Silly memory related question.

[am1933]

In various documents it states that the TI99/4a is supplied with 16K RAM-extendable to 52K, am I right in assuming that the 52k figure consists of 16K supplied RAM, 32K expansion and the 4K that is on-board the Mini Memory module?

[+Ksarul]

That would be correct from the standpoint of the hardware/software released by TI. It doesn't look at what shows up in all of the various ROM/GROM areas: up to 48K of GROm in the console/cartridge port area (and the O/S actually supports much more there, as the cartridge port actually supports 16 GROM bases, which would increase the total at the cartridge port from 30K to 480K). It is also possible to put GROM in the PEB, as was done with the p-Code card (48K of GROM). TI also built hardware that added more RAM than one would expect to the system. The TI 128K RAM card (this one was a TI prototype--I have one) put 32K where one would expect it to be, 8K in the cartridge RAM space, and an additional 8K in the DSR space--allowing for programs that used up to 48K of CPU RAM directly. The rest of the RAM was bank-switched in, so a program could have conceivably used all 128K of space on a regular TI. The speech synthesizer actually added another memory bus to the TI--you could have something like 588K of speech memory (the speech synthesizer adds 56K of that, IIRC), though most of it would have only been used by the never-released modules that would have added vocabulary (the connector for these carts survived under the door of some early speech synthesizers).

[davidgatx]

Thanks for the great question and detailed reply. This provides a lot of insight into some of the unrealized potential of TI-99/4A. If only TI had persevered, stayed in the home computer market, who knows what might have been.

[sometimes99er]

If only TI had persevered, stayed in the home computer market, who knows what might have been.

 

I would have liked that too.

 

TI-99/4A sold well in 1982 through to 1984. The cheaper the more and then TI abandons it.

 

Here's what I see as the bigger problems compared with other big players of that era.

 

The consumer will hear of or experience:

 

• Slow Basic (if not one of the slowest).
• Access to smooth (Basic compared with machine code) games only through cartridges (all others have native access to machine code).
• Inaccessible or at least relative expensive for future assembler programmers (Mini Memory or worse).
• TI obviously trying to keep in control (trying to lockout parties without license).

 

TI would face:

 

• More complicated architecture making it more expensive to produce.

 

The TI-99/8 does not seem to offer much more and would certainly not be cheaper to produce.

 

The Commodore 64 was there already (1982-), and Atari ST and Amiga was just around the corner (1985-). TI would have had to design something that offered more (than the TI-99/8) and relatively cheap. Making something not compatible with the TI-99/4A would unfortunately have been the only way to go. One option could have been to jump ship and make a slow shift (on the surface) making their version of the MSX standard, - perhaps promising a TI-99/4A add on to make people more happy to move and then probably not delivering on that one. TI could then have had a hand in shaping the future MSX2 (1986-). A good alternative to the C64, and (hopefully) a cheaper solution than Atari ST and Amiga.

 

Edited January 25, 2014 by sometimes99er