I have to assume that the TI Lisp chip was effectively just a CADR-on-a-chip (actually Lambda-on-a-chip) rather than a new architecture, necessary to support their software base.
The only mentions I have seen were of changes for TI Explorer from Lambda, so I could not figure if it involved any kind of different circuitry
The Lambda had memory management hardware that could make use of the extra virtual address space, the CADR didn't. Any of the machines could handle 24 or 25 bit integers.
programs.
] Pointer Fields Now 25 Bits; Flag Bit Gone.
Each typed data word in Lisp machine memory used to have one bit called the "flag bit" which was not considered part of the contents of the word. This is no longer so. There is no longer a flag bit; instead, the pointer field This extra bit extends the range of integers that can be represented without allocation of storage, and also extends the precision of small-floats by one bit.
On the Lambda processor, the maximum size of virtual memory is doubled. This is the primary reason for the change. Unfortunately, the CADR mapping hardware is not able to use the extra bit as an address bit, so the maximum virtual memory size on a CADR is unchanged.
The functions %24-BIT-PLUS, %24-BIT-DIFFERENCE and %24-BIT-TIMES still produce only 24 bits of result. If you wish to have a result the full size of the pointer field, however wide that is, you should use the functions %POINTER-DIFFERENCE and %POINTER-TIMES (the last is new), and %MAKE-POINTER-OFFSET with a first argument of DTP-FIX to do addition.
The functions %FLOAT-DOUBLE, %DIVIDE-DOUBLE, %REMAINDER-DOUBLE and %MULTIPLY-FRACTIONS use the full width of the pointer field.
The values returned by SXHASH have not changed! They are always positive