This is the top level circuitry, which implements the loop structure of the algorithm, and holds the various variables. It also deals with user control - i.e. the user can reset, run, pause etc the computation. And, there's the important matter of output. The top level circuitry makes use of the various previously-described sub-circuits:
[master loop version Z 19 feb 2022.dig]
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|-----[3 x 10 bit multiply version E 19 feb 2022.dig] (purple)
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|-----[6 x 10 bit multiply version K 19 feb 2022.dig] (yellow)
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|-----[15 bit div 11 bit blocked version E 05 feb 2022.dig] (orange)
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| |-----[15 bit div 11 bit triple block version B 05 feb 2022.dig] (teal)
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|-----[6 bit div ten version I 06 feb 2022.dig] (green)
The 15 bit div 11 bit circuit (posted November 2021) is unchanged, but had to be re-drawn - to make it readable when printed even on the biggest available paper size! The 15 bit div 11 bit 'blocked' version divides the original circuit into five stages, each of which is implemented as a '15 bit div 11 triple block' circuit (which contains nine 74181 ALUs).
The complete master loop circuit is shown below - it's pretty much unreadable as it stands, so it's been divided into ten pieces.
The various pieces are interconnected with Digital 'tunnel elements'; in real life these will be interconnecting wires (ribbon cable?). Each of the ten pieces is a reasonable size (chip count) to go on a single board; so about ten boards for the master loop, plus three further boards, plus the 15 bit div 11 which is likely to be six boards in itself, giving something like 19 boards in total. I am thinking about 100 mm x 220 mm Eurocard types.
Anyway, here's the output (appearing at the bottom right (block 10)) of the master loop circuit - the circuit displays eighteen digits at a time; the left-hand nine digits are:
and the right-hand nine digits are:
And, yes, that's a decimal point after the first digit. In operation, the digits pop out in groups of three, and the display scrolls across (with said decimal point). The user has the option of making the machine wait after it has output eighteen digits; pressing RESUME, starts the calculation of the next batch of 18 digits (the final triplet is shown also):
[I've also included some circuitry to interface to a 3-digit printer(!) - this allows a printer to tell the machine to wait, whilst it prints out the triplet of digits (perhaps some sort of wood block contraption printing onto a long roll of paper would be fun...)].
I'll put more detail of each of the ten pieces of the master loop circuit in the next few posts.
Chip count (master loop only - not sub-circuits)
plus LEDs for diagnostics, and for output of the eighteen digits of the number - at least at the moment. Maybe I'll go for a vacuum fluorescent display of Nixie tubes.
The total chip count (i.e. including all sub-circuits) stands at 358. Perhaps appropriately for a machine of this nature, the most numerous chip is the 74181 ALU (55 required); the next most popular is the 7408 quad 2-input AND (39), followed by the 74367 hex non-inverting buffer - to drive diagnostic LEDs (38).
Thinking ahead, I guess something like 20 - 30 amps might be needed...
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