Make the TSTB size configurable

We would like to have the option to set the number of tape status table (TSTB) slots to a different value at SIP time. Failing that, we would like to see a larger hardcoded TSTB size.

The number of TSTB slots is defined in SIP macro sptabs.mac:
&SXCATAP SETA 63 TOTAL # OF TAPE DRIVES ALLOWED

This value is used in SIP macro sksycn.mac:
PUNCH 'CPMANT EQU &SXCATAP+1 # TAPE DRIVES ON SYSTEM'

Currently our z/TPF production system has 48 tape devices available on a local VTS and a further 48 tape devices on a remote VTS in our disaster recovery centre. These 96 devices are all connected to our Production CPU (and also to our fallback CPU). If our Production CPU could have these 96 tape devices defined in its TSTB then this would allow a smooth failover in case of problems on the local VTS. Unfortunately the TSTB capacity is 64 slots which is not enough for 96 tape devices.

We prefer to see the TSTB capacity made configurable, for instance by means of a new parameter on SIP macro config.mac with a default of 63 as per the current value in sptabs.mac.
Failing that, we would like to see the TSTB capacity increased so that we can use 96 tape devices.

In case this request is accepted I would like to point out that some IBM software do use a hardcoded value for the number of TSTB slots. This should be updated, I suggest using the conkc interface (label @02ANT). I did not perform an exhaustive scan.

Example 1: corm.c
for (tstbindex=0; /*PJ25098*/
( (tstbindex < 64) && (best_tape == 0) ); /*PJ25098*/
tstbindex++)

Example 2: bxdc.asm
BXTPSRCH DS 0H @410.049
SR R15,R15 GET TAPE SYMB MOD NUMBER @410.049
CINFC R,CMMTS1 GET TSTB SECTION 1 BASE ADDR IN R14
ITSTB SEC=1,REG=R14 @410.049
BXDC57A DS 0H @410.049
CLC CPMTNM,BXCUD2SX IS THIS THE TAPE NAME @410.049
BE BXDCSO YES, SO SEE IF IT IS A STANDBY
BXDC57B DS 0H @410.049
LA R15,1(,R15) INCREASE R15 @410.049
AL R14,=A(CPMT1S) POINT TO NEXT ENTRY @410.049
ST R14,EBX100 SAVE R14 @411.074
CL R15,=A(64) AT THE END OF THE TABLE @410.049
BNE BXDC57A NO CONTINUE SEARCH @410.049
DLAYC @410.049
B BXTPSRCH GO CONTINUE SEARCH @410.04