The ICT 1301 Resurrection Project.
The Order Code
The hardware order code for the 1301 was a set of decimal
( Yes Decimal ) Codes which are tabulated below.
The order code was designed to cover decimal arithmetic and ( due to the age of its design )
Old Sterling calulation functions as well.
Yes that's Pounds, Shillings and Pence calculations in hardware.
Order Code Listing
Key to graphic displays, the Store ( IAS ) is represented in blue
The three data registers A,B and C are all 12 decimal digits long, and the
Mill is where the basic math unit performs simple addition and other basic functions.
The 1301 used a Binary Coded Decimal display of the contents of its registers, These registers were 12 digits long. The order code was also based on a decimal decode, and although some orders were 12 digits in length the majority of the orders were only 6 digits long. Therefore two 6 digit instructions were able to fit into a whole 12 digit word.
here we have an example of the 6 digits spread over the first control register,
and the significance of the bits within the register
Where the indicator test bit is set the indicator is specified by the two digits
in the Function field, a set indicator will cause the program to branch to the address
in the instruction
List of Indicators
Grouped by device
Most computers need to observe several basic steps to run, these are:-
FETCH INSTRUCTIONS (from Store)
FETCH DATA (from Store)
WRITE DATA (into Store)
STEP TO NEXT INSTRUCTION
To see how all these concepts came together here is a prototype animated display of the
machine fetching some instructions from store ( IAS ) and obeying them, although this is a first
attempt it would seem we have the basic's for further explanation of instructions using simple animation
The loop bieng obyed is as follows:-
Loc: Fn: Addr : Narrative:-
and then the data paths opening and closing to show the data flow in the computer.
The whole thing is repeated five times, at a rate of about 2 frames per second.
If the Animation has stopped, press the refresh button to restart it.
(Designed for 640 x 480, 800 x 600 or 1024 x 768 Resolution) a 'POPUP' and 'FRAMES' free zone
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