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:

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

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

5. Serial Port Connection to Port Master
SAPC # COM Ports Port Master Ports
1 COM2 S29
2 COM2 S28
3 COM2 S27
4 COM2 S26
5 COM1, COM2 S24, S25
6 COM1, COM2 S22, S23
7 COM1, COM2 S20, S21
8 COM1, COM2 S18, S19
9 COM1, COM2 S16, S17
10 COM1, COM2 S14, S15
11 COM1, COM2 S12, S13
12 COM1, COM2 S10, S11
13 COM1, COM2 S8, S9
14 COM1, COM2 S6, S7

6. SAPC Software BIOS Tutor (and its bootstrap) 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. SAPC Software Support Directories
$pcinc – headers
$pcex – C examples
$pcbook – for S&S1 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

8. The “new” Virtualized SAPC Environment
ulab.cs.umb.edu
(Unix)
SSH
Secure
Telnet
tutor-vserver
(Linux)
SCP
Your home
directory
and your
cs444 directory
COM1
COM2
tutor
(Tutor)
Virtual Development System
Virtual Embedded System

9. The “new” Virtualized SAPC Picture
Use the UNIX server (ulab) to edit your source files, compile and assemble them.
Then transfer the executable and C code to an UNIX VM (tutor-vserver) running on a PC.
Use the UNIX VM (tutor-vserver) as a server for downloading code to the tutor VM
Use the UNIX VM (tutor-vserver) as a terminal locally attached to tutor VM’s COM ports and issue commands to the tutor VM

10. The “new” Virtualized SAPC Picture
Instructions on how to set up the Virtualized SAPC Environment:
VMWare Workstation for PCs:
Modifications for VMWare Fusion on MACs:

11. Building a program for SAPC
Follow 1st steps listed in
login to ulab
add “module load standard ulab” to .cshrc
Copy my files in /courses/cs444/f18/cheungr/examples to your cs444 directory
cd test_dir
Use the makefile in test_dir 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

12. Transfer programs to tutor VM
Transfer the files to the tutor-vserver VM:
Log into tutor-vserver VM using the credentials provided
Transfer files from ulab to tutor-vserver VM:
vserver$ scp .
Download to tutor VM

13. Running the test program on tutor VM (cont’d)
Download the test.lnx file to the tutor VM
At the tutor-vserver VM, enter
vserver$ mtip -f test.lnx
After connecting to the tutor VM, you’ll see: ….
Using board #1
Reboot the tutor VM by selecting the “Send Ctrl+Alt+Del” button at the tutor VM. You’ll see:
Please type <CR> to confirm console settings:
Hit <CR> at the vserver VM to get the Tutor prompt. Enter ~d to download the test.lnx file to the tutor VM
After downloading, Tutor prompt will appear again

14. Running the test program on SAPC VM (cont’d)
To execute the program, type
Tutor> go
Follow the program’s directions. It should finish up quickly and hand control back to Tutor. You will see Tutor prompt again.
You can run it again by issuing command “go ”
Type “~q” or two ctrl-Cs to quit out of mtip

15. Other mtip Commands
To set up for remote gdb, follow the instructions in:
Additional mtip commands and their functions can be found in

16. 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.

17. 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

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