1. SAPC Hardware Pentium CPU (or 486) 4M usable memory no hard disk; boot from floppy no keyboard or monitor or mouse COM2 serial port: used for console i/o COM1 serial port: used for remote gdb LPT1 parallel port: not used timer device PIT: used for periodic interrupts reset circuitry: used for remote reboot

2. SAPC Programming Environment More info at: www.cs.umb.edu/ulab/ www.cs.umb.edu/ulab/sapc_programming_ env.html http://www.cs.umb.edu/ulab/mtip.intro.html

3. SAPC Memory Layout 0 - 0x9 FFFF : ordinary memory 0xA 0000 - 0xB 0000:video memory 0xF 0000 - 0xF FFFF:BIOS 0x10 0000 - 0x3F FFFF: user memory System area Sys Area code data stack 0 0x00100000 0x003FFFFF

4. The “old” Picture Sun Blade (OS is UNIX) emacs or vi mtip ulab (OS is UNIX) Putty/SFTP or SSH Communications via Internet IBM Compatible SAPC’s in S-3-142 (OS is “Tutor” not UNIX) COM2 COM1 Reset Server

5. Serial Port Connection to Port Master SAPC #COM Ports Port Master Ports 1COM2S29 2COM2S28 3COM2S27 4COM2S26 5COM1, COM2S24, S25 6COM1, COM2S22, S23 7COM1, COM2S20, S21 8COM1, COM2S18, S19 9COM1, COM2S16, S17 10COM1, COM2S14, S15 11COM1, COM2S12, S13 12COM1, COM2S10, S11 13COM1, COM2S8, S9 14COM1, COM2S6, S7

6. SAPC Software BIOS –burned in ROM –available at power-up –initializes the hardware, loads and start the Tutor bootstrap Tutor (and its bootstrap) –loaded from floppy disk into RAM –runs in kernel mode –initializes more hardware, switches from 16-bit real mode to 32-bit protected mode

7. The “new” VM Environment

8. SAPC Software Support Directories $pcinc – headers $pcex – C examples $pcbook – for S&S 1 chapters 2 and 3, assembler examples $pclibsrc – sources for the SAPC support library 1 “ The IBM Personal Computer from the inside out” by Sargent and Shoemaker

9. Protected mode vs Real Mode 32-bit protected mode means we can use 32-bit addresses; addressing up to 4G locations; w/memory protection; virtual memory 16-bit real mode means we can use 16-bit addresses, addressing up to 64K locations convention: –AX: 16 bit register –EAX: 32 bit register

10. Building a program for SAPC Follow 1st steps listed in www.cs.umb.edu/ulab –login to ulab –add “module load standard ulab” to.cshrc –examples in directory $pcex Use a makefile in $pcex to make the SAPC executable e.g. ulab(65)% make C=test test.lnx The suffix “.lnx” is short for Linux, since we are using a Linux-originated executable format Program compiled using the i386-gcc compiler

11. Download programs to SAPC Execute mtip to download a.lnx file to a SAPC ulab(66)% mtip -f test.lnx Hit CR to get its Tutor prompt. ~d will download the test.lnx file to VM In the new VM environment, ~r to reboot the SAPC does not work. You need to click on the “Send cntl-alt-del to VM” button to reset the tutor VM.

12. Other mtip Commands Depending on the functions(e.g. remote gdb), may want to download the program to the SAPC For example: download test.lnx to SAPC VM –ulab(66)% mtip -f test.lnx –hit CR to get its Tutor prompt. Follow with ~d to download the program. Additional mtip commands and their functions can be found in www.cs.umb.edu/ulab/mtip.intro.html

13. More mtip Commands The ESCAPE CHARACTER: ~ This is the escape character that MUST precede ALL COMMANDS. (if you need to change it, use the -e argument to mtip) The Most Important Commands: (uppercase or lowercase: ~Q or ~q for quit, etc.) ~h - Help. Will display all commands possible. ~q - quit mtip back to UNIX. ~d - This command will download the file argued in the command line by the - f. ~f - This command will allow you to specify the download file from inside mtip (same effect as -f on command line) ~\char - Send one char to board "as is” ~! - This will allow you to issue a UNIX command to a subshell.

14. Notes Extended memory - memory above 1MB All Intel processors above 286 starts out in real mode( 20-bit ~1MB of address space)