68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.
New Macintosh Color Classic owner, questions about the MacEffects Thunder PDS 32Mhz Accelerator VS a LC 575 Board
Posted by: JohnnyPhantom on 2023-07-27 06:28:56
Hi Everyone,
I just got a Macintosh Color classic from a member on this site, I recapped the analog board (the logic board was already recapped) replaced the drive with a ZuluScsi drive, and maxed out the ram at a whopping 10MB! I also have a math coprocessor on the way. I have my eye out for a 256k NVRAM upgrade as well as a LC 575 logic board eventually to speed it up. I just came across the MacEffects Thunder PDS 32Mhz accelerator. Would this be as good as the LC 575 upgrade for my CC? Trying to decide between the two upgrade routes. Typically I'll find a YouTube video or some post for questions like this, but I'm unable to find anything really. So I just don't know. Can someone tell me the pros and cons of either?

Thanks everyone!!
~John
Posted by: Phipli on 2023-07-27 06:38:38
Hi Everyone,
I just got a Macintosh Color classic from a member on this site, I recapped the analog board (the logic board was already recapped) replaced the drive with a ZuluScsi drive, and maxed out the ram at a whopping 10MB! I also have a math coprocessor on the way. I have my eye out for a 256k NVRAM upgrade as well as a LC 575 logic board eventually to speed it up. I just came across the MacEffects Thunder PDS 32Mhz accelerator. Would this be as good as the LC 575 upgrade for my CC? Trying to decide between the two upgrade routes. Typically I'll find a YouTube video or some post for questions like this, but I'm unable to find anything really. So I just don't know. Can someone tell me the pros and cons of either?

Thanks everyone!!
~John
The truth is, the 575 board would be a much better upgrade. I'm not a ColorClassic person, so I don't know a huge amount of detail, but the 575 mostly fits and would give you a 33MHz 040, which would be about... well, 5 or 6 times faster? The ColorClassic only has a 16bit bus and is limited, like you said, to 10MB - the 575 can use more than 128MB of RAM. SCSI is faster, it can use 32bit expansion cards. I think you need a new rear logic board cover is the big issue because the ports move.

With the Thunder PDS, you're still limited by a 16MHz 16bit bus (vs the 33MHz, 32bit bus on the 575), so the card only runs at full speed when something is cached or doesn't need to access the logic board beyond the PDS expansion slot.

The downside is I believe the 575 boards are very hard to find. If you can get one at a price you're happy with, probably a great purchase.

Another option is the LC 550 board. Its slower, a 33MHz 030, but is a more direct fit and still gives you a 32bit, 33mhz bus.
Posted by: JohnnyPhantom on 2023-07-27 06:44:21
Awesome! Thank you too much for the info! Extremely helpful!
1