Intel MCS-80/85 ES77 C2760S 102, ES7A Le?, E87B C2760S 104, 98se, 0882 as, 112, B888 FB, 088E

Models: MCS-80/85

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CRT and Cassette Code (Cont'd)

ISI 5-I I

8080/8085

ASSEMBLER,

\/1, 8

1100ULE

 

 

PAGE

4

8085 SERIAL I/O NOTE APPENDI:~

 

 

 

 

 

 

LO(:

OB!

SEQ

SOURCE STATEMENT

 

 

 

 

eS77 C2760S

102

.INZ

CO2

 

 

 

 

eS7A 25

le?

[iCP

H

 

 

 

 

e87B C2760S

104

.JNZ

CO2

 

 

 

 

087E

7,7

1as

STC

H, ,~

,: SET ~IHflT

~HLL EVENTUALLY BECONE

A STOP BIT

8a7F

79

106

MOil

,: ROTATE CHARACTER RIGHT ONE BIT,

 

98se

1F

1137

RAR

 

; \, MOVING NEi<:T r,ATA BIT !NTO CARRY

13881

4F

1e8

~10V

C,R

 

 

 

 

0882 as

1139

DCR

e

,; CHECK IF

CHARACTER (At-I[i

STOP BIHS) DONE

0SS? C26Fe8

1113

JNZ

COi

,: IF NOL

CdJTPlIT ClJRRENT

CAF.:R'r'

 

e886 E1

111

POP

H

,: RESTORE STATUS AND RETURN

 

98S7 C1

112

POP

e

 

 

 

 

B888 FB

lE

EI

 

 

 

 

 

1.3889

C9

114

RH

 

 

 

 

 

 

 

115

 

 

 

 

 

 

116:I::IN CC!N';OL INPUT SUBROUTINE HAITS FOR A r::E'r'STROKEAND

:117; PET!JP.NS ~JIiH :3 8ITS IN PEG C

eeSA

F~:

118 eIN

DI

 

 

 

 

 

 

e88B E5

1!9

 

PUSH

H

 

 

 

 

 

eS8C

et.09

1.29

 

1'11l!

B,. enSI

.: C'AT"BITS TO 8E REACt (LAST F.:ETURNED IN CY)

088E 213

121

CIi.

PIN

 

:HAIT FOR s'me BIT TRANSITION

 

 

eB8F B7

122

 

ORA

H

 

 

 

 

 

eS90 FA8Eee

122

 

,TN

CIi

 

 

 

 

 

13891

2ACP.;)3

124

 

UU'

HALFBiT

 

 

 

 

 

e8?S

2[:'

125

C12

 

L

.';·JAIT UNTIL MIOfU OF START BIT

 

 

13897

C29608

:126

 

 

C!2

 

 

 

 

 

eS9A

25

127

 

 

H

 

 

 

 

 

e898

C2?~e:::

128

en

 

C!2

 

 

 

 

 

(!89E

28C82e

:129

 

8ITT Hlf

.; HA IT OUT BiT TH'lf

 

 

 

138Ft1

2[)

D3 CI4

 

L

 

 

 

 

 

e8A2 e2A1es

121

 

 

l'!4

 

 

 

 

 

 

 

.j 7'~'

 

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1388£

CAi0:::

 

 

 

CI4

: CHECr: SIL' LWE LEVEL

 

 

 

0889

213

154

 

 

 

 

 

 

aSA'!:17

 

 

 

 

:C'PTA BIT IN CY

 

 

 

 

H:?AE:

135

1::6

 

 

 

. CHERrmlE IF THIS IS FIRST STOP BIT

 

eSAC

CABt:B8

 

 

 

CIS

,: !F SO.' JUt1P OUT OF L.OOP

 

 

 

eSAF 79

 

 

i'10'··:

 

. ELSE ~OT'lTE INTO PHHIHL CHARACTER IN C

 

eSBe lF

1:'9

 

PAP

 

'ACe HOLl'S UP[iATEO CtlARACTER

 

 

13881

4F

141:1

 

1'10'·"

 

 

 

 

 

 

13882

1:10

141

 

 

 

.. E(llJALI2ES COUT AND CIN LOOP TH'lES

 

!?~~e~:

r:?:?E!~8

14~

 

 

 

 

 

 

 

 

i38Bf

E1

14:,

(15

 

H

 

 

 

 

 

l3::::E?

FE'

144

 

EI

 

 

 

 

 

 

08B:?

C9

14':.

 

REi

 

;CHARAC rEF.' CO~lPLEiE

 

 

 

 

 

146

 

 

 

 

 

 

 

 

 

 

14"

: '!"+"H"H't':t-'r:t-:+ +",""n"r"'f'Ho: f·H·+..h·~:·h..t:·i<:+·f:t':H':+..f*';t':H·f:n·t:'f.:n >t:h;;-'+:ljo,'"H:,t:!t';f.****:+::t:**'>j-.:i<·+:*

 

 

148

 

 

 

 

 

 

 

 

 

 

149

,;

THE' FC'L.!..mm·jGII)['E IS USEr',E','THE CASSETTE

INTERFACE.

 

 

 

lSi!

'

SUE:RO!)TINES TAFE' AN[' THPEIN ARE USEC; RESPECTIVELY

 

 

 

151

 

TO OUTPUT (IF RECEI'.,.'E AN EI!3HT Bli !.WTE (iF

[lRTA,

REGISTER

C

 

 

15::'

 

40LPS

T~E DAT~

IN EITHE;;'CAS£:

~:EGi5TERS

M., E:.I S.C

ARE tiLL

OEST~:O'r'E(;.

 

 

1S: rS!)·iO FOI!

 

nHCE THE Ni.i~lBER OF CYCLES PER TONE BURST

 

 

154

HALFC'r't"'EC'U

 

(:OETEPf'HNES TONE

FRmJENC~!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A1-51

Page 192
Image 192
Intel MCS-80/85 ES77 C2760S 102, ES7A Le?, E87B C2760S 104, 98se, 0882 as, 112, B888 FB, 118 eIN, Et.09 111l, 088E

MCS-80/85 specifications

The Intel MCS-80/85 family, introduced in the late 1970s, is a seminal collection of microprocessors that played a pivotal role in the early days of computing. The MCS-80 series, initially targeting embedded systems and control applications, gained remarkable attention due to its innovative architecture and flexible programming capabilities.

The MCS-80 family is anchored by the 8080 microprocessor, which was one of the first fully integrated 8-bit microprocessors. Released in 1974, the 8080 operated at clock speeds ranging from 2 MHz to 3 MHz and featured a 16-bit address bus capable of addressing up to 64KB of memory. The processor’s instruction set included around 78 instructions, providing extensive capabilities for data manipulation, logic operations, and branching.

Complementing the 8080 was a suite of support chips, forming the MCS-80 platform. The most notable among them was the 8155, which integrated a static RAM, I/O ports, and a timer, tailored for ease of designing systems around the 8080. Other support chips included the 8085, which provided improvements with an integrated clock generator, making it compatible with more modern designs and applications.

The MCS-85 series, on the other hand, revolves around the 8085 microprocessor, which provided a more advanced architecture. The 8085 operated at clock speeds of up to 6 MHz and came with a 16-bit address bus, similar to its predecessor. However, it introduced more sophisticated features, including an enhanced instruction set and support for interrupt-driven programming. These enhancements made the 8085 especially appealing to developers working in real-time processing environments.

The MCS-80/85 family utilized NMOS technology, known for its lower power consumption and higher performance compared to previous technologies like TTL. The family’s architecture allowed for easy interfacing with a variety of peripherals, making it a favorite for educational institutions and hobbyists embarking on computer engineering projects.

With its robustness, versatility, and affordability, the Intel MCS-80/85 microprocessors laid the groundwork for many subsequent microcomputer systems and applications. The legacy of this powerful family continues to influence modern microprocessor design, emphasizing the importance of reliable architecture in a rapidly evolving technology landscape.