Performa 550 vs Macintosh TV

[l008com]

So a very long time ago, when I was a wee little 14 year old, I was getting my first "modern" computer. The choice ended up being between a Performa 550 or a Macintosh TV. BTW for those curious, this was up at the ComputerTown store in Salem New Hampshire.

Anyway, I was a young teen with his own room, I wanted the computer I could use as a TV and a computer, obviously. But I was talked out of it, and the primary argument I remember, was "if it breaks you have to fix a computer AND a TV". Which of course doesn't even make sense. The "TV" was just a TV tuner card and on the off chance that it did break, I'd just have no TV anymore. That was silly and I wish I had gotten that Mac TV!!

Also, I swear to god, I also saw a larger Mac TV at that apple store, but I've never seen any reference to it anywhere. It was black and had the "Macintosh TV" label on it, but it looked like it was a larger stand alone monitor for some other system. I swear I saw it, but I've never seen anything like that since. Anyone have any ideas about this? I guess someone could have just made a macintosh tv label and stuck it on a regular old black TV and used it as a monitor? But I don't remember it looking that way. I don't remember what was on it either. It was 30 years ago.

And my last comment on the topic, what was up with the RAM in the Mac TV? It was my every spec, just a Performa 550 painted black. Yet for some reason, the P550 could take a 32 MB chip in it's RAM slot, but the Mac TV could only take a 4 MB. That is the actual only reason not to buy the Mac TV, but that would have been moot anyway. After riding 5 MB of RAM for a long time, I eventually upgraded to 8 MB, but never more than that. That 3 MB upgrade cost $275, 12 MB was never going to happen, and 36 MB, LOL keep dreaming. But why did the Mac TV seem to have this artificial limit. I know it wouldn't be the first time Apple put a totally artificial, arbitrary limit on something, but in this specific case it seems really weird. Was there a resistor you could snip off the Mac TV board to allow it to see all 36 MB?

 

[adespoton]

I remember seeing a big black TV playing Macintosh TV demo videos back when that came out. The annoying thing in my case is that the store didn't have any actual Mac TVs available. Not that I could have afforded one at the time. I thought that the big black TV was the Macintosh TV and asked the salesperson about it and they said "oh, we don't have any; that's just a demo. Would you like us to order you one?"

 

[Fizzbinn]

And my last comment on the topic, what was up with the RAM in the Mac TV? It was my every spec, just a Performa 550 painted black. Yet for some reason, the P550 could take a 32 MB chip in it's RAM slot, but the Mac TV could only take a 4 MB. That is the actual only reason not to buy the Mac TV, but that would have been moot anyway. After riding 5 MB of RAM for a long time, I eventually upgraded to 8 MB, but never more than that. That 3 MB upgrade cost $275, 12 MB was never going to happen, and 36 MB, LOL keep dreaming. But why did the Mac TV seem to have this artificial limit. I know it wouldn't be the first time Apple put a totally artificial, arbitrary limit on something, but in this specific case it seems really weird. Was there a resistor you could snip off the Mac TV board to allow it to see all 36 MB?

The Macintosh TV might appear very similar in specs to the Performa 550 but it's my understanding that they have very different logic board architectures. The Macintosh TV having more in common with the LC II, Color Classic and/or Performa 600 (16 bit data bus with lower RAM ceiling, 16MHz IO bus but with processor clock doubled to 32Mhz) while the Performa 550 is closely related to the LC III+ (32 bit data bus, 33MHz IO bus and processor clock).

I think a similarly outfitted (RAM, HD) Performa 550 would benchmark higher (more than the 1MHz CPU difference) than a Macintosh TV due to its logic board improvements. (wonder if there are some benchmarks out there that can confirm this...

The rationale in my head is the teams working on the two machines had different goals, LC/Performa 520/550 were after general system performance improvement while the Macintosh TV team wanted an existing stable architecture to build their novel TV/Video features on top of.

The weirdest thing about this to me is the Macintosh TV did switch to using a 32 bit 72-PIN SIMM for memory expansion so maybe I have it wrong about the 16 bit data bus and being limited to a 1MB or 4MB SIMM was a specific/self limiting design decision. Apple worried about eating into Centris/Quadra AV model sales?

I looked for an Apple Hardware Developer Note for the Macintosh TV to confirm some of this but couldn't find one. Boo.

In any case I think the Macintosh TV is one of those super cool odd ball Macs, lots to like!

 

[Arbee]

Fizzbinn: you are correct. The biggest issue I had getting the Mac TV to boot in MAME initially was when I assumed it was LC III / 5x0 based. It's not. From software it looks almost exactly like an LC II or Color Classic. The memory controller is the only real difference from the V8 so it may well have a full 32-bit data bus. Speedometer would likely prove that either way.

It's one of two architectures that were part of the way between the LC II and LC III (the other architecture was the IIvx/IIvi, which is a bit closer to the III where the TV is closer to the II).

 

[croissantking]

Anyway, I was a young teen with his own room, I wanted the computer I could use as a TV and a computer, obviously. But I was talked out of it, and the primary argument I remember, was "if it breaks you have to fix a computer AND a TV". Which of course doesn't even make sense. The "TV" was just a TV tuner card and on the off chance that it did break, I'd just have no TV anymore. That was silly and I wish I had gotten that Mac TV!!

If the Mac broke then you’d have no TV either, whereas if you’d had a separate TV you could keep on using it. So the logic does make sense.