CV ROM Update Project - System Test WIP

[Ikrananka]

Inspired by my CV ROM Update Project - Commercial Releases, I have now decided to embark on trying to compile a complete set of working, clean, ColecoVision System Test ROMs along with documentation for their use.  I also plan on putting together a matrix showing what function each system test ROM performs.  So, for example, if you want to test the spinner on your Super Action Controller, or the VRAM on you ColecoVision, you'll know exactly which system test ROM to use and how to use it.  Much of my inspiration for this was frustration at not personally having a full working set and not knowing how to use them all and when to use them.  I was also further inspired by the superb work of NIAD on Sorting out the CV & ADAM Utilities. 

 

This project of mine is just a Work In Progress at the moment, and I may well need help to get to the first release, but I thought I'd get the ball rolling by discussing one particularly weird, non-functioning, system test ROM that has been in the public domain for at least two decades and is all over the internet on sites hosting ColecoVision ROMs, i.e. the so-called "CBS ColecoVision Monitor Test" also known as "ColecoVision Monitor Test".  As mentioned, this 16KB ROM does not function at all, so I decided to investigate.  The mystery thickened when I read NIADs comment that "This is a 16K file that I am not sure is an actual Coleco made program".

 

First, while I found that there are quite a number of different filenames for this ROM online, the actual ROMs are all identical.  Second, I have found absolutely no information about where this ROM originated from, what cartridge(?) it was supposedly dumped from, or what the program did (other than gamesdatabase.org which claims that it "was created in 1982 to test the monitor settings for the ColecoVision to Television interface." But then goes on to say that "This game was only a demo").  It's funny because the screenshots from gamesdatabase.org just show the "TURN GAME OFF..." BIOS screen.  In fact, I have found absolutely no working copy of this test program or a single screenshot demonstrating what it looks like.

 

Well, I've figured out why the 16KB ROM doesn't work.  To explain, let's break the ROM file down into two 8KB parts.  There is some indication online that the original dump (if there ever truly was one) was made up of two individual 8KB binary files.  See here and here where two 8KB ROMs named "cbsmon.1" and "cbsmon.2" are cited as making up the overall 16KB program.  Upon closer examination I soon found that the first 8KB of the 16KB ROM found online is made up of cbsmon.2 and the second 8KB part cbsmon.1.  However, cbsmon.2 is in fact identical to the standard NTSC ColecoVision 8KB BIOS - no wonder it doesn't run as a cartridge ROM file.  Digging further the second 8KB of the 16KB ROM (cbsmon.1) only contains 160 bytes of code/data with the rest being 0xFF.  Searching my large ROM collection, I can find no other ROM that contains this 160 bytes of code/data so this may in fact be a good dump of a second 8KB EPROM from the original test cartridge.  Unfortunately, without a good dump of the first 8KB this ROM file is currently useless.

 

Does anyone know any of the history regarding this ROM or the actual test program?  Does anyone here actually own this cart?

 

Also, does anyone know eBay member axtelius?  He purchased a ColecoVision Nuvatec test cartridge that way back in 2006 that appears to be quite unique and I have never seen a ROM file for it.