HP41CV with built-in Time Module

[brouhaha]

As others have noted, the electronics may not match the label.

If pressing [gold] CATALOG 4 shows the mainframe functions, just like CATALOG 3, then it really is a 41C or 41CV. If CATALOG 4 shows DIR EMPTY, or a listing of files in extended memory, then it's a 41CX.

Also, if CATALOG 2 includes "-TIME 2C", and includes "-CX TIME", "-EXT FCN 2D", and "-CX EXT FCN", then it's a 41CX.

If it's not a 41CX, but CATALOG 2 shows that it has another revision of the time module, then the time module has been installed internally. Sometimes such modification also include one or two Extended Memory modules, but usually not a Extended Function module, because that would conflict with an expansion port. With the ports empty, CATALOG 2 will tell you what other ROM modules may be installed, but it doesn't show extended memory modules.

If you can XEQ "EMDIR", that indicates that there IS an extended functions module installed (or in a port). if there's not one installed internally, plug one into a port and XEQ "EMDIR". It will probably say "DIR EMPTY", but when you hit the backarrow key, it will then show you how many registers of extended memory there are. If it's 124, that's just an extended function module, but if it's more, then there are one or two extended memory modules also.