Had to make the following changes in order for your code to run under Pinnacle. I'm not quite sure what you are doing with SCON. Setting it to #7Ah gives you the following:
7A = 0111 1010

Bit 7&6
01 = Mode 1 8-bit UART Variable baud rate
bit 5
1 = Multiprocessor comm feature
bit 4
1 = Enable Reception
bit 3
1 = 9th transmit bit for Modes 2 & 3
bit 2
0 = RB8 = 0
bit 1
1 = Transmit Interrupt flag set
bit 0
0 = Receive interrupt flag not set

I moved CLR TI to the beginning of the Interrupt routine. Also relocated MOV A,#20h before the Interrupt enable instruction, otherwise the first interrupt prevents loading ACC with data. I think loading 00h to SBUF will not result in a transmit. If I am wrong I hope someone will clarify.

Your code which runs successfully on Pinnacle:

ORG 00h
LJMP MAIN
ORG 0023H
LJMP SPISR
ORG 0030H
MAIN: MOV SCON,#7AH
MOV IP,#038H
MOV TMOD,#20H ; TIMER 1 MODE2
MOV TH1,#0FDH ; 9600 BAUD RATE
SETB TR1
MOV A,#20H ;moved this line here
MOV IE,#90H
SJMP $
SPISR: CLR TI ;moved this line
PUSH PSW
CJNE A,#7FH,SKIP
MOV A,#20H
SKIP: MOV SBUF,A
INC A
POP PSW
RETI
END

Also, in a response to another earlier posting Erik stated in very strong terms that any unused interrupt vectors should have a RETI at that location. I heartily (and humbly) endorse his suggestion. I'm sure we all have horror stories of unexpected interrupts vectoring into the Enchanted Forest, never to return.

Hope this helps,

Hal