[ot?] request for comment

I have a CARDIAC, perhaps I could scan the booklet for you. Or would you like to build something unique? I have a similar project called SIMPLEX which is a PDP/CARDIAC/uP inspired instructional computer architecture. --Chuck At 03:27 PM 8/12/01 -0700, you wrote: > I was going to write a simulator for Bell Labs "Cardiac" (cardboard > slide the slides and move bits be the cpu your self) computer, but all > I can find is the Instruction Set, none of how the instructions are > implemented. > > So, I decieded to write my own... > Here is the instruction set, I thought it best to consult with you > all before beginning to code. What > do you think? > Opcodes > > 0 1 2 3 4 5 6 7 > Z N o1 o2 o3 > ================================================================= > Z N 0 0 1 i r r get copy (indirect) register rr to acx > > Z N 0 1 0 i r r put copy (indirect) acx to register rr > > Z N 0 1 1 o o o Mathop > > 0 0 0 nop > 0 0 1 add acx + acy ==> acx > 0 1 0 sub acx - acy ==> acx > 0 1 1 and acx & acy ==> acx > 1 0 0 exor acx xor acy ==> acx > 1 0 1 or acx | acy ==> acx > 1 1 0 cmp acx cmp acy set Z and N > 1 1 1 cpz acx cmp 0 set Z and N > > Z N 1 0 0 p p p inp copy port ppp ==> acx > > Z N 1 0 1 p p p out copy acx ==> port ppp > > Z N 1 1 0 i r r swp acx ==> (ind) Rn == > acx > > Z N 1 1 1 0 o o acx op group > > 0 0 0 not r1 <== ! r1 > 0 0 1 shl Shift left > 0 1 0 shr Shift right > 0 1 1 inc Increment r1 <== r1 + 1 > > Z N 1 1 1 1 o o Jump Group > > 1 0 0 jmp ind [pc] pc <== [pc] > 1 0 1 jsr ind [pc] R2 <== pc , pc <== > [pc] > 1 1 0 rtn pc <== R2 > 1 1 1 Halt,reset [pc] <== 0 > > Zero and Negative flags > > On execution of the cmp and cpz instructions the Z and N flags are > set, following instructions can test these flags and choose to execute > or not. > > Z N Meaning > 0 0 Execute if acx was positive on test (acx > 0 / acx > acy) > 0 1 Execute if acx was negative on test (acx < 0 / acx < acy) > 1 0 Execute if acx was zeron on test (acx = 0 / acx = acy) > 1 1 Always execute > > > Registers > 00 r0 acx 1st operand > 01 r1 acy 2nd operand > 10 r2 ptr Pointer register > 11 r3 pc Program Counter > > > here is an example of an assembled program.... > > Assembly of a simple program > > org $10 ; program starts at 10 10 > > get ind pc ; load value1 acy 10 11001111 00010000 > adr value1 11 00011001 00010001 > swp acy 12 11110110 00010010 > > get ind pc ; load value2 acx 13 11001111 00010011 > adr value2 14 00011010 00010100 > > add ; sum values 15 11011001 00010101 > > put ind pc ; store sum 16 11010111 00010110 > adr sum 17 00011011 00010111 > > hlt ; end of program 18 11111111 00011000 > > value1 byt 19 00011001 > value2 byt 1A 00011010 > sum byt 1B 00011011 > > > end ; end of code > > > > I know, it only has 256 words of 8 bit memory, but isn't this as much > as some of the early machines? >