View Full Version : Working on a couple of SMC-70s

January 1st, 2017, 11:39 AM
I've finally gotten around to working on the two Sony SMC-70s that arrived on my doorstep a few months ago.

Probing the mono composite out port on one machine, I found the video signal on the center pin of the 8 pin DIN socket. No idea what the other 7 pins are for, aside from maybe a speaker output.

Once I was able to connect a monitor, I found that the unit with a bad keyboard (a couple busted key switches) had good RAM, while the unit with a good keyboard gave a memory error on boot.

So, one keyboard swap later, I've got a working unit and a parts rig. Only, I have no documentation or software. The machine boots into a system monitor, and from some fiddling I've discovered that pressing the B key in the system monitor loads a Sony BASIC interpreter from ROM.

That's about as far as I've gotten with this box. I haven't found any manuals or software online, the closest I got was this site (http://web.archive.org/web/20110719205252/http://ahm.ath.cx/smc70/), but unfortunately the original site is down and the software wasn't archived.

So, if anyone has a manual they wouldn't mind scanning, or software they wouldn't mind imaging, I would really appreciate it. I hope to be able to get this system up and running with CP/M, preferably in color if I can find the pinout of the DB25 RGB connector.

And for anyone interested, here are a couple pics of the current setup:

January 1st, 2017, 12:47 PM
Dave Dunfield has archived an SMC70 boot disk here (http://www.classiccmp.org/dunfield/img54306/system.htm)

The SMC-70 is kind of special in the firmament of CP/M machines. Not only was it the first to use 3.5" floppies OA-D32 drive manual here (https://www.manualslib.com/products/Sony-Oa-D32w-3614886.html), but it had a plethora of options, including ROMS for Kanji character support, Genlock option with video titling software, and even an add-on 8086 box that enabled it to run MS-DOS. It was expensive, alas--and a bit late to the PC scene. It was also only one of two CP/M systems to run VisiCalc.

You'll find the floppies quite a bit zippier to use than standard 5.25" fare because the drives in these boxes (as well as early HP boxes) spin at 600 RPM, not 300 RPM. I was involved in a US outfit to equip their portable CP/M box with the OA-D32 drives at around the same time--it was called the "Preis PC" and I even coded for the MFM HD controller. It was a contract job and I never knew what became of the company. I still have the BIOS source listing, however.

When the SMC-70 came out, there was a war of the "pocket floppy" formats. I still have the 3.25" Dysan floppies and drives. To the best of my knowledge, they only saw commercial use on the Seequa Chameleon 325--and most likely, any survivors have had the drives replaced with regular 3.5" DSDD ones. I think Shugart and Dysan were in the 3.25 camp, while Sony and HP were in the 3.5" one.

Congratulations on your acquisition.

January 2nd, 2017, 05:58 AM
Thanks for the links and the info. That CP/M boot disk was just what I was looking for.

I had read about the 600 RPM drives, they do make a pretty noticeable difference. I was a little surprised that the drives in my system are working well after all this time, albeit with some mechanical issues when loading or ejecting disks. A drop of lubricant and they're working like new.

I wasn't aware there was an 8086 add-on for this machine, sure would be nice to come across one of those some day. All in all this seems like a great little CP/M box, and I'm glad to add it to the collection.

And again, if anyone knows where I can find software or manuals for this system, it would be a big help.


January 18th, 2017, 07:22 PM
The default colors are white text on a dark green background.
Use SETUP to select something more legible on your display.
Try white text, black background and black border.


January 19th, 2017, 05:47 PM
Chuck, is new or NOS 3.5" media still available for this system anywhere?
I think it originally used Sony OM-D3320.

November 2nd, 2017, 02:02 PM
I probably have a collection of manuals and software, I'll check what I have and scan it in if you're still looking for it.