The TI-99/4A’s CPU, motherboard, and ROM cartridge («Solid State Software») slot are built into the keyboard. For example, Alpiner’s speech includes male and female voices and can be quite sarcastic when the player made a bad move. This is expandable to 192kB with the use of a Yamaha V9938 as a user-designed modification (not a standard upgrade option). VDP RAM is also used for storing buffers for disk I/O, and variables and code for users’ BASIC programs. However, the success of software text-to-speech in the Terminal Emulator II cartridge cancelled that plan. In many games (mostly those produced by TI), the speech synthesizer has relatively realistic voices. Further upgrade chips, the 9938 and 9958, were produced by Yamaha based on TI’s design. Also, a number of emulators for the TI-99 exist today for PC-based systems.
Device drivers (called «Device Service Routines», or DSRs) are built into ROMs in the hardware; when a new card was inserted, it is immediately available for any software which needed or wanted to use it. These upgrades are not a simple drop-in and replace; a small board including the replacement VDP and replacement VDP RAM (usually 128kB) is required. In addition, although the chips were largely software-compatible, certain bugs in the ROMs cause compatibility issues with the new chips. Retrieved 5 February 2015. ^ a b c d e Mitchell, Peter W. (1983-09-06). «A summer-CES report». Boston Phoenix. p. 4. Retrieved 10 January 2015. ^ a b Green, Wayne (August 1980). «Publisher’s Remarks». Kilobaud. p. 8. Retrieved 23 June 2014. ^ «Commodore: New Products, New Philosophies». Kilobaud. Though it is prototypical to today’s USB (plug and play, hot-swappable, etc.), it was never released, with only a small number of prototypes appearing in collector hands after TI pulled out of the market. Sl CRS No Registration No Date of Grant Manufacturer IS No Product Brand/Models Status Valid Upto 1IR-410000192013-06-12Samsung Electronics Shandong Digital Printing Co. Ltd. The unusual architecture of the 99/4 series is documented to be due to the failure of the 9985, an 8-bit processor which was being created specifically for the machine.
The TI-99/4A enjoys an active after-life in the vintage computing enthusiasts world. Some sophisticated cartridges (for example Parsec, Alpiner, TI LOGO, TI Extended BASIC) include memory-addressable ROM which was available for machine code, primarily for games or applications which demand the speed of machine code. This also increases the VDP memory from 16K to a maximum of 192K, although only software explicitly written for the 9938 take advantage of it. Cost for attachment in this forum is 10 Points. The «sidecar» expansion units can be connected together in a continuing chain, but can rapidly occupy an entire desktop and cause crashes and lockups due to the large numbers of connectors on the system bus.