Hi Here is the code I have so far. I've shortened it a bunch but I don't think I can get it much shorter. I desided not to use any special Z80 instructions because I want this to work with the H8's as well ( these are 8080 box's but can run HDOS ). It is down to about 42 ( decimal ) bytes. If anyone can remove some more that would be great. I'm using the over writing of the jump address at the end of the code to stop loading and begin using the main down loader. This saved quite a bit of code but it means that I need to load the main loader backwards. This is a pain but not that big of a deal, compared to typing in a lot of bytes. For this code, if someone thinks of some other method that does something like self modifying code, I'm game to that. This is a boot strap and the key is being small. There are no other rules. I thought it would be a good idea to also have the ability in the main loader to save the main loader to disk as a bootable image. This would make it easier because one wouldn't need to keep typing in the first bootstrap loader every time one got more images to load, like a week later. Dwight BOOTSTRP.ASM ; 42 BYTE BOOTSTRAP LOADER WITH INIT FOR 8250 ; INTENDED FOR THE H89 BUT MAY ASLO WORK ON H8. ORG 2300H LDR: XRA A OUT LCNTL ; LINE CONTROL OUT IER ; NO INTERRUPTS OUT MCNTL ; INIT MODEM CONTROL DCR A ; SHOULD BE 'MVI A, 80H' BUT 0FFH OK? OUT LCNTL MVI A, 0CH ; 9600 BAUD OUT DVL XRA A OUT DVH MVI A, 07H ; 8 BIT 2 STOPS OUT LCNTL IN LSTAT IN RX ; CLEAR ANY JUNK LXI H, 2400H ; DEPENDS ON SIZE (TO BE DETERMINED) LDR1: IN LSTAT ANI 01 JZ LDR1 ; WAIT FOR CHAR IN RX MOV M,A DCX H JMP LDR ; ADDRESS TO BE OVER WRITTEN BY CODE LOADED