Every time I build an application for the TI-83 + calculator (Z80 processor), it stops working on CALL. Here is an example ("Hello") - it starts normally, but the calculator hangs in the CALL instruction. Everything that I put before CALL works fine, and everything that I put after does not start. This is code parsing to show addresses, not labels. I “touched it” to show the DB lines where they get to make it easier to read.
I have never had this problem writing prefabricated “programs” (which are loaded into RAM). The only problems I know with running "applications" (which are stored in Flash ROM) are that they cannot be self-modifying, and because of the need for swapping, access to data on a separate page is not possible. This is not self-modification and only one page ... What have I done wrong?
0080 218900 LD HL, 0089h
0083 cd9900 CALL 0099h ; --- App stops here
0086 c38f00 JP 008fh
0089 48656c6c6f00 DB "Hello", 0
008f fd360500 LD (IY+05h), 0
0093 ef RST 28h ; B_CALL (
0094 364c DB 4C36h ; _ReloadAppEntryVecs)
0096 ef RST 28h ; B_CALL (
0097 2740 DB 4027h ; _JForceCmdNoChar) --- App should end here
0099 7e LD A, (HL) ; --- Call goes to here
009a ef RST 28h ; B_CALL (
009b 0445 DB 4504h ; _PutC)
009d fe00 CP 0
009f c8 RET Z
00a0 23 INC HL
00a1 18f6 JR 0099h
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