Machine Language Manager, by Bit Fiddler's, is a full machine language monitor for the Bally/Astrocade system that was released in 1982. It is a 2K cartridge intended for use by machine language programmers that have probably already dabbled a little bit with coding in ML using the Bally BASIC cartridge. Z80 Machine Code code is entered via hexadecimal using a special keypad overlay. The monitor doesn't have the functions of more advanced monitors on other computers from the same period. In fact, it has some strange idiosyncrasies (for instance, there is no backspace key), but compared to programming in machine language via the AstroBASIC cartridge, the Machine Language Manager is a breeze to use.
If you're curious about Machine Language Manager, I've provided several links here.
I quite like the cartridge label for this program. The picture online at BallyAlley.com is of high quality, but it doesn't do the silver, shiny, label any justice. Still it can be viewed here:
There is a keypad overlay (300 dpi version) for this cartridge, here:
The full, approximately 50-page, manual for the program is here:
Between March 2002 and January 2004 I typed-in the source-code for "Machine Language Manager" which was actually included with the cartridge when you bought it!). This version of code, a bit different from the included version, matches byte-for-byte with the 2K binary. The code can be downloaded here (it is ready to assembly with Zmac):