<<5>>  ATOM--8

 

ATOM-8 CPU(by 富崎新(Tomisaki.A),1973) 180215g-190523g Netobi.Nao

==========================================================================

ATOM-8 was 8 bit, minimal Neumann architecture, bit serial processing

CPU, designed by 富崎新(Tomisaki.Arata(japon)).

This was published in monthly magazine "トランジスタ技術"(Transistor 

Technology) 1973/05 to 07 issue. And re-published in "つくるコンピュータ" 

(Homebrew Computer) 1976 issue.

 

  

 

Architecture:

============= 

8bit/Word, 1-address 

3bit-OpCode, 5bit-Address(=ProgramCounter), 1-Accumulator

32word(=Byte) main storage

Von Neumann architecture, Hard-wired bit serial processing

2-phase(Fixed)/Instruction: I-Fetch, I-Execution

 

 

 

Major Component(#bit):

====================== 

Acc(8) : Accumulator ShiftRegister

AdderExtendUnit(1) : FullAdder and Extra function unit

MainStorage(1x8x32) : Serial R/W storage

AddrSelector(5) : Select PC xor AR for MainStorage Address

OrderReg(8) : ShiftRegister for Instruction

InstructionReg(3) : MSB 3-bit of OR

AddressReg(5) : LSB 5-bit of OR

ProgramCounter(5) : 

SubProgramCounter(4) : Under PC counter for Serial process

                       MSB is Instruction phase(Fetch/Execute)

                       Other is bit serial(8) counter(virtual?)

Other: Instruction Decoder and Other control logic

 

  

 

Instruction:

============

0: HALT (noAddr)

1: ShiftRL4bit (noAddr)

2: Subtract : Acc = Acc - [Addr]

3: Add : Acc = Acc + [Addr]

4: Load : Acc = [Addr]

5: STore : [Addr] = Acc

6: BranchNoMinus : PC = Addr if Acc.MSB is 0

7: Reset Overflow(carry)Flag (noAddr) : unknown

  

 

 

Other:

======

 

Using 25 TTL-IC & 1 MOS RWM(Intel/1101A) 

 

1973/05 issue was CPU hardware design 

 

1973/06 issue was about General software, very little ATOM-8 software!

  

1973/07 issue was about Peripheral and Supplementary

 

Wiring diagram: I don't remember what my writing meant to blueprint!

 

In 1974, I made it based on this article, but I did not use it for long 

time!

Because program area was too small, even most of small program could 

not be entered! Then ceased to be used.

Therefore, I planned extension to 12-16 bit/word and extension to 

parallel processing. That became knowledge base of next year's EASY-4

CPU production.

And then, ATOM-8 was disassembled, and it's  front panel was cut and

diverted to EASY-4 panel!

Therefore, ATOM-8 entity disappeared except CPU-Board in 1975.

I did not take ATOM-8 photo, so I created image by imagination(see 

My ATOM-8 Supposed Image 2018/02h).

 

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