mbbrutman wrote:I'm just merely pointing out that the point of view of the people who designed the machine is quite different than your interpretation.
It isn't. This whole thing about 'design' is entirely your own fabrication, all part of your scheme to 'prove me wrong' in your giant ego-trip.
I merely said this: "Because of the memory accesses, the memory also gets refreshed automatically, but that is a side-effect rather than the reason."
Which I said to point out that the memory REALLY doesn't need to be refreshed every 4th cycle (refreshes are required every 72nd cycle if I'm not mistaken), and that there are other reasons why the CPU can't access the memory all the time, which were not mentioned previously.
Nothing about 'design features', since that is hardly relevant... unless of course you want to turn this thread into some kind of ridiculous PCjr-worship.
mbbrutman wrote: To them, the video controller refreshing the memory was a design feature, and they used it as such. You don't have to accept it, and clearly you don't.
Another fabrication of yours. I never denied any of it:
"So if you want to stick to your opinion that this was a design feature of the PCjr, even though the chip existed long before the PCjr did, and was used in many other machines before the PCjr was designed, that's up to you.
It is my opinion that this is a rather strange view of reality."
...
"I'm not. I'm saying that I think it's a silly view to have, I'm not denying that they may actually think this.
And I said why it's silly: video chips have been designed in a way that their access patterns refresh all video memory, without the need for any additional refreshing for years before the PCjr arrived. And home computers have been designed to share video memory with system memory, therefore not requiring additional refresh for years before the PCjr arrived.
So if those IBM engineers are like "Wow, look at this cool feature we've just designed!", using this off-the-shelf Motorola chip which tons of people have used in the exact same manner before them, then yes, I think they're being silly."
I think to me it is more or less analogous to referring to a phone's ability to make phone calls as a 'design feature'.
My ego is not the issue here.
Apparently it is. PC design seems to be a touchy subject for you.
Everyone with half a clue knows that pretty much every other system out there was more advanced/refined.
The PC is full of kludges and limitations, such as 16-bit segmented addressing, and DMA being limited to operating within single 64K pages.
Then there's tons of things it simply lacks altogether, such as hardware scrolling, sprites, raster interrupts, custom character sets etc.
And that's just looking at the features. If we also look about HOW they designed it... They needed full-size cards for MDA/CGA, filled with discrete 74xx logic and such, making them very expensive. Likewise, the entire motherboard of the 5150/5160 is filled with components.
Most other computers of the same era had considerably more elegant designs, integrating discrete logic into custom chips, making them a lot cheaper and smaller, while offering similar features or even more.
I guess you just need to get out more, broaden your horizon.
Those are pretty bold claims. I'm sure your designs have all been better.
That's not the point here, but thanks for proving my point about your ego-trip by supplying yet another fallacy in your line of reasoning.