New answers tagged

4

You mentioned copying files into the %WINDIR%\SYSTEM\IOSUBSYS directory (including VMM.VXD), but nothing about the %WINDIR%\SYSTEM\VMM32 directory. The former, as the name suggests, contains only individual block device drivers (port drivers, VxDs for hard disks, CD-ROM drives, etc.). It’s the latter that is supposed to contain core VMM service drivers, like ...


224

Short explation The Windows NT 3.1 kernel is incompatible with enhanced 486 processors. Specifically, it is incompatible with 486 processors providing the CPUID instructions. Kernel debugging works fine with the 486DX-33 that was originally installed in the machine, and with the older non-enhanced core in a write-through Am486DX4-NV8T without SMM. If your ...


37

The early Apple Macintosh computers (original Mac, Mac 512K, Mac Plus) all came with a "Programmer's Switch" installed on the side. Yes and no. While the switch was there, it was on the inside, so, not really accessible. Only after being 'enhanced' with the so called 'Programmers Key Aid', a snap on after market piece of plastic, griping into the ...


24

The "programmer's switch" is more technically known as the NMI (Non Maskable Interrupt) switch. It is mapped to a priority 7 interrupt on the 68K CPU, which means it is capable of interrupting anything besides another priority 7 event. When pressed, the CPU saves all its state on the stack, switches to privileged mode, then looks at the interrupt ...


Top 50 recent answers are included