bridger%rcc@RAND.ORG (Bridger Mitchell) (12/01/89)
ZEX v 5.0 is a Z-System tool for obtaining console input from a script (or in-memory) file. The input can be provided to the command processor, an application program, or both. Version 5.0 requires an extended external environment descriptor in the ZCPR v.3.3 or v 3.4 system. That data structure includes the base addresses for the operating system segments -- BIOS, BDOS, CCP. If the address at (0001) does not correspond to the one in the descriptor, you'll get the message you reported: 'incompatible RSX changed address at (0001)'. The auto-install versions of ZCPR 3.4 (NZ-COM for cp/m 2.2 and Z3PLUS for CP/M 3.x) automatically provide the extended environment. A separate tool -- JetLDR -- is available for loading system segments in earlier systems; it upgrades the environment descriptor when a segment is loaded. In a correctly installed system, that message would normally result if some application, usually a mis-behaved RSX, had altered the contents of 0001. (An RSX should *always* leave 0001 unchanged. If it needs to intercept the warm-boot vector, it should modify the BIOS vector. Otherwise subsequent applications cannot locate the BIOS.) But in your case, perhaps the BIOS address didn't get set correctly when you modified the ENV descriptor? Further technical documentation on the Z-System can be found regularly in issues of The Computer Journal, 190 Sullivan Crossroad, Columbia Falls MT, 59912. -- bridger mitchell