40 4O COMPUTE. MAY/JUNE. MAY/JUNE, 198O. <strong>1980</strong> ISSUE 4. 4. Review: Review: 6502 Software 65O2 Software Design, Review by Jim Butterfield by Leo J . Sca nlon Howard W. Sams & Co., Inc., by Leo J. Scanlon Howard W. Sams & Co., Inc., 27O 270 pp. $1O.5O $10.50 This 'T'hi s is is quite quile a pleasant book; it it makes good reading. . The title lilie is is misleading: m g: the Ihe book deals with wilh 6502 programming rather than software design. In In fact. ract , 1I rather r missed m the software design elements: clements: planning memory, memory. designing data structures, and testing/ debugging g methodology are a rc important impona nt concepts s for lor be· ginning g programmers. The book expends its s main efforts on the subjects of o f writing code and handling interrupts and a nd input/output inpUl/oUlpUl devices. The book bouk is oriented o enled towards IOwards the Ih e Rockwell AIM A I M 65 microcomputer, m r, but bur not t too lOa heavily. Users of other Olhcr systems will find it a worthwhile wonhwh ile reference of text. The book appears a ideal for a programming course textbook: textbook; it is well organized o and gets into serious s programming quite quickly. quickly, ChapterC 1I is partly historical, partly y an a n overview of popular microprocessors and partly panly a brief plug for the AIM A I M 65. There's a minor m problem where the aUlhor describes Ih e 6800/6 502 famil y as cha racler author describes the 6800/6502 family as character ized by b y novel memory-mapped architecture: re: in fact, , all microprocessors including Ih thee 8080 and Z-80 can aand do use mcmory memory mapped lIO. 1/0. And I rather wish that the illlroductio introductionn to the 6502 had mentioned ned its iis remarkable speed due to pipelining techniques - a factor r that sc sets it clearly y aahead ooff the earlier 6800. Chapter 2 gets into the 6502 instruction sel. set. Similar op codes are grouped aand discussed together, which helps to develop intuitive ideas of the machine's capabilities. Numerous us examples of coding arc are included. The slyle style is generally easy aand straightforward, rward , but beginners will still find it it slow going: Ih there's s a 10 lot 1 of malerial material 10 to gel get Ihrough. through. SSubroutines utines are covered in chapter I 4, ~, mostly y in terms oof f their mechanistic c characteristics. A couple of time deJay delay subroutines uti aare rc ggiven, aand it it's nice to to see ti liming m in g qquestions being \\'orked worked through mel meticulously. iculo usly. CChapters 4, 4, 5 and 6 get heavily y into coding questions: list aand lookups, mathematicall routines, and number-base conversion. Coding is isggiven through ughout out, , but lhe the emphasis is is oon n algorithms: lhe the aauthor Ulho r is is concerned wwith the methods behind d a pa particular a r kind oof f computation. A rather unusuall aalgorithm is is given for for calculating g the square rOOt root of ofan integer; it it's rather slo slow w compared lO to standard methods, but but readers may find it it an an interest interesting ing curiosit curiosity. CChapter i 7 ddiscusses interrupts. In Insixteen pages, it it's ha hard to tocome to togrips wit with h the whole qucslion question, , and a nd coding examples are arc cursory. ry. Chapter C 8 goes g"Oes into to considerable detail dctail on o n two input/output chips: the Ihe 6520 and a nd 6522. There are a re two appendices and a an index. II found the Iht: index rather sparse: for fur example, "relative " addressing" points you to LO page 40, bill but a more useful discussion d ion can be found on page 55. Coding g examples are arc written almost entirely in assembly b ly language. This T s is is quite q u readable, ble. but b ut II would vvo have preferred rred to see sec early y coding examples c XCl lllplcs complete with wilh their machine language nguag-e equivalents. s . The Thc overall organization ion of or the t book is good, g"ood t although a there are a rc inconsistencies within h in chapters: ( rs: some have summaries, some somc have references, rcfe rl:nccs. and some have neither. Chapter C r 2 has ait section entitled c ntitkd "How ': Ho\\, this chapter is arranged"; it appears on 011 the sixth si:..: page of o f the chapter, which seems Seems odd.. .. The coding is good, but there are a rc a few errors. On page 68. , the author suggests suggesls thai Iha t when n shifting shirting signed numbers to the left, , the programmer ll llllcr should arrangea to restore the sign bit in ill case it's shiltecl ift l'd out: O llt ; in fact, a change in the lhe sign n bit would be an overflow ow situation and there would be no repairing the damaged number. numbcr. Example 5-14 1 ~ ono n page 1391 :$9 should add a value e ofo f two to location Ti 22 rather than the value e of one shown; shown: most Ill alcrl alert readers ers will pick this kind oi of' thing up. u HardwareH re purists may wince at some of the terminology, such as use usc ofr the term "grounded'' " instead or of "logic zcro" zero" or ""low", . bul but everybodyy will understand rstalld wh;u what is mca meant. n t. The authorr has a conversational style and
MAY/JUNE, I JUNE. <strong>1980</strong>. I960. ISSUE 4. COMPUTE. 41 Grand Opening, ...• Systems Formulate Corporation. Your microcomputer information center. Miplot, The Intelligent We welcome you to \'ISII visi! our fLr first consumer commrcial sales center in the Umted United States_ States. Located in Palo Alto Ln in the ihe Town and Country Village Shopping Center. System:. Systems Formulaw Formulate features a full range of microcomputer systems and p~TLphe peripherals ral s for home or commercial use. . Dunng During the past few years since our founding in 1978. 197H. we hiNe have opI.'Ill.!d opened three retam retain stores in Japan stocking premiere Atl1I..'TLc
- Page 1 and 2: MAY / JUNE 1980 ISSUE 4. $2.00 MAY/
- Page 3 and 4: ow you can add high resolution grap
- Page 5 and 6: MAY/JUNE, I NE. 1980. I960. ISSUE 4
- Page 7 and 8: MAY/JUNE. 1Q80.ISSUE I960. ll. 4 CO
- Page 9 and 10: MAY/JUNE, I JUNE. 1980. ISSUE 4. 4
- Page 11 and 12: Take the mystery lake the mystery o
- Page 13 and 14: MAY/JUNE. I 1980 198O ISSUE .d. &.
- Page 15 and 16: MAY MAV/JUNE. I 1980 198O. ISSUE 4.
- Page 17 and 18: ' nrnauui J Authorized Dealers APRI
- Page 19 and 20: ■ ■ (:: Authorized Dealers •
- Page 21 and 22: MAY/JUNE, I 1980, I960. ISSUE 4. CO
- Page 23 and 24: MAY/JUNE. I 1980. ISSUE 4. COMPUTE.
- Page 25 and 26: MAY/JUNE. 1980 198O ISSUE 4. 4 COMP
- Page 27 and 28: THANKS FOR THANKS FOR THE MEMORIES.
- Page 29 and 30: MAY/JUNE. I 1960. 198O. ISSUE 4. CO
- Page 31 and 32: MAY/JUNE. . 198O. 1980. ISSUE 4. CO
- Page 33 and 34: MAY/JUNE, . 1980. ISSUE 4. 4 COMPUT
- Page 35 and 36: MAY/JUNE, MAV/JUNE. 1980 , ISSUE 4,
- Page 37 and 38: MAY/JUNE. MAV/JUNE. 1980 198O. . IS
- Page 39 and 40: MAY/JUNE. WAY/JUNE. 1980. I960. ISS
- Page 41: MAY/JUNE. I lQBO 1980. ISSUE 44. CO
- Page 45 and 46: MAY/JUNE, 1980 ISSUE A COMPUTE. 43
- Page 47 and 48: MAY/JUNE. J980 I960. . ISSUE 4. COM
- Page 49 and 50: MAY/JUNE. I 1980. 198O. ISSUE 4. CO
- Page 51 and 52: MAY/JUNE. , 1980 1960. ISSUE 4. A.
- Page 53 and 54: MAY/JUNE. 1980. 198O. ISSUE d. 4. C
- Page 55 and 56: MAY/JUNE. 1980 ISSUE 4 COMPUTE. 53
- Page 57 and 58: MAY/JUNE. , 1980 198O. ISSUE 4. COM
- Page 59 and 60: MAY/JUNE. 1980. 198O. ISSUE 4. 4 CO
- Page 61 and 62: MAY/JUNE, MAY/JUNE. 1980 198O ISSUE
- Page 63 and 64: , A rt\\>sALL ~\uS'ALL NEW from MIC
- Page 65 and 66: MAY/JUNE, I 193O 1980. ISSUE 4. COM
- Page 67 and 68: MAY/JUNE. MAY/JUNE . 198O 1980 ISSU
- Page 69 and 70: MAY/JUNE. MAY/JUNE, 19S0. 198O. ISS
- Page 71 and 72: 'VlA MAY/JUNE. Y I 1980 198O ISSUE
- Page 73 and 74: MAY/JUNE. MAY/JUNE, 1980. 198O. ISS
- Page 75 and 76: MAY/JUNE. 1980 I960 ISSUE 4 COMPUTE
- Page 77 and 78: MAY/JUNE. 1980. 198O. ISSUE A. COMP
- Page 79 and 80: MAY/JUNE. I 198O. 1980. ISSUE 4. CO
- Page 81 and 82: MAY/JUNE. 1980. 198O. IS$UE ISSUE 4
- Page 83 and 84: MAY/JUNE. 1980 198O ISSUE 4 A. COMP
- Page 85 and 86: MAY/JUNE. . 1980. 198O. ISSUE .SSUE
- Page 87 and 88: MAY MAY/JUNE. I lQ8o. 198O. ISSUE 4
- Page 89 and 90: MAY/JUNE, I JUNE. 1980 ISSUE 4, 4 C
- Page 91 and 92: MAY/JUNE.1980 MAV/JUNE. 198O ISSUE.
- Page 93 and 94:
MAY/JUNE. I 1980. ISSUE a. 4. COMPU
- Page 95 and 96:
MAY/JUNE. I 1980. 198O. ISSUE A. 4.
- Page 97 and 98:
MAY/JUNE. 1980. 198O. ISSUE 4. COMP
- Page 99 and 100:
MAY/JUNE. . 19So. 198O. ISSUE 4. CO
- Page 101 and 102:
MAY/JUNE. I 1980 I960. . ISSUE 4. 4
- Page 103 and 104:
MAY/JUNE. I 1980. 198O. ISSUE 4. A.
- Page 105 and 106:
MAY/JUNE, I JUNE. 1980. 198O. ISSUE
- Page 107 and 108:
MAY/JUNE. I 1980. 198O ISSUE 4. COM
- Page 109 and 110:
Said the Toolkit to the Word Proces
- Page 111 and 112:
MAY/JUNE. I 1980. 198O. ISSUE 4, 4.
- Page 113 and 114:
MAY/JUNE. I 1980. ISSUE 4. COMPUTE.
- Page 115 and 116:
MAY/JUNE. MAY/JUNE, 1980. ISSUE 4.
- Page 117 and 118:
MAY/JUNE, I JUNE. 1980. 198O. ISSUE
- Page 119 and 120:
■ ■ ' MAY/JUNE, AY/JUNE. 1980 1
- Page 121 and 122:
MAY/JUNE, I JUNE. 1980 198O. . ISSU
- Page 123 and 124:
COMPUTE. COMPUTE. TM The Journal Fo
- Page 125 and 126:
Dear MICRO-ED: Dear MICRO-ED: I wou
- Page 127 and 128:
Look To MTU For 6502 System Expansi
Change language