MITS ALTAI 800

A Computer Concept Becomes an ex •ting reality. •••••••••• Contents •••••••••••••••••••••••••••

Introduction •....•.•.•.•••••••••••• 3 Altair Systems ...... •...... •.. 5 The Ultimate System ...... •....•.•. 7 The Possibilities ...... •....•....• S User Applications ...... •...... •.. 10 Altair Options ...... •..•...•.• ll Processor Description ...... ••.•. 14 Processor Instructions ...... l5 Questions &Answers ...... ••....•.• 17 1...... 1

Warranty: 90 days on parts and labor fOf assembled units. 90 days on parts fOf kits.

Prices, spec'ifications and delivery subject to change without notice.

6328 LINN, N.E .., P.O. BOX 8636, ALBUQUERQUE, N.M. 87108 505/265-7553

© MITS, Inc. 1974

PRINTED IN U.S:A. .. PIPE DREAM?

Not too long ago, the thought of an honest, full-blown, high-quality computer that sells for less than $500 would have been considered a mere pipe dream. Everyone knows that computers are monstrous, box-shaped machines that sell for 10's and 100's of thousands of dollars. Pipe dream or not, MITS, the quality engineering company that pioneered the calcu­ lator market, has made the Altair 8800 a reality. It is the realization of that day when computers arc accessible to almost anyone who wants one. I

The heart (and the secret) of the M ITS Altair 8800 is the Intel 8080 processor chip. Thanks to rapid advances in integrated circuit technology, this one IC chip can now do 3 what once took thousands of electronic components (including 100's of IC's) and miles of wire.

Make no mistake about it. The M ITS Altair 8800 is a lot of brain power. Its parallel, 8-bit processor uses a 16-bit address. It has 78 basic machine instructions with variances up to 200 instructions. That's enough to program all the traffic lights in a major city. And the MITS Altair 8800 Computer is fast. Very fast. Its basic instruction cycle time is 2 microseconds. Combine this speed and power with the Altair's flexibility (it can directly address 256 input and 256 output devices) and you have a computer that's competitive with most mini's on the market today. And sells for a fraction of their cost. FLEXIBILITY

The Altair 8800 has been designed to fulfill a wide variety of computer needs. It is ideal for the hobbyist who wants to get involved with computers. Yet, it has the power and versatility for the most advanced data processing requirements. You can begin with a basic memory of 256 words of static RAM memory or you can expand the Altair 8800 to 65 ,000 words of directly addressable memory. Static or dynamic or PROM or ROM memory. Or a floppy disc system . All supplied by MITS.

Thanks to buss orientation and standard interface cards provided by M/TS, the Altair 8800 requires almost no design changes to connect with most external devices. Any card can be p lugged into any slot and the correct address, etc., for that card will be picked up off the buss system . Since up to 300 peripherals can be added to the Altair 8800 without any additional buffering, the custom designer can interface to almost any number of imaginable devices simultaneously. All MITS peripherals are supplied with software handlers to make inter­ facing easy. 4 INDIVIDUAL NEEDS

MilS wants to service your in dividual computer needs. You can buy an assembled Altair 8800. Or you can start by building the computer yourself. The MITS Altair 8800 is the ultimate kit. Its assembly isn't much more difficult than assemb ling a desktop calculator. And it's made double-easy with the aid of a straight­ forward, accurate assembly manual. Or you can start with an Altair 8800 complete data processing system. Altair Systems come in 5 basic configurations. For those users who are not familiar with computers, M/TS offers free consultation service. Just describe your requirements to our engineering staff and we will specify the additional cards and the system configuration you need to do the job. The M ITS Altair 8800 is backed by complete peripheral and software development programs. -. 5 ALTAIR SYSTEMS

SYSTEM ONE Altair 81WO Computf'f 88-MCS Static Mt>rnory Card with 256 words of nwmory (expandable to 1000 words) SYSTEM FOUR Altair 8800 Computer ThreComputer Terminal

SYSTEM fiVE A It air 8800 Computer four 8H-4MCD Dynamic Memory SYSTEM THREE Cards with 16,000 words of memory Altair 8800 Computer 88-DC Disc Controller 88-4MCD Dynamic Memory Card with 4000 words of memory Two 88-DDM Dis<: Drives & Discs 88-SIOA SNial 88-SIOA Serial Input/ Output Card Input/Output Card Comter 256 Computer Terminal Comter 256 Computer TPrminal SYSTEM ONE

Sys tem One is t he A ltair 8800 Co mputer plus 256 words of static memory. That's enough memory to do many machine language procedures and some control applicatio ns . The Altair 8800 Computer includes the CPU (Centra l Process in g Unit), front pa nel contro l board, front panel lights and switches, power supply and expand(•r boa rd (with room for two ex tra card s) all enclosed in a ·handsome, aluminum case from Optima.

~ ; ... . SYSTEM TWO

Sys tem Two consists of the ba sic Altair 8800 plus enough memory to do simple machine language programming. Th e VLCT Computer Terminal converts octal input to binary format, thus making programming faster and eas ier. The Para llel 1/ 0 Ca rel contains all the required addressing circuitry to address anywhere from location 0 to location 255 .

SYSTEM THREE

Sys tem Three includes 4000 wo rd s of dynamic memory with a basic access time of 415 nanoseconds (twice 6 as fast as static memory) and a memory protect feature that prevents accidental writing into memory. Th e Seri al 1/ 0 Card is a fu ll RS232 interface card with the necessary divider logic to allow for a broad range of prese ttable ba ud rates . Th e Comter 256 Co mputer Terminal al lows you to " talk" to the computer using full Alpha-numeric format. Th e Comter 256 is a surprisi ngly versatile computer terminal. Its basic memory of 256 characters with expanclabil ity to 1024 charac ters combines with a 32 character Self-Scan display to provide ease of operation.

SYSTEM FOUR

System Fo ur has the power and memory for establishing complete accounting procedures to say nothing of its 1000's of other applications. The Audio Ca ssette Interface gives you virtually unlimited memory. 12,000 words of dynamic memo ry allows you to program in asse mbler, basic or any of the higher level programming languages.

SYSTEM FIVE

System Fi ve is one powerful configuration. Dual Disc system includes the 88-DC Disc Controller which is capable of cont ro lling over 200 flexible disc drives. Each of the disc drives included with System Five are capable of stori ng up to 262, 000 words of data. This system is for the most advanced data processing applications. THE ULTIMATE SYSTEM

The li st of option~ (either availablf' or in clevf'lopment) gof's on and on. The five Altair Systems are only the beginning. You can buy onf' of these systems and takf' advantage of the SystPms ' Discount (sep f'nclosf'd price list) or you can custom cksign a system that fits your individual needs. The Altair 8800 has very few, if any limitations. You may begin at the "low end" of the data procf'ssing scale and over the years wind up with the "ultimate" system. Using standard M/TS interface cards, the Altair 8800 can bP connected to M/ TS peripherals (computer terminals, 1/ 0 cards, aud io-cassctte interface, I i ne printers, etc.) to form the core of a sophisticatPcl tinw-share system . l he Altair 8800 can be a process controller. It can be an f'ducational device. Or, it can be expanded to be an advanced, custom intrustion system . A programmable scientific 7 calcu lator. Automatic I C tf'stcr. Automated autornobi If' test analy7er. Complete accounting system . " Smart" cornputf'r terminal. Sound and light control system. Or it can be all of thesf' things at the sarnP time. It could lw the beginning of new business opportunities. The I ist of app I ica ~ions is I iterally end l0ss .

Just think of the possibilities ...... ALTAIR 8800 I

MEMORY

Maximum of 65 K w ord s 1/ 0 MISC. PROCES SOR OPTI ONS

1000 wo rd stati c memo ry ca rd wi th 8 Bit Paral lel PROM's Vectored Interrupt 256 word s memory l/ 0 Card 8 levels

256 word memory PROM Programmer Seri al 1/ 0 Card modu les RTC Rea l Time Clock RS 23 2-TTL

4000 word dynamic Serial 1/ 0 Card PROM M emory Cards memory RS232 Floating Po int 8 Processo r"'·' Altair 8800 Cyclop's Controller 16,000 word mass Serial 1/ 0 Card memo ry·::· TTY Register Di spl ay''

A ltair 8800 Cyclops Cameras

Direct M emory Access Expander Card Contro ller

Prototype Board

Expander Chassis DMA 1/0 Channel DMA 1/ 0 Ch annel Intern al Extern al

Spec ial DMA for Electronic M em ory & Floating Po int Processor H~MINALS MASS S JUJ{AGr MAIN-II NANCr AIDS

CornptPr 2:'i6 VlCI Dis(: Controller 4 Cham1PI VNY Low Cost Storag<· Scope CompJ,JtN 1<-rminill Disc Driw ComptPr 1024 2'i(,,OOO words (up to 200 Dri ws) Low Cost U n<• [xt<•nd<'r Catr

:12 CharactC'r Alpha ll<•<:tronic Disc ControiiN* Num('ric Display 9

Card Punch* El('(·troni<· Oisr lbK to 1M<•g ~vonls/drivf' K<>yboard up to 4 Discs*

Plottt>r* Audio fapt> lnterfac<' 231-' Dis<-ControiiN*

Card ~f';=tdN* :B14 Disc• rTY* (2ma¥)

Pap<'r ·rapo Pu11eh*

Line lap<• ControiiPr Printer

4 Driv<·s

*In planning stagt>. All otlwr p<•riplwrill s lopnwnt ~tagP . POSSIBLE USER APPLICATIONS (This li st is a small % of the possibilities)

programmable scientific calculator control applications multichannel data acquisition system pumps automatic control for ham station motors sophisticated intrusion alarm system valves automatic IC tester · set points machine controller fans digital clock with all time-zone conversion solenoids high-speed 1/ 0 device for large computer stepping motors digital signal generator drive contractors automated :automobile test analyzer etc. on-board mobile controller autopilot for planes, boats, etc. navigation computer time-share computer system · 10 " smart" computer terminal brain for robot pattern-recognition device printed matter-to-Brai lie converter automatic drafting machine automatic controller for heat, air conditioning, dehumidifying controller for sound systems digital filter signal analyzer stock market analysis complete accounting system credit card sales cash sales markdowns charge sales gross profit labor costs average cash sale payroll inventory etc. the OPTIONS INTERFACE SPACE NAME& REQUIRE­ REQUIRE­ NUMBER DESCRIPTION APPLICATION MFNT MENT HH MCS Static I his Static MPrnory Card o f SystPnls that require IIOilf' on(~ slot t\lkrnory Cud rfwrnory and i-, Pxpandns for cli-,al>ling tlw ready to< omp<·nsa!P for tlu.:.· c ontrol appli< atiom. speed of tlw card . It also < ontains rnen1ory prot<'< t featurP'i. llw static nwrnory on this < ard has a rnaxi- mum acn's~ time <.!l_BS0 _ ~~><:~~! .1~ ------­ HB-MM Memory Plugs into thP BBC MCS ,'v\ernory Card adding 2S(, words l xpand static memory in Span' on a !'v\oclule rnPmmy. I hrPe modulf's car1 he addc•d to each Static a minimum IHt for dis< uunt prin•. Memory Card 8B-4MCD 4K I his Dynarni< Men1my Card < ontains ·I,OCJ(J word<; of Systems that rf'quire none one sl o t Dynamic mPnlory. Maximum a<< <''i'> tinw is -l20 nano'><'< onds. An nwdiurn to large amounts Memory Card automati< rdrPsh cy< IP i~ p<'rfornwd ev<•ry \2 c lock of nwrnory with fast pulses at '>Yilt time. If tlw < ard is addressPcl at tlw same• access limP. time that refre-,h oc < LIIS , thE-• computer i.., givPn one or two wait states dwing t<'lrPsh . OthPrwis<'. tllf' J>rocessor is unaware that relrPsh is oc curing. l ias wr itP protect capability. Variablt> addrPs'> < ir< uitry allows U'>< ' r to pro- vide a ~tarting addre<,s in rnenrnry at any Oil( ' oi If> 11 locations - 4 -~- BK,J _2 K, _IE>K , ei.S..c______. ------BH·DMAC Direct 1 his l >irect M£>nlory A< ct>s~ ControiiPr will < ontrol B Systems that require none one slot Memory Ace ess Dynamic Input/Output Cards. llw c ontroll<'r gerwrates rapid transfer of data Controller a priority for each of the B t ards ;md can gf'nerate into the CPU or out of either an interrupt or hP ..,an1pl<'d hy th<> proU''>'><>r for the CPU . Allows for job cornpiPtion. Self'< ts thP channPI to have acce-,s to simplified software. the address buss and < ontrol hu-,s when a DMA is to ocn_rr. ~equire that require B8-DMAC one slot Memory 1/ 0 Memory Access transft>rs betw<'en tlw pron'ssor and rapid transfer of data Channel for external clevi< es . With om' DMA 1/ 0 <. hannPI opPrating, between the CPU l xternal Device~ data transfer ratf' i.., WOK bytc>s pt-r '>f'C ond, whilf' tlw memory and external processor conti rHIPS to operate at approximatt' ly BO '.Yo devi< es . Al~o for slow speed. speed, high quantity tram fer. HB-DMAI Direct Allow.., for h igh speed transfer of data hli>< b vvithin tlw Data acquisition and BB-DMAC one slot M(•mory Acce~s sy-,tern\ nwrnory, without software i nterv<•ntion after logging systems. l/ 0 Channel for set up. Internal lransfer~

88-DDM Di~<. Consists of standard flt>xibiP disc drivP and the n<'cPs · Any application where BB-DC ~ i rst two Drive & sary intPrface or multiplex card.., to < omnHrrlid . I irst controllE-r. two disL driVP'> installed in tlw mw DC Disc Controller cha-,sis. Separate < hassis supplied with each two addi­ tional disc drives (including iH>wPr supply). INTERFACE SPACE NAME& REQUIRE­ REQUIR E­ NUMBER DESCRIPTION APPLICATION MENT MEN T

88-DC Disc The 88-DC Disc Co ntroller contains a basi c Altair CPU Any applicatio n w here slot o n 10" rac k Co nt roll er and special control logic and interface t o control over m ass memory is 88-EC space 200 f lex ibl e disc drives . It is des igned specifica lly t o required . control flex ible disc drives using st and ard IBM fo rm at . Eac h drive ca n contain 262 K bytes (w ord s) of sto rage o rga ni ze d on 73 tracts with 26 sectors per t ract . Con­ tro ller comes in cabinet with provisions for 2 drives. Additional drives ca n he insta lled in se parate cabinet s. 88- PROM Two bipolar 256 x 4 Shott ky PR OM's. Access time of 70 Co nt ro l applications. 88-PPC PROM kit nanoseconds. PR OM Programmer Ca rel 88-PI O Parallel Full parallel input/output ca rd w ith necessary hand­ A ny app lica ti o n w here has c.,ta nd ord one slot Input/ O utput shake f lags for conve nt io nal parallel interface . Co n­ d at Cl is ava il able in 1 TL drive's & Ca rel ta in s all req uired adclrt'ss ing c ircuitry t o allow each p Cl rallel or the ex tern al accep t ~ ca rd to be addresse d anywhere from locatio n 0 to loca­ interface requires pa rallel st andard tion 255. Go th input and output d ata has their own 8 bit d ata. TTL signals ·lat ch for buffering. Includes necessa ry logic to allow an adjace nt channel to be a contro l channel. Th us, adjace nt channPI ca n be US(:'d to set up fl ags and also clear fl ag s and interrupts. 88-S IOA Ser ial Full RS2 32 interface ca rd wit h signal compatibi lit y to lntt>rfac in g any conve n­ ConvC'n ­ o ne slo t In put/ O utpu t conve ntional RS232 interface. Uses a UART and has tional RS232 type tional RS2 32 Ca rd RS232 di vider logic to allow for presettahle baud rates from IX' rip lw r a Is ·11 0 to 19,200. Us('s adjacent channel f or contro l if des ired. If the ca rd was se lected to have an add ress of I, adjace nt 1/ 0 channel 0 would be th e contro l cc:1 rd 12 for setting up tlw r('q uired f lags. 88-5 10 8 Se ri al Sc:1 me as 88-S IOA e\Cept all signals c:1 re TT L levels (both tra n s mi s~ i o n of data w ith Standa rd Oil(' sl o l Input/ Output in c:1 nd out). se ri al format Tl L signctls Ca rd TTL 88-S IOC Se ri al Sa me as 88-S IOA except th at it is for in tC' rfac ing w ith inlerf Clcing to te letypes St <1ncla rcl one slot I nput/Outpul conve ntional te letypes . TTY signals Ca rel TT Y 88-V I Vec tored Gives US(:'r B levels of hard ware vectored interrupt. Any type of in tc' rrupt All M ITS one slot Interrupt Automat ical ly es tabl islws restart addresses for intc' rrupts. structured ~yste m . stan cl arcl Es pecia lly use fu l in rc·a l 1/ 0 chan­ tim C' applications. nels have provisions to inte rhn' Lo vectored intc'rrupt 88-RTC Rea l Provid es interrupts to t lw processor at use r se lected Any rea l time sys t C' m o r Req u i rl'S fi l s on Time Clock ra te of o ncP every 100 microsecond s, 1000 micro­ d ata logging sys tem Vectored Vc>c torecl seco nd s, '10 mi lli seco nd s o r '100 rnilli seco nds . I ntC' ri'Ll pt Interrupt ca rd . 88-ACC A ltair Digital, so lid state TV ca mera. 102 4 elements in a 32 x Co mputer with eyes such 88-CCC Ca mera is Cyc lops Ca mera 32 arra y. Eac h detector is ca pabl e of 16 gray levels and as an intrusio n syst ern, Cyc lops 2" X 3" X 8", automatic electronic stops are ad just able by the soft­ prod uctio n line cont ro l, Co ntro ller ware. Up to 16 ca meras ca n be contro lled by o n ~ auto m atic in spectio n Card Cyc lops Contro ll er. M ultiple contro llers ca n be used . stations. 88-CCC Altair Wi ll support up to ·16 ca meras simultaneously. Con­ one slot Cyclops Co n­ t ain s buffer memory and all 8 stop cont ro ls to com­ troller Ca rd municate w ith the camera. Provides all interf ac ing for Alta ir Cyc lops Ca mera. IN TE RFACE SPA('r NAME& REQUIRE­ REQUIR ~ NUMBER DESCRIPTION AP PLIC ATIO N ,\. f ;T MENT lliH;g;, Nunwri r Dbplay 111ounted in ib ow ~ ~ c, . e. A.ny application requir­ ( ) fl r> 'I 11, 1 )i t--l ll!llPric It• !t d e ~ c onlruller card . i ng llllllleric readout. f'XI t '!, Ji_ ~.play ------£,l) it l: i 1. ; >.A \low:, LISP! to ,·(JflVf'tt rrurll octal tor m at to hlflill).' and M e auton1atical ly p ro - Partic u larly usefrd in one -; lot ,. rr ')'/ dP • r g rarnn1ed into f'rogramrm1bl(• RPad Onl y M(-'rl1or ie..,. ·1fH ' control a ppl icat!Oil'> :rd J>I\Oi'v\ s TlOrtllally used in tlw A\t;-1ir BBtlO ;ue b ipol <1r ~< hottky !'ROM\ with 70 nanosPconcl <'l <" n's" tinw . t C1Ch PIH'M 1'-l orgarlil(-'d <1' c1 Fi(, X ..f fllPPlory f hu~ , two J>I,?OM\ arE-' rt-•qu irPc1 to ~ll hif' Vl' <1 :!.r;(> x B !llC'flH>IY Cr p ru~ratnrning - ·· --. -- ~--·------~ ------·· -- -- \1 c harnc lN alpha-rHifn(•ric Bur rough~ St•l! c;Cci lt cL "­ /\ny a­ pldy mountPd in its own c ·1se . lncluck•:-. CO!lttolll.' r w i th Cliphi p>v tnter fclCP logic and power supply. Oi~f.Ji c1V C. f> ·l f\'-i(. ll cahi r;<'l ( 1.1 , charact€,_ ., and hac, 32 chd mPmorv storagP f or d :1t,1 o r ( OllllE'Ct~ to C111 V Ca-,<;t• l' ~ oftwctr{' . OpPt<'ltes hy modtJI:. i r1 rnedi u m qu<1litv l(> chnrd< tPrs vvith f'\flilnclahilrty to CompulC'r LPrtlli lla l wit h (\1\ (, j( )r\ Jllf.(l I '.r· d 1024 clt < on thtr H''> w1th a 32 c h aracte1 cli..,p lny ;\lph i1 nunw r ic di <.p\c1y C.,(' I i ,11 !/ () to pmvid(' t',1~(' nt op<'rCltioll . Spt•c 12d furH tiun kE'Y'> lor d<1La retriev<1\ i111d clisplocml 13 i11ld 110noo baud rat( ' ~- Auto trar1snrit <1nd luss to !)(' extPnded out of the d evelopment or care\ ra< k to r C'Cl )' mainte11ancP. mainte nancP i s antic ipatf'd ------·· ------~- -- ;\ wide ZJ~s() r trrwt:t of CZJSc~ is avad c1 h iP for adding P:\tf'r nal cl<•vic f' ~

f' ower supply, Optima cahi•H' t and four l.xp;mdt>r Cctrds l xpanded ~y~lP r1l One slot B' ' rack ;r\lows for i.llt expansilm o f ·If> c,mls to the Alta ir 8:-100 . in bP

MOVr1·r2 Move register to register 0 D 0 0 s s MDV M, r Move register to memory 0 1 1 0 s s MOVr, M Move memory to register 0 D D D 1 HLT Halt 0 1 1 1 0 1 MVI r Move immediate register 0 0 D D D 1 7 MVIM Move immed iate memory 0 0 1 1 0 1 10 INR r Increment register 0 0 D D [) 0 0 5 INSTRUCTION OCR r De crernent register 0 0 D 0 [) 0 1 5 INR M In cre rnen t memory 0 0 1 0 0 0 10 OCR M Decrement memory 0 0 0 0 10 ADDr Add register to A 0 s 4 SET AOC r Add register to A with carry 0 s r' SUB r Subtract regi ster from A 0 s SBB r Subtract register from A 0 s with borrow ANA r And register with A s Summary of XRA r Exclusive Or reg ister with A s 4 ORA r Or register with A 4 CMPr Compa re register with A ADD M Add memory to A ADC M Add memory to A with carry Processor SUB M Subtract memory from A SBB M Subtract memory from A with borrow Instructions ANA M And memory with A 0 0 0 XRA M Exclusi ve 0 r memory with A 0 0 0 ORA M Or memory with A 0 0 CMP M Compare memory with A 0 0 ADI Add immediate to A ACI Add immediate to A with carry SUI Subtract immed iate from A 15 SBI Subtract imm ediate from A with borrow ANI And immediate with A XRI Exclusive Or immediate with A ORI Or immed iate with A 1 1 CPI Compare immed iate with A 1 1 7 RLC Rotate A left 0 0 4 RRC Rotate A right 0 0 4 RAL Rotate A left through carry 0 0 4 RAR Rotate A right through 0 0 carry JMP Jump unconditional 10 JC Jump on carry 0 10 JNC Jump on no carry 0 0 10 JZ Jump on zero 0 0 10 JNZ Jump on no zero 0 0 10 JP Jump on positive 0 10 JM Jump on minus 1 0 10 JPE Jump on parity even 0 0 10 JPO Jump on parity odd 0 0 10 CALL Call unconditional 0 1 17 cc Call on carry 0 11 / 17 CNC Call on no carry 0 11/17 cz Call on zero 1 0 11 / 17 CNZ Call on no zero 0 0 11/17 CP Cal l on positive 1 0 0 11/17 CM Call on minus 1 1 0 11/17 CPE Call on parity even 0 0 11/17 CPO Call on parity odd 0 0 11-/17 RET Return 0 1 10 RC Return on carry 0 0 5/11 RNC Return on no carry 0 0 5/11 Instruction Code [1] Clock[2J Mnemonic Description ~ Os Ds 04 03 02 o, Do Cycles

RZ Return on zero "1 0 0 0 5/11 RNZ Return on no zero 0 0 0 0 5/11 RP Return on positive 0 0 0 0 5/1 1 RM Return on minus 0 0 0 5/11 RPE Return on parity eve n 1 0 0 0 5/ 11 RPO Return on parity odd 1 0 0 0 0 5/ 11 RST Restart A A A 1 11 IN Input 0 1 0 10 OUT Output 0 0 10 LXI 8 Load immediate reg ister 0 0 10 Pair 8 & C LX I D Load immediate register 10 Pair D & E LXI H Load immediate re gi ster 10 Pair H & L LX I SP Load immed iate stack poi nter 0 0 10 PU SH 8 Push registe r Pair 8 & C on 0 11 stack PUSH 0 Push register Pair D & Eo n 11 stack PUSH H Push re gi ster Pai r H & Lon 11 stack PUSH PSW Pu sh A and Flags 11 on stack POP 8 Pop register pair B & C off 10 stack POP 0 Pep re gister pa ir 0 & E off 10 sta ck . OP H Pop register pa ir H & L off 10 stack POP PSW Pop A and Flags 0 10 16 oft stack STA Store A direct 0 13 LOA Lo ad A dire ct 0 13 XCHG ExchangeD & E, H & L 0 4 Reg isters XTHL Excha nge to p of stack, H & L 18 SPHL H & L to stack pointer 0 5 PCHL H & L to prog ram counter 1 0 5 DAD 8 Add B & C to H & L 0 0 0 10 DAD 0 Add D & E to H & L 0 0 0 10 DAD H Add H & L to H & L 0 0 0 10 DAD SP Add stack po int er to H & L 0 0 0 0 1 10 STAX B Store A in direct 0 0 0 1 0 STAX 0 Store A ind ire ct 0 0 0 0 lDAX 8 Load A ind irect 0 0 0 0 LDAX D Load A indirect 0 0 0 0 IN X B Increment B & C reg isters 0 0 0 I ' X D Increment D & E registe rs 0 0 0 INX H Inc rement H & L registers 0 0 0 INX SP Increment stack pointer 0 0 0 DCX 8 Decrement B & C 0 0 0 DCX D Decre men t D & E 0 0 0 DCX H De crement H & L 0 0 0 DCX SP Decre me nt stack poi nter 0 0 0 NOTES: 1. DDS or SSS- 000 8 - 001 C- 010 CMA Comp lim ent A 0 0 1 4 D - 011 E - 100 H - 101 L - 110 Memory - 111 A. ST C Se t ca rry 0 0 1 1 1 4 CMC Compliment carry 0 0 1 1 1 4 2. Two possible cycle times, (5/11) in.dicate instruction DAA Decimal adjust A 0 0 0 1 1 4 SHLD Store H & L direct 0 0 0 0 0 16 cycles dependent on condition flags. LHLD Load H & L di rect 0 0 0 1 0 0 16 El En ab le In terrupts , , 1 1 0 4 Dl Disa ble interrupt , 1 1 0 0 4 NOP No-operation 0 0 0 0 0 4 QUESTIONS AND ANSWERS

Alread y we have received lOO's of ques­ tiH' 8/iO(! is tlw Intel lHWO pl o<<'~'>o l O n <' rn ay p rove• to hP ad Pq uat<'. M o st .· tions from our cu stomers about the c hip. fhi s o ne int t->g 1atpd < irt ui t con control ap pl 1< atiom ~ho uldn ' t tak c> Altair 8800 Computer, Altair Systems t a in~ i ng unit. lll<' lllory. If you u sc• yolll Altait 8800 for is des igned to answer most of the <:om­ n1 o 1<' '>o phisti< atPd Cl< < o unting and mon questions. If you have any addi­ M /TS was o ne o i til<" f i rs t colllpanies Pngi n C'<' I ing appli< at ion s, you wi ll of tional ques tions, comments or thoughts to m onu facture high volurnc• , low cost coUI '>(' rH 't'd Cl larger ltH' Illory. l h C' related to th e Altair 8800, please feel ca l c ul a t o r ~ . O ur f'XJWI ie ncc• with large nwnH>J Y in tlww Clp pli c'i ,OOO vvorcb. But, in tlw p rodu< t ion faci lit ies h a~ enabled u s to ca-,e of a u~<'r w lr o do<''> a lor gc• Cl nlo u n t //ow poi\'C'I iu l is thP A ltai! lWOO ancl b uild a computer at a very lowe ost. o t so f twilr<' d c'v<'lo pnwnt in n1 ac hirw or ho\\' cf~<' l n h ly languag<', 1\,000 word s sho uld puter\1 fluw does t he q uality oi the A ltait ll800 b<' ad (•q u . Co mputer < u m pare with othf'r com ­ r IH· l <'r nl " powe'r" in a ( ornpu tc• r i'> putAh( Aga in, if you have any qupstions con­ rPiatPd to a numlwr of diil t>rc•nt it('rll '> < ern i11g Cl particu lar ap pl ic Cit ion, f(•e l and it !Pnd., to IH' a nc· l> u lou-. n H'a'>ur<'­ W c,'d li"e to t hat t iH' lo w< ost of ~ tr <">s free to c o nta< t M lf!-l fm dPaii C' d inf or­ nJ e nt In clll)! < CIW , t lw rn o'>! c•a<; ily tlw A lta it 8800 was not c iiic <; LJ ggP~ ti ons idPntJiial> lc· JH'rforma rH <' c rit<'r i a < O r llJ)I O illi ~ in g t iw SJH'<' cl , llH'nlOI\' site' t lw A ltair fWOO is as good CIS to th<' A ltait llHOO Conlptt ter( 17 ~< '< one! <;; it c an din·< tly bS ,OOO f10 11 t p anc' i ind ie ator lam ps. In n 1ost wor d <; (H l> it l>yt<'~ ) ; one! it carl con n c•e t cornputHs, these la mps ar<' inc a n dc'~ rl w A /t ail lWOO ho<> l>c'c> n d c•signPd w ith to 2'lb inpt rt a nd 2'>(> output c!P\ i< P~ Its < e•n t bulb'> whit h burn o ut frl'q ue n t ly. a b u ss sy'>t<'l ll t h c1 t allows for re lati v<' ly cyc l<' tirn<' i !> c o rn poral>lt> to rnost sm oll ·11w A ltair 8/WO usps I LD \ w h ich h aw si m p le in t<' rfc ­ < <>lllJH i t<· r., on the • lll CI I ~ Pt tod tly (tlwv an c t JO ni< sengi­ ra n g<' fl()rll .B mit r o~<'CO I H I S to SC'Vl'ICI I ~wi t c lw s arc> high qual ity, rn ini i te' and toggl<' switc h('s i lity, t iH' A ltair tW OO lw Jh tlw switdws and low t o'> t ro cker '> Wi tdH•s abl <' to inte rf! m ini 's. Mo~t Sin al I com l <' o n !><> nw p 1oc e~sors . f h<' ci r · <'Xt <'r n CI I "Y~ t Pms in a rninimum amount put<>r s c ar1 dirt>ct lv odclrC'ss (>·l 01 fc•w<' l < u it llo mds arE' nil f ih<'lglass pl atc•d of t im<'. Con -. ulting tinw for c u <> to m input/output c ha nrwl., CIIHI onlv "i 12 board s a nd e'at h card i n t lw Altair Sr~ ­ projN h is avai labiP from M /7 .\ QuP'>­ words of nwrnory. An in cl ll <'<'l conn<'< ­ te /ll h as it s o w n powe'r regu lntor. IIH' t ions cont<'rning spe< iiic d c•s ign pi(Jb­ t 1on to os<' pagP i<; u<.un ll\' rNr u ired C igg<' l n H'IlHll ie'i . a lu minum < o n sliUl lion corn plc't<' w rth <,u b c h assi'> and a ialsc> fmnt pilrwl. I am not iat niliat 1\'ith l>a'>ic computer li til <> Altair lWOO ha\ '>liCh g1c>at \f!<'< iii­ technolog\ , i> ut I do have a h a~ic uncf<'r · ca tio ns, 1vh v i., it ~ o inc•xperL'> iVC'; / /ow /arg<' a llH'moty ~ h ouhl I uf(l<'t standing of e/C'c tronics . //mv long \\'ill 1\ ith Ill}' A lta it IWOO C otllJ)(tt<'tl it ta!-..P llH' to f> pconH' ia tniliar enough l 11 d C' w lopirlg tiH' ;\/tait lWOO. f\1 11 <., l"> 'ith the A ltair 8800 in m cl<' r to in t<' r Pngin<' PI s rnack < ' '\tt ' n~ivl' us< ' o f larg<' In gE' IH'r a l, th is is a di ffi< u lt tion facf' it in to a r u ~ to n1 .,ys tpm( ~(alP inte•grCitPd C irtuit \ ('( hno lo gy. [ h i~ t o on'>we•r. If you pl an on u sing your is tlw sa m <' lt'< h nologv thnt br o ught A /tall Sys t<'fll f o r r P i c~ ti vPiy c;,i n lpi<' con­ r his t oo, is a difficu l t CJ UPStio n . Tl w dowr1 t lw price of r, l Pchnician, st ate i n our ad litPratur<', t iH' !><'< r< ' t of stntic nw mory p rovid<>d w ith <.,} ~tem or hobbyist sho uld bP ahl <' t o writ<' si mp le m ac hine prog ramming in a want to des ign an electro ni c interface '1 -2 t ho usa nd doll ar range, thC'Il com­ m attC'r of a few ho urs after first being for so me type o f unique electro nic puter cont ro l becomes c1 vc' rv intPrest­ ex posed t o the Altair. Th e am ount of device or electro-mechanica l devi ce. If ing app licati o n. The controller tc'r m is t ime after that to actually generate an desired, MITS will pro vide required used freq uently w it h small processors operating program, of course, will enginee ring o r software suppo rt f or any b eca u se th e im p l icat i ons arP over­ depend o n how complex and how large project at a nominal cost . w helming. the p rogram is and will also be related to the creativity of the individual do ing Th e literature I have read concerning Wh at are th e busine s opf)ortunitics the p rogran1ming. mall pr ocessors contain s a large fo r someone ~vho would lil,e to desig n custom systems using the Altair 8800( amount of in formati on on using th e A n yo ne w it h a b as i c am o unt o f c ompute r as a control d evice fo r assembly language o r m ac hine lan­ Th ere are li terally t ho usa nds of custo m external electo-mechanica l sy ~t Nn s . guage programming experi ence sho uld Does this mea n th at small computers applicatio ns t hat requi re or could use be able to write program s for the com­ are in ca pable o f do in g b usin ess, a computer. We st ro ngly encouragP puter almos t instantly. accounting, and engin eerin g cal cula ­ anyone inter('Sted in t h is sort of husi­ tions? nPss o pportunity to look 1nlo it i11 sonw depth . I ha\'e clone a comicle rable amount of Absolutely not . The m ain reason that computer progra mming, but I kn ovv small processo rs are c losely associated alm ost nothing about electronics. How with controlle rs is th at the cost o f the long will it take me to lea rn enough processo r is low eno ugh that it can be 18 electronics to c/o m y jab? used as a system controlle r. Fo r exa mple. if yo u wanted to contro l a lathe with a If Alta ir 8800 st andard interfaces are computer, it's clear that a 3 millio n "[realM! Ele,troni[s" use d , no knowled ge of e lectro nics is do llar computer install ati o n wouldn't req uired in o rder to use the Altair 8800. be a very good w ay to go. But, if we arc This statement doesn't apply if you talking abo ut a computer sys tem in the

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