8085 Dissasembly?

[W2HX]

Hi Glen, Allison, Jonathan, Chuck, et. al.

Thanks everyone for the suggestions. I investigated the IDA Pro and unfortunately, the freeware version does not support 8085 and their lowest tier version costs $700 (ouch), but I will look into others like DASMx.  In case anyone is interested in the project, this is a transmitter system. There is one button called PWR when pressed it cycles through different output power levels - 125W, 500W, 1KW and then back to 125W and so on. Problem is, I have a 500W amp, not a 1KW amp. The manufacturer was kind enough to explain that they never got around to updating the firmware in the remote control for the 500W system and therefore it assumes 1KW is available. In my case when 1KW comes around the system goes into "funk mode".  All I am looking to do is to remove the 1KW option and have it cycle from 125W, 500W and back to 125W. I am hoping this could be done with a JMP in the right place or some NOOPs or something.

Appreciate the responses.
Eugene W2HX

-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Glen Slick via cctalk
Sent: Monday, April 16, 2018 8:35 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: 8085 Dissasembly?

You could post the EPROM files you have online somewhere for other people to take a quick look. Maybe create a thread on the vcfed forum and add them as an attachment to a message there. If you zip them up they should be small enough for an attachment.

I have only tried using IDA Pro a couple of times. I haven't learned how to use it well enough to be what I have used for similar 8-bit CPU disassembly tasks in the past. I have just written my own basic functionality 8085 / Z80 / 8051 disassemblers when I have had the need. Not too hard to make it smart enough to be able to specify known entry points (for example reset and interrupt vectors) and have it do reachable code traversal from there. Some things require manual intervention and iterative refinement, for example any indirect jumps through call tables, or calculated jumps. Using a professional tool might be quicker, but you might learn a lot more along the way doing things yourself.