CompuServe Messages

68010

    21-Apr-93 01:21:38
Sb: #34249-68010
Fm: Ronald B. Romine 70322,1525
To: Jim Nowlan 72163,1455
The 68010 is the more slimlined version of the 68000. The math routines have been improved — increasing the ADDITION by 15%, and the DIVISION by 50%. This will increase the speed of software that uses math (such as LHA, ZIP), but will not be as noticable with software that uses heavy graphics. The 68010, is not much faster, and "overall" system preformance will be incresaed only 5% to 15%. — The REGISTERS are now "vector based", allowing them to be moved from the CHIP memory into the FAST memory. If the system has *true* FAST memory (not the Slow-Fast found in the A501-Slot), it may help the CPU which could still gain access to the registers, when CHIP memory is being used by the graphics chips. Not all programs support the (vector based registers) VBR feature, some programs are hardcoded to "look at" only the default location and will crash if the registers are moved. A program like "FASTVBR" is needed to move the VBR (vector based registers) to FAST memory. — There is also the "LOOP mode", which resembles the 68020's ICACHE. The loop mode is totally transparent and does NOT need software to activate it. It will increase the speed of moving data between different locations in RAM. This will "speedup" RAM-disks, the moving of data between FAST and CHIP memory, and the moving of data from buffers to its final location. Loop mode, should also increase the speed of CPU based hard drive interfaces. Your AdIDE will become faster with the 68010 installed. Try checking the IDE speed with the 68000, then again with the 68010. — The only weakness is the "MOVE SP" instruction. This command was changed from a "USER" (program accessable) to a "SUPERVISOR" (OS level?) command to support an earlier method of multitasking referred to as "virtual machine" (VM). This "VM" allowed a OS to "partition" a computer into multiple areas to allow muliple users or programs at the same time. ALL 680×0 CPU's that came after the 68000, share this change. If the "MOVE SP" causes problems under the 68010, it will cause the same problems uder the 68020, 68030, & 68040. The change was believed to be needed because as a USER level command, it would have allowed programs to access the system pointers when the pointers were still being used for the "other" user's area. The "MOVE SP" command is replaced by using the programming code called "GET CCR". The change in "MOVE SP" and the "GET CCR" option, has been know since 1985. Unfortunately, some software is still written to use the "MOVE SP" command, making it "68000-only". The program "Decigel", and others like "SuperDecigel" can patch the system to capture this programing error and substitute the "GET CCR" code, allowing 68010/020/030/040 CPUs to run the offending software. Ron. – ap'ing with AP. (Eagles may fly, but weasles aren't sucked into jet engines.)