Jade Computer Products - S-100 Bus Probe
Today with the use of multi-contact USB based logic probes and
PC-based software its easy to forget how useful this S-100 bus probe by Jade
was. There were other single LED hand held logic probes but this one
was unique. Its size was a bit overwhelming and it did not do well at
fast clock speeds but it often helped quickly identify a hardware problem on
the bus.
The BUS PROBE provided an inexpensive tool for troubleshooting of CPU
boards, S100 Temporary Bus Masters (such as disk controllers), as well as
entire systems. Master boards generate most of the IEEE S100 bus signals.
The BUS PROBE allows the user to quickly monitor these IEEE 696 S100
signals. Since very few front panel boards provided for display of the
entire S100 bus, and most systems don't have front panels at all. The
BUS PROBE provided a cost effective and easily installed means for
troubleshooting.
The BUS PROBE was a LED display board designed to be inserted into the S100
bus. This board was mostly passive to the S100 bus. It monitored each of the
S100 signal lines (with minimal loading) and displayed the signal logic
level on the corresponding LED. In most cases the LED was ON when the S100
signal was ASSERTED. For address and data lines this is a logic 1 or high
TTL level. Signals like INT* were ASSERTED as a logic 0 or low
TTL level. The BUS PROBE was capable of displaying all IEEE 696 S100
signals. This board functioned in most S100 computer systems designed
previous to the IEEE specification.
The BUS PROBE can be divided into two sections. The lower half of the board
contains the S100 bus interface and display driver circuitry. The lower half
of this board is about the same size as a standard SI00 board. The upper
half of this board contains the display area. The display area has been
double silkscreened to enhance the LED display. This section of the board
extends above the top of other boards. This makes the display area visible
when plugged directly into the S100 bus.
This product allows selective viewing of certain bus cycles. By switch
selection the user can display any one or combination of the following bus
cycles: M1 instruction fetch, memory read, memory write, port input, and
port output.
The manual for this board can be obtained
here.
Other Jade
S-100 Boards
Bus Probe
8K Static RAM
Z80 CPU 64K RAM
FDC
1P2S
PSIO
This page was last modified
on
10/25/2013