We have a copy of the following documentation from TI: "TI 99/7 COMPUTER HARDWARE THEORY OF OPERATION, Corporate Engineering Center, Dallas, By Richard Tarrant", dated 13 July 81. Based on this document, it appears the 99/7 was going to be based on the 9900 CPU, fully software compatible with the 99/4 (without the A), and include ALL OF THE FOLLOWING WITHIN THE SAME CASE (not as separate peripherals)- 64K of short wait state memory, speech, a "pascal grom", an 80 column thermal printer, an acoustic modem, and a 5.25 inch disk drive controller.

The following is quoted from this document: "The TI 99/7 computer incorporates the 99/4 home computer mainframe architecture with the 99/4 peripheral controllers plus expanded memory into the case plastics of the Digital Systems 765 terminal for compactness and portability. The TI 99/7 will retain software compatibility with the 99/4 while providing additional faster access memory as well as a larger keyboard and 80 column printer

"A comparison of features between a 99/4 with its external peripherals and the 99/7 is as follows:

[(memory in bytes/microseconds access per (word) or (byte)]

99/4 (** means external peripheral required)

• Operating system ROM...8k/0.7(W)
• Workspace RAM..........256/0.7(W)
• Display (VDP) RAM......16K/8.0(B)
• Internal GROM..........18K/6.0(B)
• Sound..................TMS9919
• Keyboard...............40 key polled
• Video Display..........40 char x 24 line color NTSC
• Cassette Interface.....1 port 650 baud 2 unidirect.
• Joystick Interface.....Dual scan/1 port
• External I/O...........40 pin full cpu with 8 bit data
• Expansion CPU RAM......32K/2.0(W)**
• Speech.................TMS0285+ 2-TMS0350**
• Printer................32 col/30 cps**
• Disk Controller........3-single density single side**
• RS232..................Dual 9600 baud**
• Modem..................300 baud acoustic originate**

TI-99/7

• Operating system ROM...8k/0.7(W)
• Workspace RAM..........512/0.7(W) Display (VDP)
• RAM......16K/8.0(B) Internal
• GROM..........90K/6.0(B)
• Sound..................TMS9919
• Keyboard...............58 key + 4 rock switch, poll or interrupt.
• Video Display..........40 char x 24 line color NTSC
• Cassette Interface.....1 port 650 baud 2 bidirect.
• Joystick Interface.....Dual scan/1 port
• External I/O...........9 pin with 8 bit latched data
• Expansion CPU RAM......64K/0.7(W)
• Speech.................TMS0285+ 2-TMS0350
• Printer................80 col/30 cps
• Disk Controller........3-single density double side
• RS232..................Dual 9600 baud
• Modem..................300 baud acoustic originate/answer