Recapped my MicroMac Accelerator card!

[corbinq27]

When I inherited my Grandmother's Macintosh SE, it came with a little surprise: a MicroMac Accelerator card. It goes on the PDS and bumps the machine to a 68030 @ 25 MHz with support for at least 16MB of RAM. Some of you may have seen it when I was at VCF Midwest 19 last month.

There's an issue I've had with the machine as of late: when I boot it I get an EYOERR on it. If I leave the machine plugged in for a few minutes it resolves itself. That seems like a capacitor problem and sure enough there was plenty of juicy oxidation and cap juice on the card.

I finished recapping it tonight. The good news is the card is working just fine. The bad news is it still does that EOYERR thing. I'm guessing I'll need to look at the analog board next but feel free to chime in with your opinions.

Also: I'm pretty sure that before I recapped it when I played the Oregon Trail 1.0 the game would freeze. I did not seem to run into this issue tonight.

I've installed the Connectix extension / control panel piece that lets the machine actually see the extra RAM. I was told by someone at VCF MW 19 that there's some fun stuff you can do with a RAM disk with this card too that I'll have to try sometime.

Here's some pics. Not my best solder work but alas.

Also: I have a hunch it's using the RAM on the main motherboard and not the RAM on the card. Perhaps the RAM on the card is only for the RAM disk. I'll have to confirm that at some point too.

 

[corbinq27]

And here's the webpage for that particular card. looks like 16MB of RAM is the limit and you can do a 4MB RAM disk: https://www.micromac.com/products/multispeed.html

 

[GreenBar0n]

That's too cool that the onboard 4Mb memory was repurposed for a RAMdisk, not much use for it otherwise. Nicely done!

 

[KennyPowers]

I was told by someone at VCF MW 19 that there's some fun stuff you can do with a RAM disk...

Also: I have a hunch it's using the RAM on the main motherboard and not the RAM on the card. Perhaps the RAM on the card is only for the RAM disk. I'll have to confirm that at some point too.

It looks like you installed 16MB (4x 4MB SIMMs) on the card after recapping, and "About this Mac" is showing 16MB of RAM. If so, and you have the "Application Memory" slider all the way up to 16MB in Compact Virtual (as I expect you do), then you're using the RAM on the card. You can confirm this by enabling the "Swap Indicator" option in Compact Virtual. When this is enabled, you'll see a small flashing pixel at the top left corner of the screen any time the hard drive is being used for application memory. I don't think you'll ever see this flashing pixel because you're using the 16MB of physical RAM installed on the card.

The 4MB of RAM installed on the SE's logic board can still be used as a RAM disk in this configuration, but it can't be "added" to the RAM installed on the card to have 20MB of addressable memory.

I recently uploaded the manual and quick reference guide for Compact Virtual to the garden:

https://macintoshgarden.org/sites/macintoshgarden.org/files/manuals/Connectix_Compact_Virtual_3.0_manual.pdf

https://macintoshgarden.org/sites/macintoshgarden.org/files/manuals/Connectix_Compact_Virtual_3.0_quick_reference.pdf

Page 3 of the manual describes how you can slice up the logic board and accelerator RAM into system memory and a RAM disk.

I also uploaded what appears to be a later ROM version for that accelerator:

https://macintoshgarden.org/apps/micromac-multispeed-accelerator-rom-dump-v31

I have no idea what it does beyond changing the animated startup screen to MicroMac branding (IIRC, your's boots up with NewLife branding as this accelerator is originally a NewLife design).

The bad news is it still does that EOYERR thing.

Do you have a picture of this?