TI had already lost money from the start, when the 9985 failed to be produced so they were required to use the 9900 with static ram to replace the 9985's on-board 256 byte cache. Then they had to add a 16 to 8 bit multiplexer.The TI 99 used the 9900 from the 70's. And the 9900 was designed to use either 8 or 16 bit memory.The TI had a 16-bit databus, it was _not_ designed for 8-bit memories without a multiplexer circuit.
Perhaps you're right.However, I've seen TI 9900 and 99/4a sites that said the 99/4a had an 8 bit memory bus.
Further I suggest you read the 990 Computer Family Systems Handbook By Texas Instruments published in 1975.
The manual covers the models of the 990 family, the 990/10, using a TTL implimentation, which could have through "memory mapping" up to 1 million 16 bits words; the 990/4 which used the 9900 chip.
"990 instructions build a 16-bit address word which may be views as describing a 64K X 8 CPU address space. The LSB is used inside the CPU to address bytes...." pg 2-8
"16 bit machines with bit, byte, and word capabilites" pg 2-1 This seems to suggest that 8 bit operations and addressing is possible. Roy -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =-----