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A project log for Jelly

A minimal DIY 8-bit CPU made with TTL chips, to perform native brainfu*k language, extended to use three sequential access tapes.

alvaro-barcellosAlvaro Barcellos 02/12/2023 at 01:210 Comments

I'm doing a review of control lines, as jelly-six circuit get closer to go wire-wrap.

An alternative is resume dual function lines as:


TABLE U1, does internal control

U1 Lines
actiondescription
D0M0, address A8 for U4 (eeprom math)
vide table U4
D1M1, address A9 for U4 (eeprom math)
vide table U4
D2M2, address A10 for U4 (eeprom math)
vide table U4
D3CP5, clock (CP) for U5 (74hc574 latch)push a value into U5
D4OE2,  output enable for U2 (eeprom tape control)pull a value from U2
D5CP6, clock (CP) for U6 (74hc574 latch)push a value into U6
D6OE4,  output enable for U4 (eeprom math control)pull a value from U4
D7reserved

TABLE U2, does tapes control

U2 Linesactiondescription
L0, L1
00 is none, 01 is ONE, 10 is TWO, 11 is BOB
select which tape (none, one, data, bob)
L20 is forward (FW), 1 is backward (BK)
select the direction of step
L30 is read (RD), 1 is write (WR)
select the action
L4reserved

L5reserved

L6reserved
L7reserved

TABLE U2 special

special status, L0, L1, L2, L3
action
0000does nothing
used as delay
0010toggle a flip-flop to exchange forward and backward
does toggle tape (ONE or TWO) swap
used for extend exchange values
0001toggle a flip-flop to exchange tape ONE and tape TWO
does toggle direction (FW or BK) swap
used for solve loops
0011



TABLE U4, Math Control,

value (M0,M1,M2)operationvalueresult
0copy 00011011 00011011
1increase0001101100011100
2decrease0001101100011010
3clear0001101100000000
4shift left
0001101100110110
5shift rigth
0001101100001101
6negate0001101111100100
7mirror0001101111011000

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