't able to boot from the internal floppy (probably dirty or dead, at least it ejects) but was able to boot up of an external 800K floppy drive.

The SCSI port has been installed in the battery cover area.

My version has 1MB installed, but it appears to take standard 30pin SIMMs. There are a total of six slots, with four currently occupied by 256KB SIMMs. I'm guessing the two empty slots are for the RAM disk?

Has anyone ever used one of these upgrades? Are these at all rare?

-RD

 

[JDW]

I'd love to see a hi-rez photo of your board (1024px wide on Flickr, or 1600px wide on Picasa).

 

[Moofo]

It seems to me like a NewLife Accelerator.

I will sell one on ebay this week...

 

[slomacuser]

it is probably Dove MacSnap Expansion

http://www.vintagemacworld.com/macsnap.html

I have this board in 512k mac with orig. manuals

 

[JDW]

A mere photo would eliminate guesswork and speculation (and make me personally feel better).

Please post a photo!

 

[RandomDamage]

This upgrade appears to be professionally installed. There is a DIP socket soldered directly onto the 68000 pins on the logic board. The upgrade then plugs directly into the socket.

I posted a web gallery at:

http://gallery.mac.com/baakre#100008&bgcolor=black

-RD

 

[kreats]

Nope that's a dove macrescue - I've got one but it was attached by the highly unreliable "killy clip" method (piggy backs over the 68000 & steals the data lines).

You know I was never sure how to get a ramdisk going with it? Haven't used it for a while anyway.

The sad thing is, that nobody is going to ruin their 128k mac by using this nowadays - maybe a 512ke perhaps - but you're really just turning it into a plus, so why not just use a plus straight up?

 

[Mac128]

Couple of observations:

1. It appears as though the connector is soldered into the pin holes on the logicboard with the 68000 chip (and quite cleanly I might add). If so this is an excellent upgrade vs. kreats "Killy clip" reference. I also take exception that this upgrade "Ruins it" since one should be able to install it without soldering anything. (although somewhat unreliable, does your clip-on board not work, kreats?)

2. The presence of a minimux board next to the 68000 chip indicates that the 128K LB was first upgraded to 512K. The RAM chips are 256 variety so that pretty much confirms it. In addition it has the recommended resistor upgrade seen near the mouse port. All professionally done BTW.

3. I wonder if the 512K RAM upgrade is required in order to get up to 4MB. You say your Mac reports only 1MB RAM? If so, this indicates that the board bypasses the logicboard, otherwise you'd have 1.5 MB. You should stick some 256K SIMMs in those empty slots and see what happens. If it is designed to be a RAM disk I would imagine that it requires custom software since the Mac System RAM cache wouldn't know how to use dedicated RAM locations. In which case your Mac won't see the extra RAM. Typically a RAM disk is a cache carved out of total RAM by the System. If merely extra RAM slots, the total with 6 sticks of 256K would be 2MB with the logicboard 512K. 512K sticks would be 3.5 MB and 6.5 MB w/1 MB sticks. Curious. What does the Mac show booting without the board installed?

4. This appears to be a classic upgrade of a 128K to a Mac Plus, the final step in its evolution being a third party board rather than Apple's Plus kit. Which fortunately preserved the bucket. Though not as pretty, the board is restorable to 128K by simply removing the minimux (despite the 512K RAM it should only acknowledge 128K). No need to remove the clip. It also looks very professional so the voltages were likely adjusted to accommodate the extra power draw. However, I would bet the analogue board has nevertheless been repaired or replaced a few times. I also see no reason why the 128K ROM is absolutely necessary, since the SCSI capability is built-into the ad-on board (unlike others onto which the ROMs piggybacked the SCSI board. However, it may rely on the SCSI routines only present in the 128K ROMs. Would be fun to know ...

 

[JDW]

Mac128 raises an excellent point, and one that I have often wondered about. Namely, can you run the stock 64k ROMs on a Mac 128k or 512k and then add SCSI (with the help of the HD20 init) and/or 1~4MB of RAM?

Why would you want to do this? Because some software is compatible with the 64k ROMs and not the 128k ROMs.

 

[kreats]

The killy clip on mine disintegrated over time - had to solder it on in the end. But they notoriously popped off at random times after you moved your mac around. So working.. hmm maybe but with caveats.

Yeah I'm not sure the macrescue board works on a 128k (I used it in a 512ke).. think you need a 512k (or the roms from one) for it.

There's "restorable" and "collectable". Soldering and collectable are a nono. Just try to source a 128k board instead I say.

 

[Charlieman]

Mac128 raises an excellent point, and one that I have often wondered about. Namely, can you run the stock 64k ROMs on a Mac 128k or 512k and then add SCSI (with the help of the HD20 init) and/or 1~4MB of RAM?

Yes. SCSI on a Mac was available before Apple made the Plus. Search Google groups for "John Bass" & Mac & SCSI. I'm pretty sure that there was also a third party board for the 128K and 512K that worked with both 64KB and 128KB ROMs.

 

[Mac128]

What about this one? Seems of the same variety ...

http://68kmla.org/forums/viewtopic.php?p=38627#38627

 

[JDW]

I'm pretty sure that there was also a third party board for the 128K and 512K that worked with both 64KB and 128KB ROMs.

If memory serves me correctly, the "New Life" upgrade that Mac128 indirectly links to is not one of them -- it too requires 128k ROMs. So locating a "64k ROM compatible" upgrade for the 128/512 will be a real find indeed!

 

[Aoresteen]

I have a Mac Rescue board in my 128k Mac. It does require the 128K ROMS.

It will take up to 6 MB of RAM. I have mine filled with 6 MB. The upper 2 MB are used for a RAM disk only. I have the Ram Disk software that address the extra 2 MB. I load the system to the RAM disk and it speeds thigns up quite nicely.

The on-board ram is disabled. I did my own upgrade to 512k.

The bad news is that I'm deployed to Iraq and do not have access to my old Macs & software right now. I'll be back in July so if someones needs the RAM disk software I can provide it in July.

I bought my 128K Mac in June of 1984 and will never sell it! It's still running strong - 800K floppy, 128K ROMS, 2 gig SCSI harddrive ect.

BTW, I was registered on this board a year ago but lost my password and couldn't find my user ID.

 

[gobabushka]

BTW, I was registered on this board a year ago but lost my password and couldn't find my user ID.

Ahh, I see u haven't heard of the great crash of 2007! We lost the whole forum!

 

[Aoresteen]

BTW, I was registered on this board a year ago but lost my password and couldn't find my user ID.

Ahh, I see u haven't heard of the great crash of 2007! We lost the whole forum!

Yikes!!! That is terrible! I've been very busy since Dec 2006 as the Army recalled me, I moved from Orlando to Atlanta, and deployed to Iraq May of 07. I'm just now catching my breath.

Sorry to learn about the crash. Thanks for filling me in.

 

[Charlieman]

SCSI drive kit that claimed to work with 64KB ROMs:

MicahDrive AT -- for 512K and Plus. The drive firmware supported HFS with Plus ROMs or MFS with 64KB ROMs.

For confirmation, search Google groups for "Delphi Mac Digest V2 #18".

 

[JDW]

Here's a March 1986 Mousehole blurb about the MicahDrive, posted apparently by the author of the software drivers for it.

There is an utter dearth of info about the MicahDrive though, which indicates the company must have been very shortlived and not popular in the market enough for many articles on it to remain in existence. But perhaps if there is a way to contact this STEVE BRECHER (see Mousehole article), he could shed further light on the drive and compatibility with 64k ROMs.

 

[Charlieman]

The bloke who posts as Steve Brecher in the poker forums is the same Steve brecher who wrote Mac software in the 1980s:

http://pokerforums.fulltiltpoker.com/online-poker-play7040.html&highlight=