GEOS enhancement ideas

[ytmytm]

• startup code that detects IEC/TCBM devices, RAM expansion; (with IOLib); setup status bytes (just like GEOS 64 does)
• bring back REU routines if there is RAM expansion (geoRAM style)
• use disk driver jump table as trampoline into ROM, into proper disk driver code (D64/81/82 from TCBM2SD, original TCBM, RAM drive)
• RAM drive can use GEOS 64 code for D64/81, through emulated REU calls
• use C2 cartridge for 32K of additional ROM code, startup must check for its presence and version/release byte