Relay Computer Quick Usage Guide
This diagram shows the discrete LEDs:
The 8-digit data display shows to contents of the memory address shown on
the 2-digit address display. If the upper 16-bits of memory contains a halt
instruction (wra and wrb bits both set), then it's assumed that the memory
address is being used for a data byte, so only the lower byte and the lower
bytes of the next three addresses are shown. Decimal points are illuminated
in this mode:
00.00.00.00 Showing data bytes of four addresses
If memory contains any other instruction, then the full 32-bit
instruction is shown. Decimal points are off in this mode:
00 00 00 00 Showing instruction in a single address
Data / Address entry
Type 2 - 8 hex digits. Use ← key for backspace. Backspace all
digits to cancel data entry mode.
Save / Restore memory to non-volatile storage
2nd DEC Restore memory from non-volatile
2nd INC Save memory to non-volatile
(Only lower 128 addressess are saved/restored).
Modify display address
<address> ADR Set Address
INC Increment address
DEC Decrement address
Write data to memory
<data> DEP Write data (deposit) to current address
<data> INC Write data to current address and
<data> DEC Write data to current address and decrement
Change operating frequency
2nd 0 Speed controlled by knob
2nd 1 Slowest
2nd F Fastest
The default speed is 5
<address> STP Set current Program Counter
STP Single Step
<address> RUN Set Program Counter and run
RUN Run until halt instruction or STP key
Input and output bits
There are four output bits implemented as relay flip-flops. Each of
these bits is available externally as relay contacts. Both the normally
open and normally closed contacts are wired to the connectors.
12V and ground are wired to external connectors also. These may be used
along with the output relay contacts to control small lamps.
There are four input bits wired to connectors. It is expected that
switch closures are connected to these. When a switch is closed, the input
registers a '1'. When a switch is open, the input registers a '0'.
If I/O is not needed, the outputs may be connected to the inputs to
produce an extra programmable register implemented with relay flip-flops.