From the 1979 catalog (the first one featuring home computers - the TRS-80), page 82: Editor/Assembler Program Although 16K of RAM is required, this package w

From the 1979 catalog (the first one featuring home computers - the TRS-80), page 82: Editor/Assembler Program Although 16K of RAM is required, this package will run with Level-1 BASIC. It is a 2-cassette program which creates both source and object files. Microsoft, an industry leader in systems software, has developed this program - so you can expect the ultimate in editing features. Standard Zilog mnemonics are used; macros and conditional assembly are not supported. $29.95