There was, as you point out, the Famicom, which was designed to take upgrades, and a couple of upgrades were released in Japan for it. However, as you rightly point out, the NES version had an expansion port that was never used. The existence of that expansion port still means the console was originally designed with mid cycle upgrades in mind, like the disk drive the Famicom eventually got. There was also a Sharp version built in Japan called the Twin Famicom, which combined both the Famicom and Disk system in one, and this was designed with three expansion ports that never ended up being used AFAIK. Again, designed with updates in mind.
On to Sega, first with the Sega SG-1000, which after just one year was dropped and the redesigned SG-1000II replaced it. Although there's only tiny differences between these two, Sega also released the SC-3000, which was based on the 1000, but had a whopping 0.5Mhz stronger CPU
(the 1000 had a 3.5Mhz CPU, so half a Mhz was actually quite the upgrade). These were failures compared to the Famicom, which is why Sega kept re-designing and updating them (eventually leading to the Master System). This leads us to the Asia-only Sega Mark III, which was, again based on the 1000 series. This had 3 add-ons designed for it, and was redesigned as the Sega Master System, and sold world-wide. The Master System was relatively successful, despite being the fifth update of the Sega systems it was based on. To put this into perspective, the first SG-1000 was released in 1983, and the Master System was released in 1986. That's five systems in three years!
Then Sega brought out the Genesis, or Mega Drive, which was designed with a number of updates in mind, . These included the Mega CD, of which there were a couple of versions, the 32X which expanded the Mega Drive to full 3d 32bit capability with two 32bit processors and a 3d capable GPU. The 32X was an enormous failure thanks to Sega releasing an independent 32bit console (Saturn) at the same time. There was also a Karaoke thing and even a wireless controller released for the Genesis/Mega Drive, but with all of these plugged into the system, it looks like an absolute mess (I have a friend with all of these things, the system is massive with all of them plugged in).
Then we have the Super Famicom and SNES. These were designed with an expansion port too, which as we know was for the fabled SNES CD that Sony was working on for Nintendo, that thanks to their falling out, never came to be, and actually led to the first Playstation. That's another system designed for mid cycle updates.
Next is N64, which had two expansion slots, one for the Expansion Pak, which doubled the system RAM, and another for the 64DD, which never made it outside of Japan. Nintendo sure loved selling us systems that were designed with mid cycle updates in mind didn't they?
Next, and this is a unique one, was the fat PS2. It had an "expansion bay" which was for upgrading the system to allow for a 40gb hdd for game installs and an network adaptor for online gaming. Both of these upgrades were released, but you had to buy the hdd pre formatted off Sony, as it needed their software to work properly. The hdd also didn't work without the network adaptor, so you needed both. Sony also brought out the Linux kit for the PS2, which used an ethernet only network adaptor (there was an earlier network adaptor sold in the USA with a dial-up modem and ethernet jack), plus the hdd, and also came with a VGA adaptor, and keyboard and mouse, so the PS2 could be used as a Linux PC (must have been the worst PC ever
). The later slim PS2 models got rid of this upgrade capability. This was, AFAIK, the only Sony console released with upgrades in mind to date.
Lastly, and I've no doubt missed some along the way, but Nintendo also released the Gamecube with expansion ports. One was never used in the end, another I think was for playing gameboy games, and the last was for upgrading to a LAN adaptor or modem.
I know you said "name one", but considering you then went on to name two yourself, I felt the need to name the ones I know of, which, as I said in my original post, is "many". Mostly these are earlier consoles, and I don't think any Gen 7 or 8 consoles were made to be updated, however, it seems Sony is now changing that with the PS4. I still don't think this is going to affect current PS4 owners, beyond any butthurt some may feel about not having the best console anymore, but considering current consoles are so weak compared to PCs anyway, I don't know why anyone would really care. Games aren't going to suddenly run like **** on PS4, nor will they stop being made, because Sony would know either of those scenarios would severely damage them this gen, whilst they are dominating in sales. It's also not just Sony doing this. Microsoft first indicated they too were doing a kind of mid cycle update, but now are backpeddling (as they have with just about everything to do with XB1
) and saying vague things about not wanting bolt-on upgrades, or an "Xbox one and a half", but suggesting they will probably release their next console much earlier than usual.
Sorry about the massive post lol. I'll end with this: I understand that it bothers some people, but it doesn't bother me, for reasons I've gone into detail on, and the crying about it is already getting old, so I don't think I've got anything else to add to the thread.