A Msg#: 4233 *Programming* 04/12/90 22:12:42 From: TRACY ALLEN To: TOM JENNINGS (Rcvd) Subj: REPLY TO MSG# 4105 (SPREADSHEET) The extRAM fits into the option ROM socket, not into the socket used by MSplan. It is too bad that they didn't give us the option of replacing MSplan with something different. Anyway, if you do program development using the Cleuseau/ROM2, you could keep your copy of ROM2 in the extRAM, and then load in some other ROM or just use the extRAM as general purpose memory at some other time when you're not using the Cleuseau. Did you know that the ROM2 will assemble code directly into option ROM? So if you have the extRAM in the option ROM socket, with Cleuseau/ROM 2 loaded into it, then you can use the empty 16K of space for your own programs (like the xmodem thing). That's right, if you didn't know already, the Cleuseau/ROM2 occupies only 16K in a 32K address space! What you do is just ORG your assembly code at some address below 8000h. ROM2 will attempt to assemble it there, and if you have RAM instead of ROM in that space (extRAM! that is), the assembler will succeed and you can run your code directly from there. You have access to all the documented routines in the ROM2. Not only that, you have access to all the standard ROM routines too. It is not documented in the manual, but you can use the CSR op-code (Call Standard Rom) in your source any time you want to call the standard ROM. The ROM2 will take care of all the -More- overhead of getting smoothly from option ROM and back--handling interrupts, the return stack, everything. It uses Tom Bennetts "guardian" code. BTW, these are things I learned from Paul Globman, who knows a _lot_ about both the Cleuseau/ROM2 and about the T200. He signs on here on this board occasionally, so you might leave him a message about things specific to the T200. -- Tracy <->, wd, elete, gain, eply, ext, or top?