On 12/13/2018 12:05 AM, Sean Conner via cctalk wrote: > It was thus said that the Great allison via cctalk once stated: >> On 12/12/2018 03:04 PM, Sean Conner via cctalk wrote: >>> It was thus said that the Great allison via cctalk once stated: >>>> The whole thing comes from a project for myself... >>>> I wanted a very basic screen based editor written in 8080/8085/z80 asm >>>> and compact >>>> (as in under 4K). I figured first lets inquire of the Internet to see >>>> if I need to and code exists... >>> I remember typing in TED.ASM from one of the PC magazines in the late >>> 80s. >>> Yes, it's for MS-DOS, but: >>> >>> 1) The 8086 is somewhat, kind of, source compatible with the >>> 8080/Z80 (if you squint hard enough) >> Your not serious? Z80 or 8080 to 8086 is not too bad but the other way >> is plain nuts. > I learned assembly on the 6809, then the 8086 (technically the 8088). I've > always heard that it was designed to make porting code from the 8080/Z80 > easy. But I never really learned the assembly for the 8080/Z80. I only > mentioned it because I think (if I recall) TED.COM was limited to editing > around 60K or so (one segment's worth of memory). The 6809 is one of the few I pay attention to as it was remarkably close to the PDP-11.
The 8088/86 is that it was designed as a 8085 with a bag on the side. The register correspondence from 8080/8085 to 8088 is good and lofting code usually works if you watch for odd errors like AH, is that the value A hex, or Accumulator high. Z80 however in base is 8080/8085 but had a second set of identical registers and 8088 has nothing like that. So unless one keep the Z80 code to the 8080 register model it does not translate well. In the reverse direction the 8088 has register (segment) and a few other that would have to be sorted out by hand. The size limit of 60K is not a problem as what I want is aimed at files in the 7-32K range. > But I can see it won't fit your needs. If it wasn't a handful to get ported to z80 it might have made a start. I found EDIT and EDITM both are based on EDIT CPMSIG vol 16 where edit M is more cleaned up and handles some things better. Both are very small under 2.8K. So that makes for a platform to add to by wiring in a set of recurrent edit macros that repeat and update the screen. Allison
