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| MS11M8K | MS11M32K | MS11M64K | BS2-IC | BS2SX-IC | |
| Price | $34 | $62 | $75 | $49 | $59 |
| Starter Kit Price | $49 | $77 | $90 | $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 | 32K 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 |
It's true, the BASIC Stamp is a fast machine-- but it has 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!
