Sellam Ismail wrote:
> On Sun, 14 Apr 2002, James B. DiGriz wrote:
>
>
>>>Being this was made in 1981 (according to the page), and based on the way
>>>TI did things, I would not be surprised if there was a TI-99/4a at the
>>>core of this machine, with the carthridge slot used to throw different
>>>applications onto the machine for various data communications scenarios.
>>
>>I'm guessing this was a way to sell /4 mainboards still in inventory
>>after the /4A was introduced, among other things. The mainboard might
>>have been redesigned specifically for the Insight, though, which is one
>>of the things I'd like to find out.
>
>
>>From my understanding, the TI-99/4 and 99/4a are the same save for the
> keyboard.
>
> Are there any motherboard differences? I wouldn't think so.
>
> Sellam Ismail Vintage Computer Festival
> ------------------------------------------------------------------------------
> International Man of Intrigue and Danger http://www.vintage.org
>
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>
>
Different VDP's, as Frank mentioned, and different ROMs. The 4A adds
lower case ASCII characters, etc., The /4 has an equation calculator
mode missing from the /4A. There are other minor differences that mean
some /4A cartridges and disk software don't work on a /4.
Don't recall if it's the same PWB. I have one of each machine apart
somewhere around here and can look if you're interested. You're right,
though, there is no substantial difference between them. It's entirely
possible there's a /4A board in the Insight, just more likely a /4, in
my view. If it isn't something else entirely. It's possible if not
likely the terminal has its own ROMs, regardless.
By the way, I'm hearing of yet another prototype machine that has an
80-col display.
jbdigriz
Received on Mon Apr 15 2002 - 08:21:08 BST