Just a heads up, check the card before committing to anything.You can also get a SB Pro / 16 and hook up a CD-ROM drive to that. I am considering that for my Magnavox 286.
True, but I think the OP was hinting at an EXTERNAL CD-ROM, which PCMCIA or SCSI would be ideal for.
Panasonic external CD-ROM drive with the provided PCMCIA card
My understanding is that those Cyrix clip on CPUs (or any other type of clip on upgrade for that matter) only work with 386SX "C Step" or later. Usually the "C Step" is lasered into the top of the CPU, but I'm not sure if this is always the case. The C step versions apparently had an extra pin that would disable the CPU when triggered.
Assuming such an upgrade worked in your system, the extra 1kb cache would give maybe a 40% improvement in raw CPU power. The clock doubling actually didn't seem to help much, at least in the systems I've tried them in. There are other clip-on adapters out there as well that use IBM SLC cpus with 16kb cache. Apparently those are quite fast, but hard as hell to find (I've never found one, and I look hard). Once again those would require a C Step CPU. So it's likely you would infact have to do some soldering.
Looks like your system can take proprietary CPU cards as well. That would be an option if you could find one. I wouldn't hold my breath on that one though.
Your system also uses a yucky Seagate ST 157 hard disk. Those used a short lived 8-bit version of IDE that isn't compatible with standard IDE drives. Probably if you want to upgrade that drive you'll have to disable the onboard controller and put a standard 16-bit one into one of your spare slots. Not sure if the XTIDE BIOS is helpful for this or not.
I had one at one point, but it didnt end up working for my application, so I resold to another member here about a year ago.
Here are some photos of the one I had:
View attachment 18958View attachment 18959
EDIT: they were clock speed specific, the one I had upgraded a 386-25 to a 486-50, the machine I wanted to upgrade was 20mhz, and no provisions for changing bus clock, so I never got it working. For this Magnavox you would need a 16/33 model to upgrade the 16mhz 386 to a 33mhz 486slc.
Let me guess, KXL-D745? Those are SCSI (and so are KXL-D740, KXL-D783). I have 2 of those still working, complete with SCSI/sound adapter PCMCIA cards. Been using one of them in my Thinkpad 755cx. I have also used one of them with an internal ISA SCSI card in a 486 machine a number of years ago. If you want to go that route, I recommend an Adaptec AHA 1542 card - you can still find them around fairly cheaply. You will also need a cable between the 50-pin high density connector of the CD drive to the Centronics 50-pin on the card. It shouldn't be too hard to find an appropriate cable online.
(edit) The connector on the drive is #4 below, the connector on the card is #1 below.