1 8080 MACRO ASSEMBLER, VER 3.0 ERRORS = 0 + 07:34 07/16/2019 + PAGE 1 0000 ORG 0 ; ; SIO REV 1 LOADER FOR ALTAIR BASIC ; ; ** FOR VERSIONS < 4.0 SET SENSE SWITCHES A11, A10 ON ** ; ** FOR VERSIONS >= 4.0 SET SENSE SWITCHES OFF ** ; ; H = MSB OF LOAD ADDRESS ; L = LSB OF LOAD ADDRESS = LENGTH OF LOADER = LEADER BYTE ; LXI H,00F7DH ;4K BASIC V3.0 ; LXI H,00FAEH ;4K BASIC V3.2 ; LXI H,00FC2H ;4K BASIC V4.0 ; LXI H,01F7DH ;8K BASIC V3.0, V3.1 ; LXI H,01FAEH ;8K BASIC V3.2 ; LXI H,01FC2H ;8K BASIC V4.0 0000 21AE2F LXI H,02FAEH ;EXTENDED BASIC V3.2 ; LXI H,03FC2H ;EXTENDED BASIC V4.0, V4.1 ; LXI H,07EC2H ;EXTENDED DISK BASIC V5.0 0003 311200 LOOP: LXI SP,STACK ;INIT SP SO A RET JUMPS TO LOOP 0006 DB00 IN 00H ;GET SIO STATUS 0008 0F RRC ;NEW BYTE AVAILABLE? 0009 D8 RC ;NO (JUMPS BACK TO LOOP) 000A DB01 IN 01H ;GET THE BYTE 000C BD CMP L ;NEW BYTE = LEADER BYTE? 000D C8 RZ ;YES (JUMPS BACK TO LOOP) 000E 2D DCR L ;NOT LEADER, DECREMENT ADDRESS 000F 77 MOV M,A ;STORE THE BYTE (REVERSE ORDER) 0010 C0 RNZ ;LOOP UNTIL L = 0 0011 E9 PCHL ;JUMP TO CODE JUST DOWNLOADED 0012 0300 STACK: DW LOOP END NO PROGRAM ERRORS 1 8080 MACRO ASSEMBLER, VER 3.0 ERRORS = 0 + 07:34 07/16/2019 + PAGE 2 SYMBOL TABLE * 01 A 0007 B 0000 C 0001 D 0002 E 0003 H 0004 L 0005 LOOP 0003 M 0006 PSW 0006 SP 0006 STACK 0012