an ISIS-II-based translator from 8080 to 8086 source code named CONV86 (also referred to as CONV-86 and CONVERT 86) available to OEM customers since 1978, possibly the earliest program of this kind. It supported multiple levels of translation and ran at 2 MHz on an Intel Microprocessor Development System MDS-800 with 8-inch floppy drives. According to user reports, it did not work very reliably. SCP TRANS86 Seattle Computer Products' (SCP) offered TRANS86.COM, written by Tim Paterson in 1980 while developing 86-DOS. The utility could translate Intel 8080 and Zilog Z80 assembly source code (with Zilog/Mostek mnemonics) into source code for the Intel 8086 (in a format only compatible with SCP's cross-assembler ASM86 for CP/M-80), but supported only a subset of opcodes, registers and modes, and often still required significant manual correction and rework afterwards. Also, performing only a mere transliteration, the brute-force single-pass translator did not carry out any register and jump optimizations. It took about 24 KB of RAM. The SCP version 1 of TRANS86.COM ran on Z80-based systems. Once 86-DOS was running, Paterson, in a self-hosting-inspired approach, utilized TRANS86 to convert itself into a program running under 86-DOS. Numbered version 2, this was named TRANS.COM instead. Later in 1982, the translator was apparently also available from Microsoft. Sorcim TRANS86 Also named TRANS86, Sorcim offered an 8080 to 8086 translator as well since December 1980. Like SCP's program it was designed to port CP/M-80 application code (in ASM, MAC, RMAC or ACT80 assembly format) to MS-DOS (in a format compatible with ACT86). In ACT80 format it also supported a few Z80 mnemonics. The translation occurred on an instruction-by-instruction basis with some optimization applied to conditional jumps. The program ran under CP/M-80, MP/M-80 and Cromemco DOS with a minimum of 24 KB of RAM, and had no restrictions on the source file size. Digital Research XLT86 Much more sophisticated and the first to introduce optimizing compiler technologies into the source translation process was Digital Research's XLT86 1.0 in September 1981. XLT86 1.1 was available by April 1982. The program was written by Gary Kildall and translated source code for the Intel 8080 processor (in a format compatible with ASM, MAC or RMAC assemblers) into source code for the 8086 (compatible with ASM86). Using global data flow analysis on 8080 register usage, the five-phase multi-pass translator would also optimize the output for code size and take care of calling conventions (CP/M-80