TI-99/4A Floppies

Allison ajp166 at bellatlantic.net
Tue Oct 2 20:43:42 CDT 2007

>Subject: Re: TI-99/4A Floppies
>   From: woodelf <bfranchuk at jetnet.ab.ca>
>   Date: Tue, 02 Oct 2007 17:52:04 -0600
>     To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>Brent Hilpert wrote:
>> I guess home computing got tossed over to the consumer products division at
>> TI, which always seemed to have a bottom-of-the-line/low-end approach to
>> things, too bad they didn't find some middle ground between that and their
>> higher-end commercial/military stuff.
>Well the hand writing was on the wall after 1975 since in hindsight
>we know that 16 bit computers with 32kw is just too small for any programs
>after about 1975. Look how hard it was to cram advent on a 32K pdp8.

That doesn't apply to the TI9900. the reason is the PDP-8 is a 4k machine
with a minimal instruction set and memory extension.  The 990/9900
is a 32KW CISC machine that can support memory extension into the 
megabyte range.  You forget the PDP11 was a 16bit 32kW machine too 
and that was highly successful.  Advent fit on Z80 with 48Kb and PDP11 
(LSI-11/03)with 28K of ram.

The reason the TI990/9900 was not wide spread is TI was not a computer company
and despite having something decent they didn't market it until it was way 
too late. In 1976-77 the 9900 was about one generation ahead of the 8080
and maybe Z80.  Maybe the best code example is the line by line assembler 
along with a simple monitor all in 1K words.  It was capable of very dense 

Actually the 64kB limit was not starting to be problematic until around 
1978-9{or later} when applications like DBASE and VISICalc started filling 


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