I was wondering what ever happened to Jim Butterfield, who was sort of a guru in the Commodore world back in the '80s. I found that he passed away just over two months ago, figured I'd pass the news along for those of you that remember him.

I remember one of my big projects back then was modding the C64 operating system ROM. I decided I wanted to include a machine language monitor in the ROM, so I looked around for one that would fit in the limited space I had available and remembered Jim's Tinymon for the VIC20, which was under 800 bytes. A few minor modifications to make it run on the 64 (and I added an ASCII display next to the hex readout) and I was in business. Very grateful to Jim for that one.

Is the source available for others?
TIA!

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That's too bad. He was a very gifted writer who had an incredible
knack for explaining how computers worked in everyday terms.
I will always be gratefull for his Book " Machine language for
beginners " ( or something like that )




Yes, He sent me a copy of "SuperMon" one time after I called him.
SuperMon was probably a later outgrowth of "TinyMon" and came with the
Book I referred to. Like alot of that stuff of the time ( 1985 ) you had
to enter the program using BASIC statements. Painfull..but fun

I think I have SuperMon in MS-DOS text format somewhere..I will take
a look.

Rest in Peace Jim & God Bless

Hmm.. I think that was around 20 years ago.. It will take me a while to find it if I even still have it.

Looks like there's a copy of tinymon here:

http://www.zimmers.net/anonftp/pub/cbm/vic20/utilities/unexpanded/

it's in .prg format, not sure if that's useful to you...

If you can get the VIC version it shouldn't be too hard to modify for the 64, a couple of the Kernal call locations need to be changed, and you have to change the number of memory locations it shows per line, that was pretty easy to change if I recall correctly.

I don't (of course) have the source for Blackadder's C64 version, but I have just finished an annotated disassembly of Jim Butterfield's original VIC-20 version, which you can find here. This covers both the monitor itself (monitor.a65) and the relocator that loads it into high memory (relocate.a65). The monitor will build to any location you like, but the current build system cannot build a relocatable version of the monitor.

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Curt J. Sampson - github.com/0cjs