MicroStamp11 Family compared with BASIC Stamp II Family

MS11M8K MS11M32K MS11M64K BS2-IC BS2SX-IC
Price $34 $42 $45 $49 $59
Starter Kit Price $53 $60 $63
$149
$159
Microcontroller Motorola
6811HC11D0
Motorola
6811HC11D0
Motorola
6811HC11D0
Microchip PIC 16C57 Scenix SX28AC/SS
Program Execution Speed 50,000*
instructions/sec.
50,000*
instructions/sec.
50,000*
instructions/sec.
4,000 instructions/sec. 10,000 instructions/sec.
Processor Speed (MHz) 2.0 (2.4576 on Turbo version)
2.0 (2.4576 on Turbo version)
2.0 (2.4576 on Turbo version)
20
50
Program Memory Size 8K Bytes
32K Bytes
64K Bytes
2K Bytes
(500 PBASIC instuctions max.)
8 programs x 2K Bytes ea. (16K Bytes) (up to 4,000 lines of PBASIC code)
RAM Size 192 Bytes for variables and stack + 64 for I/Os
192 Bytes for variables and stack + 64 for I/Os
32K Bytes for variables + 192 for stack
+ 64 for I/Os
32 Bytes (6 for I/Os and 26 for variables)
32 Bytes (6 for I/Os and 26 for variables)
Scratch Pad RAM included above
included above
included above
n/a
63 Bytes
Number Inputs/Outputs 16
16
16
16
16
Current @5v 15 mA Run
6 mA Standby
25 uA Sleep
15 mA Run
6 mA Standby
25 uA Sleep
15 mA Run
6 mA Standby
25 uA Sleep
8ma Run/100 uA Sleep
60ma Run/200 uA Sleep
Number of Interrupts 2 external
18 internal
2 external
18 internal
2 external
18 internal
0
0
Source / Sink Current per I/O 20 mA / 20 mA
20 mA / 20 mA
20 mA / 20 mA
20 mA / 25 mA
30 mA / 30 mA
Connector Socket 20-pin multiple-choice
20-pin multiple-choice
20-pin multiple-choice
24 Pin Dip
24 Pin Dip
PBASIC Commands programmable in BASIC, assembler, C, Forth, or Pascal
programmable in BASIC, assembler, C, Forth, or Pascal
programmable in BASIC, assembler, C, Forth, or Pascal
36
39
PC Programming Interface Serial Port (9600 baud)
Serial Port (9600 baud)
Serial Port (9600 baud)
Serial Port (9600 baud)
Serial Port (9600 baud)
Maximum serial Interface speed (baud) 9600
38400 (Turbo)
9600
38400 (Turbo)
9600
38400 (Turbo)
9600
9600
Hardware UART
yes
yes
yes
no
no
SPI port yes
yes
yes
no
no
Number of
Input Captures
3 or 4
3 or 4
3 or 4
none
none
Number of Output Compares 4 or 5
4 or 5 4 or 5
none
none
$45

*approximation based on an average of 10 cycles per SBASIC instruction

It's true, the BASIC Stamp is a fast machine-- but it needs to be!  The CPU has to fetch the user program serially out of external memory (serial EEPROM), one instruction at a time, before executing it.  On the other hand, the CPU on MicroStamp11 executes the user program directly from parallel memory (called "execute in place")--  no time-consuming fetching and translating required!
     To make matters worse on the BASIC Stamp, there are no on-chip hardware subsystems to take care of commonly needed tasks such as communications, event-timing and counting, interrupts, or pulse generation--  the CPU has to do everything itself by emulating these functions in software.

     While the CPU on MicroStamp11 runs at just a tenth the speed (or less), it accomplishes a lot, because it has a whole "team" of intelligent hardware to work with!  The CPU acts as the leader, or coordinator, and delegates various tasks to each of the hardware subsytems.  For example, MicroStamp11 could be programmed to simultaneously receive a text string from a user at a terminal and then transmit a reply to the terminal via the UART, fetch some data from an analog-to-digital converter attached to the SPI, keep track of the number of pulses coming from an encoder wheel fed to the Pulse Accumulator pin, decode an incoming IR transmission on an Input Capture pin, control the speeds of a couple of motors via Output Compare pins, update its software time-of-day clock every millisecond, and generate an alarm tone on an Output Compare pin when the time-of-day matches a preset time.  It could drop by each of the subsystems to see if results are available (called "polling"), or it could let subsystems interrupt whenever they have results (called "interrupting").  This kind of hardware architecture lends itself well to multi-tasking, which is something the BASIC Stamp just can't do.  You would need a half dozen BASIC Stamps or more to do all the above tasks simultaneously, and then you would have to network them together, using one as the group leader--  it all gets complicated (and expensive) very fast!

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