The expansion design was surprisingly advanced for 1982. Why didn’t Sony become a major PC manufacturer after this?
I remember reading about it in magazines when it launched but at ~$1500 for the base model at launch (without monitor) and still ~$1000 18 months later, for consumers it just couldn't compete with the $600-$800 Commodore 64 and Atari 800. In 1983 >$1,000 was a non-starter for amatuer hobby users, plus there weren't many game titles for it.
While CP/M was popular with the early IMSAI / SOL / S-100 homebrew hackers, it was never very relevant for most mass consumer hobbyists. CP/M was really disk-centric and in the early 80s floppy drives weren't within reach for the '2nd Wave' broader consumer hobby market. We got our first computers (C64, Atari 800, TI 99/4a, Radio Shack Coco) envisioning cartridge & cassette usage plugged into a TV we already had through an RF modulator. If you could afford it, the component RGB output of the Sony would certainly have looked incredible but in the early 80s most consumers were still a few years away from even seeing their first RGB monitor in person. No local store had ever even had one on display, so we didn't really know what to make of it. To us, Composite Video was the esoteric "better looking" output vs RF to your old TV. :-)
The SMC-70's price and capabilities were a better fit for business users but by '83, MS-DOS and "PC-Compatible" were clearly 'the future' for business users and CP/M was on the way out.
Consider that the C64 was also launched in 1982 for a much cheaper price and was available in non-NTSC regions too, so would have had a bigger software library available to it.
Many people can put up with less convenience with peripherals if you're paying an order of magnitude less up front.
Even the software on cassette and 5.25" disk would have been so much cheaper to distribute than the newly launched 3.5" disks (which were much better).
The SMC-70 could run CP/M software. CP/M was the MS-DOS of its time.
The MS-DOS world solved the problem by everyone just cloning the IBM hardware down to the disk format.
Unless the disks had copy protection, you could copy them over a serial link. I did that a lot between my Apple II and other CP/M machines.
FTL Modula-2 for example, had several low level portability modules depending on which CP/M machine you were actually using.
Since the PC used off-the-shelf components, it was tempting to be compatible, but some cursed machines tried to be different.
I’m not sure how compatible are floppies from the Victor 9000 or Epson QX-10, but I know the Sanyo 550 (?) and the Mindset, which were not quite PC-compatibles could interchange media with a PC.
CP/M programs written for other machines couldn't really make use of any of that unless they were rewritten specifically for the SMC-70.
If you just wanted the CP/M text compatibility and not the extended features you could buy a machine capable of that for much, much less.
As Kalleboo points out, if you wanted to buy off the shelf CP/M software you'd probably have to buy an external 5 1/4" disk drive too.
A lot of CP/M machines had graphics-capable built-in displays. Unfortunately, publishing software in machine-native media was a real chore back then, a bit like in the 1990's, where we had a "Unix version of NetScape" which was actually 27 slightly different versions for 27 different operating systems and binary architectures.
There was an HN post recently about the USA and Microsoft intervening to prevent Japan from getting too far ahead in PCs, combined with some of Japan's own mistakes.
I often joked, back then, that MSX was a brilliant effort to persuade Japanese computer manufacturers to invest in a family of nearly identical 8-bit systems so that they could compete in price rather than features.
I think it talked more about MSX. By the time it came to the states it was already competing with other better established things like Commodore. And then once the IBM PC became the big thing they really didn’t have anything special to offer. It was just another set of machines that, well built well, weren’t really any different.
Racism and protectionism probably played into it some, given the time period. But mostly their offerings weren’t as unique here. So many computers weren’t practical in Asia since they didn’t support any of the local character sets so at home they weren’t competing that much with those.
So in the end none of the brands really succeeded. They became a huge place to manufacture PCs for a long time, but it was almost always under someone else’s name.