First thing I'd do if it has the original factory install of Windows is image the hard disk. I still to this day regret not doing that for a DECpc LPv+ 466d2 around 15 years ago - I just casually blew away the factory windows install (with default DEC wallpaper, OEM programs for creating disks, etc) one day in an unsuccessful attempt to use the machine as a linux firewall. I could have just put a different hard drive in. Or imaged the existing one. But no, I wiped it.

As for upgrades - I'd put a network card in it if you've got a free slot after adding other more important things (sound card). Getting stuff on and off vintage computers using the LAN is a whole lot easier than floppy disks and serial cables.

I assume the machine takes 72 pin fast page memory modules (hard to tell from the picture). I don't know what the upper limit is but my box of FPM mostly seems to be 4 and 8MB SIMMs so I assume they're pretty easy to come by.

davidrg wrote on 2022-04-16, 23:24:

I assume the machine takes 72 pin fast page memory modules (hard to tell from the picture). I don't know what the upper limit is but my box of FPM mostly seems to be 4 and 8MB SIMMs so I assume they're pretty easy to come by.

Yep, if it were 30 pin SIMMs, there would not be a single one of them empty, but four at a time.

RAM, Populate both sockets with 8 MB modules. A 486 should have 16 MB of RAM.

That socket, afaik, if it were populated OEM, the solder spot would be empty. So, put a DX2-66 in, see what happens - probably will have to engage some jumper to have it know - never hurts to have a proper manual for those things.

Graphics, it seems that you could upgrade the onboard with 512 more kilobytes. Will afford you higher Windows resolutions or color depths, not important for 1994 or earlier DOS games.
New card, only if possible to deactivate the onboard via jumper or bios. Onboard is a Cirrus Logic GD542x, I assume - you could do worse.

sound:
https://www.pc-schnulli.de/hardw/skisa/sktr/cx423x_w31x.rar

have fun!

That's a really dreamy PC. I love how curved and bubbly the monitor is.

I found the manual for the PCS44 on Archive.org: https://archive.org/details/cap36_201908/cap35/

JUMPER JP1 Not installed: i486 SX processor soldered. Default setting. Installed: i486 DX or i486 DX2 coprocessor soldered (not […]
Show full quote

JUMPER JP1
Not installed: i486 SX processor soldered. Default setting.
Installed: i486 DX or i486 DX2 coprocessor soldered (not available on the M300-28/PCS44).

NOTE: If the i487SX or the Overdrive Coprocessor is installed in the coprocessor socket,
there is no need to set this jumper since the system will automatically detect that one of these coprocessors are present.

It sounds like this particular system doesn't come with a coprocessor but you could add one to the unpopulated socket, no jumpers needed. Maybe it also means you could install an OverDrive? There's an "ODP" variant that sits in its own socket and replaces an onboard/soldered CPU.

Each 486 Overdrive typically came in two versions, ODP and ODPR variants. The ODPR chips had 168 pins and functioned as complete swap-out replacements for existing chips, whereas the ODP chips had an extra 169th pin, and were used for inserting into a special 'Overdrive' (Socket 1) socket on some 486 boards, which would disable the existing CPU without needing to remove it (in case that the existing CPU is surface-mounted).

davidrg wrote on 2022-04-16, 23:24:

First thing I'd do if it has the original factory install of Windows is image the hard disk. I still to this day regret not doing that for a DECpc LPv+ 466d2 around 15 years ago - I just casually blew away the factory windows install (with default DEC wallpaper, OEM programs for creating disks, etc) one day in an unsuccessful attempt to use the machine as a linux firewall. I could have just put a different hard drive in. Or imaged the existing one. But no, I wiped it.

As for upgrades - I'd put a network card in it if you've got a free slot after adding other more important things (sound card). Getting stuff on and off vintage computers using the LAN is a whole lot easier than floppy disks and serial cables.

I assume the machine takes 72 pin fast page memory modules (hard to tell from the picture). I don't know what the upper limit is but my box of FPM mostly seems to be 4 and 8MB SIMMs so I assume they're pretty easy to come by.

Cuttoon wrote on 2022-04-17, 01:45:

Yep, if it were 30 pin SIMMs, there would not be a single one of them empty, but four at a time. […]
Show full quote

davidrg wrote on 2022-04-16, 23:24:

I assume the machine takes 72 pin fast page memory modules (hard to tell from the picture). I don't know what the upper limit is but my box of FPM mostly seems to be 4 and 8MB SIMMs so I assume they're pretty easy to come by.

Yep, if it were 30 pin SIMMs, there would not be a single one of them empty, but four at a time.

RAM, Populate both sockets with 8 MB modules. A 486 should have 16 MB of RAM.

That socket, afaik, if it were populated OEM, the solder spot would be empty. So, put a DX2-66 in, see what happens - probably will have to engage some jumper to have it know - never hurts to have a proper manual for those things.

Graphics, it seems that you could upgrade the onboard with 512 more kilobytes. Will afford you higher Windows resolutions or color depths, not important for 1994 or earlier DOS games.
New card, only if possible to deactivate the onboard via jumper or bios. Onboard is a Cirrus Logic GD542x, I assume - you could do worse.

sound:
https://www.pc-schnulli.de/hardw/skisa/sktr/cx423x_w31x.rar

have fun!

Cosmic wrote on 2022-04-17, 03:36:

That's a really dreamy PC. I love how curved and bubbly the monitor is. […]
Show full quote

That's a really dreamy PC. I love how curved and bubbly the monitor is.

I found the manual for the PCS44 on Archive.org: https://archive.org/details/cap36_201908/cap35/

JUMPER JP1 Not installed: i486 SX processor soldered. Default setting. Installed: i486 DX or i486 DX2 coprocessor soldered (not […]
Show full quote

JUMPER JP1
Not installed: i486 SX processor soldered. Default setting.
Installed: i486 DX or i486 DX2 coprocessor soldered (not available on the M300-28/PCS44).

NOTE: If the i487SX or the Overdrive Coprocessor is installed in the coprocessor socket,
there is no need to set this jumper since the system will automatically detect that one of these coprocessors are present.

It sounds like this particular system doesn't come with a coprocessor but you could add one to the unpopulated socket, no jumpers needed. Maybe it also means you could install an OverDrive? There's an "ODP" variant that sits in its own socket and replaces an onboard/soldered CPU.

Each 486 Overdrive typically came in two versions, ODP and ODPR variants. The ODPR chips had 168 pins and functioned as complete swap-out replacements for existing chips, whereas the ODP chips had an extra 169th pin, and were used for inserting into a special 'Overdrive' (Socket 1) socket on some 486 boards, which would disable the existing CPU without needing to remove it (in case that the existing CPU is surface-mounted).

Thanks for the replies, they've been very helpful!

I've decided against a separate video card for now, and will look into a network card of some sort instead. As you say this can be a good way for transferring data, which also saves me from struggling with various storage options. Good advice on imaging the original Windows installation too, I'll do this as soon as possible.

Since the PC only has one RAM socket, i'll find an 8mb stick to put in for now to bring it closer to the recommended 16mb.

Interesting to hear that the empty socket is for a CPU, I'll try a DX2 for now and maybe even an overdrive at some point!

And thanks for the links to the sound drivers and manuals, they'll come in very handy. Hopefully I'll get back at some point with some progress!

For imaging the hard disk, I've successfully used NCommanders DOS Disk Dumper recently though this is easiest to do if the machine is already on the network with a mapped network drive you can dump the image to. A boot disk with a network client on it is probably the easiest way to do that if you want to take an image before setting up any network stuff on the hard disk. Or if you've got a null modem cable there is one for dumping hard disks over serial but I'm not really sure how that one works.

davidrg wrote on 2022-04-18, 20:47:

Or if you've got a null modem cable there is one for dumping hard disks over serial but I'm not really sure how that one works.

slooooooooooooooooooowly!

There actually was a system to connect two PCs point to point via the parallel port, called "laplink". So far haven't tried it out but bound to be significantly less slow than serial...
Smaller harddrives you can dump on a parallel attached Zip drive, as well 😉