It's the hidden game inside Eric Boez's Muffie's Conversions cartridge (https://youtu.be/fvOev-hwp_U). AFAIK, it never came into public. But I bet some users might have it lying around and Muffie wouldn't really care if someone starts distributing it.
If I remember correctly, someone (from Italy) also released this collection in a disk version that was distributed in a magazine.
His conversions were great, but then, later on GDX made some awesome progress. Including Coleco's sound chip on a cart (Gyruss if I remember correctly) and... if I'm not mistaken he also took advantage of SCC and/or FMPAC in some of his conversions. Isn't that right GDX?
I just want to say that to convert Coleco ROMs, you have to adapt the interrupt routine and graphics routines on a case-by-case basis. There is little chance that it will work correctly by taking the routines of an already converted ROM as it is. The developer arguably gave up Mission for this reason.
I just want to say that to convert Coleco ROMs, you have to adapt the interrupt routine and graphics routines on a case-by-case basis. There is little chance that it will work correctly by taking the routines of an already converted ROM as it is. The developer arguably gave up Mission for this reason.
On Coleco, interruptions occur no matter what at 0066h. The only way to stop them is by disabling the VDP interrupt requests. (Some games do it)
The maskable interrupt routine at 00038h is called by some games with RST 38h.
We could have just reversed the addresses in many cases if the Z80 had an RST 66h but this is not the case.
Anyway, it's often difficult to ensure that interruptions don't happen at the wrong time. This occurs in Choplifter that you have converted, and it is not the only one. This is the most critical thing to convert Coleco games. It may take a while to fix that.
Coleco games were generally developed only for the PAL version or for the NTSC so the timings do not vary (always the same CPU, no wait and same interrupt). This is not the case on MSX. You have to take that into account.
