41CL function request - is this possible? If so, how?

[Ángel Martin]

yes it's possible, even relatively simple:

1. YFNP setup. Using PLUGG? in the PowerCL to retrieve the ROM id# (or location address if it's in sRAM) to ALPHA. This you'd need to save it for later (the final re-plug step). It requires that you know if the currently plugged module is 4k or 8k though, as PLUGG? works at the page level. If the initial module was in RAM the last plug step needs to use the retrieved address and the "-RAM" token in alpha as syntax. For that final step it's probably better to use PLUGG (in the PowerCL) with the page# as parameter, instead of the port-dependent PLUG1/2/3/4/U/L functions.

2. YFNX setup. Using PLUG with the string "?xxx - pg#" retrieves the ROM id# plugged to the port (even if it's an 8k and that's the upper page). Much easier this way, as it works on the mnemonic rather than the location addresses.

Depending on how general-purpose you want this to be the logic would need to deal with the few scenarios - like 4k, 12k, or even bigger for both the current ROM and the one you want to use only temporarily. Like-to-like's would be easy, but if the "guest" module has a bigger footprint it may displace some others in the original configuration...

Another approach is using the alternate MMU configurations - you have three setups or "personalities", with functions STOCFG, RCLCFG and EXCFG to control the active one.