Radio Shack CCR-81 Quick Reference Guide

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RESTART
Restart Hardware Inlerrupt.
The processor is lOitialized (required after power-on) 10 start
prClgram executlon. The slarting address is Iocaled Irom the
resta" vector.
SEX
S~n .Extend~.
This Instruction transforms a Iwos complemenl8-bi1 value Ifl
aecumulator B into a 1wos compiemenll6-tlII value 10 the D
aecumulator .
SSC
Sublraet with Borrow.
Sublr~ the contents 01 a memory Iocalion and the borrow (in
lhe C bit) 'rom the conlents 01 the designaled 8-bit regisler and
places the fesult ln thal rogister. '
SEmP
Tells the assembler la set the direct page
Example: SETDP $20
Tells the assembler to set the direct page to $20
ROL
Rotate left.
~ates aH brts 01 the operand one place 18ft through the C (cany)
ROR
Rotale RighI.
Rotales ail bits 01 the operand one place nghl through the C
(carry) bit.
RTl
Return lrom Interrupl.
The seved machine state is r8CQvered !rom the hardware slack
and control is relurned tothe interrupted program,
RYS
Return Irom Subroutine.
Program control is returned lrom the subroutine 10 the calling
program. The retum address is pulled lrom the slack.
SUR
(S-bll) Subtract Memory lrom Register.
Subtr8cls the value in a memol)' location lrom the contents 01 a
deslanated 8-bit rogister. The C (carry) bil represents a borrow
and Ts sel 10 the inverse 01 the resullll'19 binary cany.
ST
(8-bil) Store Register into Memory.
Writes the conteotsof an S·bit register intoa memory localion.
ST
(l6-bit) Store Register into Memory.
Writes the contents al a 16-bit register intotwo consecutive
memory locations.
OR
Inclusive OR Memory lOto Register.
Perlorms an inclusive OR operation between the contents 01
accumulator A or B and the contents of memory location M and
the resull is store<! ln accumuiaior A or B.
PSHS
Push Reglsters on !he Hardware Staek.
Ail, sorne, or none of the processor registefs are pushed onto the
hardware staek(Wlth the exception of the hardware stock
pointer)
PSHV
Push Reglsters on the User Stacle
Ail. some. or none 01 the pfOcessor registers are pushed onlo the
user stack (wlth the exceplion 01 the user stack pointer).
PULS
Pull Registers Irom the Hardware Stack.
Ali. sorne,
or none 01 the proccessor registers are pulled lrom
hardware stack (with the exception olthe hardware stack
pointer).
NEG
Nagate.
Replaces the operandwith ilstwos complement TheC (carry)
bit represents a borrow and is set 10 the IflVerse of the resultlog
binary carry
NOP
No Operation.
This ioslructJOn causes ooty the programcounter 10 be
lnaemenl&d. Nootherregislerormemory locations are affected
ORec
Inclusive OR Memory Immediate into Condition Code Register.
Pertorms an inclusive OR operation between the contents 01 the
condition code registers and the Immediate value, and the resul
is placed ln the condition code register. This Instruction may b&-
usad 10 set interrupt masks (disable inlerrupts) or any other
bit(s),
ORG
Tells the assembler where to begin localing the op code in
memory.
ElIlample: ORG $3FOO
This tells the assembler 10 k>cale the program op code
beglnnlng al address S3FOO. When Ihe assembler arrives
at ihe new OAG command, il will begln loesling program
code al the new address. An OAG statement must nol
have a label.
PVLV
Pull Registers lrom the User Stack.
Ali,
some, or none olthe processor regislers are pulled Irom the
user stack (wilh the exception 01 lhe hardware stack poinler).
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Radio Shack CCR-81 Specifications

General

Brand	Radio Shack
Model	CCR-81
Category	Desktop
Language	English