COMPUTER CLUB NEWSLETTER HOMEBREW

(1)

HOMEBREW NEWSLETTER

COMPUTER CLUB

^{, ,}

Robert R e i l i n q , e d i t o r

0

P o s t O f f i c e Box 626 Mountain View, CA 94042

Volume Number 2, I s s u e 1 J a n u a r y 31, 1976

THIS MONTH - Robert R e i l i n g

A LETTER FROM MITS - J u s t a s t h e N e w s l e t t e r was i n f i n a l p r e p a r a t i o n a l e t t e r a r r i v e d from B i l l Gates v i a MITS. Reproduced ( t h e o n l y MITS

" s o f t w a r e " we have e v e r r e p r o d u c e d ) on page 2 , it should be r e a d by

e v e r y computer h o b b y i s t . S u r e l y many of you w i l l want t o w r i t e t o B i l l . Send a copy of your correspondence t o m e a t t h e HOMEBREW COMPUTER CLUB NEWSLETTER, P.

0 .

Box 626, Mountain View,

CA

94042 and I w i l l t r y t o summarize your comments.

CASSETTE UPDATE - Harold Mauch of Custom Design S e r v i c e s w r o t e P e t e C o r n e l l s e n d i n g t h e l a t e s t c i r c u i t l a y o u t developed f o r t h e t a p e

s t a n d a r d adopted a t t h e BYTE Symposium. I t ' s a l l on page 4 and 5 i f , a s Harold s t a t e s , you would l i k e t o "brew your own".

T I N Y BASIC - PCC's f i r s t i s s u e of t h e Tiny BASIC n e w s l e t t e r i s ready.

Volume 1, Number 1 h a s 1 9 pages f u l l o f i n f o r m a t i o n you c a n u s e . Pages 2 t h r o u g h 12 have r e p r i n t s of t h e i m p o r t a n t P e o p l e ' s Computer Company a r t i c l e s on Tiny BASIC. Now you can "home brew" your own BASIC; it w i l l t a k e t i m e b u t it w i l l be your p e r s o n a l B A S I C when it i s done. The n e w s l e t t e r i s $3.00 f o r t h e f i r s t t h r e e i s s u e s . W r i t e PCC, Box 310, Menlo Park, CA 94025.

MEETING FACILITIES - P l e a s e r e a d t h e p o l i c y of SLAC r e g a r d i n g u s e of t h e i r f a c i l i t i e s . I t ' s on page 3 and i m p o r t a n t .

SOFTWARE - Tom P i t t m a n h e l p s u s a g a i n w i t h s o f t w a r e i n f o r m a t i o n . Check t h e DATA FILE, page 7 . I would l i k e t o i n c r e a s e s o f t w a r e m a t e r i a l i n t h e N e w s l e t t e r and r e a l l y need some c o n t r i b u t i o n s . Send your i d e a s .

. . .

PROBLEMS

VDM-1 - Many people a r e w a i t i n g d e l i v e r y of t h e VDM-1 Video Display Module from

P r o c e s s o r Technology C o r p o r a t i o n , having p l a c e d t h e i r o r d e r some time ago. O r i g i n a l l y a v a i l a b i l i t y was s e t f o r December 17, 1975. D e l i v e r y was t h e n scheduled f o r J a n u a r y 15, 1976 and customers with pending o r d e r s were n o t i f i e d . A s of t h e end of January, d e l i v e r i e s had n o t been completed. How does t h i s happen? I t t u r n s o u t t h a t t h e c h a r a c t e r g e n e r a t o r needed i s i n v e r y l i m i t e d supply and PTC i s a w a i t i n g d e l i v e r y of t h e s e p a r t s . It would appear t h a t p a t i e n c e i s a n e c e s s a r y a t t r i b u t e of t h e computer h o b b y i s t .

ALTAIR 680 - MITS has decided t o i n m e d i a t e l y upgrade t h e A l t a i r 680 t o i t s second

g e n e r a t i o n design. The new d e s i g n w i l l i n c l u d e a d d i t i o n a l f e a t u r e s a t no a d d i t i o n a l

c o s t . D e l i v e r y d a t e s , according t o MITS, w i l l b e s e t back by 30-60 days. I f you

have experienced d i f f i c u l t i e s w i t h a f i r s t g e n e r a t i o n u n i t , you may want t o c o n t a c t

MITS and d i s c u s s t h e p o s s i b i l i t y of exchanging i t f o r a second g e n e r a t i o n design.

(2)

F e b r u a r y 3 , 1976

An

Open L e t t e r t o H o b b y i s t s

To me, t h e m o s t c r i t i c a l t h i n g i n t h e hobby market r i g h t now i s t h e l a c k o f good s o f t w a r e c o u r s e s , books and s o f t w a r e i t s e l f . Without good s o f t w a r e and an owner who u n d e r s t a n d s programming, a hobby computer i s wasted.

W i l l

q u a l i t y s o f t w a r e b e w r i t t e n f o r t h e hobby m a r k e t ?

Almost a y e a r ago, P a u l A l l e n and m y s e l f , e x p e c t i n g t h e hobby m a r k e t t o expand, h i r e d Monte Davidoff and developed A l k a i r BASIC.

Though t h e i n i t i a l work took o n l y two months, t h e t h r e e of u s have s p e n t most o f t h e l a s t y e a r documenting, improving and a d d i n g f e a - t u r e s t o BASIC. Now we have 4K, 8K,

EXTENDED, R 3 M

and DISK BASIC.

The v a l u e o f t h e computer time w e have used exceeds $40,000.

The f e e d b a c k we have g o t t e n from t h e hundreds of p e o p l e who s a y t h e y a r e u s i n g BASIC has a l l been p o s i t i v e . Wo s u r p r i s i n g t h i n g s a r e a p p a r e n t , however. 1) Most of t h e s e " u s e r s " never bought BASIC ( l e s s t h a n 10% of a l l Altair

2::.r,zzs have

bought

SkSIC), a113

2 ) The amount o f r o y a l t i e s we have r e c e i v e d from s a l e s t o h o b b y i s t s makes t h e t i m e s p e n t of A l t a i r BASIC w o r t h l e s s t h a n $ 2 a n hour.

Why i s t h i s ?

A s

t h e m a j o r i t y o f h o b b y i s t s must b e aware, most o f you s t e a l y o u r s o f t w a r e . Hardware must b e p a i d f o r , b u t s o f t - w a r e i s something t o s h a r e . Who c a r e s i f t h e people who worked on

it g e t p a i d ?

Is

t h i s f a i r ? One t h i n g you d o n ' t do by s t e a l i n g s o f t w a r e i s g e t back a t MITS f o r some problem you may have had. MITS d o e s n ' t make money s e l l i n g s o f t w a r e . T h e - r o y a l t y p a i d t o us, t h e manual, t h e t a p e and t h e o v e r h e a d make i t a break-even o p e r a t i o n . One t h i n g you do do

i s

p r e v e n t good s o f t w a r e from b e i n g w r i t t e n . Who c a n a•’-

f o r d t o do p r o f e s s i o n a l work f o r n o t h i n g ? What h o b b y i s t c a n p u t 3-man y e a r s i n t o programming, f i n d i n g a l l bugs, documenting h i s pro- d u c t and d i s t r i b u t e f o r f r e e ? The f a c t

i s ,

no one b e s i d e s u s h a s i n v e s t e d a l o t o f money i n hobby s o f t w a r e . We have w r i t t e n 6800 BASIC, and a r e w r L t i n g 8080 APL

and 6800 APL,

b u t t h e r e i s v e r y lit- t l e i n c e n t i v e t o make t h i s s o f t w a r e a v a i l a b l e t o h o b b y i s t s . Most d i r e c t l y , t h e t h i n g you do i s t h e f t .

What a b o u t t h e guys who re-sell A l t a i r BASIC, a r e n ' t t h e y mak- i n g money on hobby s o f t w a r e ? Y e s , b u t t h o s e w h o have been r e p o r t e d

t o u s may l o s e i n t h e end. They a r e t h e ones who g i v e h o b b y i s t s a bad name, and should be k i c k e d o u t o f any c l u b m e e t i n g t h e y

show u p

a t .

I

would a p p r e c i a t e l e t t e r s from any one who wants t o pay up, o r h a s a s u g g e s t i o n o r comment. J u s t w r i t e me a t 1180 Alvarado SE, g114, Albuquerque, New Mexico, 87108. Nothing would p l e a s e me more t h a n b e i n g a b l e t o h i r e t e n programmers and d e l u g e t h e hobby m a r k e t w i t h good s o f t w a r e .

B i l l

G a t e s

G e n e r a l P a r t n e r , Micro-Soft

(3)

JANUARY MEETINGS

January 7, 1976

-

The f i r s t meeting of 1976 was a t t e n d e d by a s t a g g e r i n g number of computer hobbyists. A t l e a s t 300 were on hand. A survey of t h i s group r e v e a l e d t h a t many systems a r e up and running. D i s t r i b u t i o n

is:

A l t a i r 8800 s y s t e m

-

28; A l t a i r 680 systems

-

one; 6800 systems

-

e i g h t ; 650X systems

-

seven; 8008 systems 1 seven;

4004 systems

-

one; miscellaneous systenls

--

n i n e ; and n i n e non-Altair 8080 systems.

The group a l s o has 28 computers under c o n s t r u c t i o n .

The formation of a n o n - p r o f i t c l u b o r g a n i z a t i o n was suggested by some c l u b members.

A committee was formed and a d a t e set: t o look i n t o t h i s i n more d e t a i l ( A c h a r t e r h a s been w r i t t e n by t h i s group and i s reproduced on page 6).

Bob Marsh of P r o c e s s o r Technology Company generously .presented t h e Club w i t h boards complete with 1702A1s ready f o r u s e w i t h an A l t a i r . The boards were promptly r a f f l e d o f f t o an e n t h u s i a s t i c group w i t h proceeds going t o t h e Club t r e a s u r y .

J a n u a r y 21, 1976

-

Another w e l l a t t e n d e d meeting f i l l i n g t h e SLAC auditorium. The

" C h a r t e r Conimittee" gave a rundown on t h e proposed c h a r t e r which was followed by a l i v e l y d i s c u s s i o n of p r o s and cons. A v o t e on adoption w i l l be h e l d a t a f u t u r e meeting.

As i s usual a t t h e meetings those i n a t t e n d a n c e exchanged i d e a s , product information, and suggestions.

FEETIKG FACILITIES

S e l l i n g i s p r o h i b i t e d a t SLAC. For t h e p a s t t e n months o r s o , t h e c l u b has been meet- i n n a t Stanford Linear A c c e l e r a t o r Center.

-

Uuring t h a t time, t h e meetings have i n - c r e a s e d i n s i z e from about t h i r t y members t o o v e r - t h r e e hundred. ~ e c e n t l ~ t h e D i r e c t o r o f SLAC has reviewed t h e c l u b meetings and was p l e a s e d t o n o t e t h a t , s o f a r , no com- p l a i n t s o r problems have been reported. It i s t h e p o l i c y of SLAC management t o t r y t o a l l o w o r g a n i z a t i o n s , of which some SLAC employees a r e members, t o u s e SLAC meeting f a c i l i t i e s , provided t h e s e f a c i l i t i e s a r e n o t needed a t t h e time f o r any o f f i c i a l SLAC b u s i n e s s and provided t h e r e i s no c o s t t o SLAC i n such use.

However, SLAC p o l i c y does f o r b i d a l l types of commercial t r a n s a c t i o n s n o t conducted by o r f o r S t a n f o r d U n i v e r s i t y . P r o h i b i t e d t r a n s a c t i o n s i n c l u d e s a l e of merchandise, a c c e p t i n g of o r d e r s , t a k i n g payments, o r making d e l i v e r i e s . A d v e r t i s i n g , product d i s p l a y s , d i s t r i b u t i n g l i t e r a t u r e , making product announcements, o r p a s s i n g o u t o r d e r i n g information may b e allowed t o t a k e p l a c e during such meetings a s long a s no a c t u a l t r a n s a c t i o n s occur. Persons who d i s t r i b u t e l i t e r a t u r e a r e r e q u e s t e d t o remove unused items when they l e a v e . Parking a r e a s should n o t be used f o r any b u s i n e s s

a c t i v i t i e s whatever. Questions regarding t h e u s e of SLAC f a c i l i t i e s should b e d i r e c t e d t o M r . Douglas Dupen, SLAC,Public Information O f f i c e , phone 854-3300, e x t e n s i o n 2204.

MEETING SCHEDULE

Meetings a r e h e l d every two weeks; February 1 8 t h , March 3 r d , March 1 7 t h , e t c . Location of t h e meetings i s S t a n f o r d Linear A c c e l e r a t o r Center, Menlo Park, C a l i f o r n i a . Meetings b e g i n a t 7: 00 p.m. Ask t h e guard a t t h e g a t e f o r d i r e c t i o n s t o t h e meeting room.

CORRECTION - The Intelligent Display For Microcomputers

_- _-

diagram published in the Decem-

ber Newsletter needs two changes

as shown in the partial diagram

at the right. Line A and line D

connections to U9 were reversed.

(4)

CUSTOM DESIGN SERVICES

m N I 0COKSLtLTANTS 4091 WIWDSOR

-

OARLAND. IsU8 7504s

-

a7a.mea

December

24, 1975

Dear M r . C o r n e l l :

I was somewhat s u r p r i s e d t o s e e a r e p r i n t of my

BYTE

Symposium p r o p o s a l i n t h e Homebrew Computer Club News- l e t t e r . h e c i r c u i t shown h a s a few e r r o r s (my f a u l t ) . A c t u a l l y t h e c i r c u i t you p r i n t e d was from a s e c t i o n of o u r breadboard we used t o e v a l u a t e t h e f e a s i b i l i t y of u s i n g t h e a u d i o c a s s e t t e t a p e u n i t s . I t was n o t optim- i z e d n o r analyzed f o r parameter v a r i a t i o n , Consequently

I

do n o t know what s u c c e s s o t h e r s w i l l have d u p l i c a t i n g t h e c i r c u i t . A s

I

s a y , i t s purpose was f o r breadboard e v a l u a t i o n . We have s i n c e r e f ined t h e c i r c u i t and i n t e n d t o begin manufacturing a n assembled and t e s t e d module i i d G h i I . Z X ~ U C K R C ~ s i n g i e u n i t p r i c e w i l l be between $50 and

$60.

I

am i n c l u d i n g a copy of t h e schematic o f o u r l a t e s t c o n f i g u r a t i o n f o r t h o s e of your r e a d e r s who may wish t o

"brew t h e i r ownn. Admittedly t h e c i r c u i t i s more complex t h a n t h e minhum p o s s i b l e c o n f i g u r a t i o n .

I

f e e l t h a t s i m p l i e r c o n f i g u r a t i o n s rnersly t r a n s f e r t h e complexity t o t h e s o f t w a r e and t e n d s t o i n h i b i t many would be u s e r s . A c t u a l l y t h e c i r c u i t may be implemented t o n e a r l y any

l e v e l o f f u n c t i o n shown w i t h compensating complexity i n t h e s o f t w a r e and

I

would encourage t h o s e s o i n c l i n e d t o do so. The e n c l o s e d d r a f t a r t i c l e p r o v i d e s some r e c o m e n d - d a t i o n s and d e s c r i p t i o n of c i r c u i t o p e r a t i o n .

Why CMOS? Ths c i r c u i t could j u s t a s w e l l have been implemented w i t h TTL. A number of t h e o t h e r p r o d u c t s manufactured by P r o n e t i c s Corp. w i t h which

I

am a s s o c i a t e d a r e implemented w i t h CMOS hence t h e p r e f e r e n c e .

I w i l l

be happy t o answer q u e s t i o n s your r e a d e r s may have i f t h e y w i l l i n c l u d e a s e l f addressed stamped envelope.

s i n c e r e l y ,

Harold A. Hauch \

(5)

(6)

(7)

MOTOROLA STANDARD HEX TAPE FORMAT

-

P i t t m a n

A s more of t h e c l u b members a r e a c q u i r i n g 68QQ-based systems, we a r e g e t t i n g programs i n t h e Motorola s t a n d a r d hex t a p e format which i s s u p p o r t e d by MIKBUG. MIKBUG i s a mediocre monitor ROM which t u r n s up i n a s u r p r i s i n g number of systems. The hex t a p e

f o r m a t i s a l s o s u p p o r t e d by A M I , s o a d e s c r i p t i o n o f t h i s format may b e u s e f u l t o many o f t h e c l u b members.

The format d e f i n e s a r e c o r d e d b l o c k of ASCII c h a r a c t e r s , t h e

f i r s t of which i s t h e ( c a p i t a l ) l e t t e r "St, t h e n one of t h e d i g i t s ,

0,

1, o r 9, followed by t h e remainder of t h e b l o c k i n p a i r s of hexadecimal d i g i t s (0-9, A-F)

,

w i t h each p a i r d e f i n i n g one b i n a r y b y t e .

The f i r s t d i g i t a f t e r t h e "S" s i g n i f i e s t h e t y p e o f record:

0

h e a d e r r e c o r d . T h i s may b e i g n o r e d , a s it c o n t a i n s no u s e f u l i n f o r m a t i o n .

1 Data r e c o r d . T h i s c o n t a i n s t h e load d a t a and a d d r e s s e s t h a t

.

you a r e i n t e r e s t e d i n .

: .

@,

9 End of f i l e record.

S1 NNAAAADDDDD

. .

^DDCC

f i n e t h e d a t a r e c o r d , "NN" s p e c i f y t h e number of e s ( = d i g i t p a i r s ) i n t h e r e c o r d a s a hexadecimal

I' i s t h e hexadecimal s t a r t i n g a d d r e s s f o r t h i s b l o c k , hexadecimal datum, and "CC" i s t h e checksum of a l l p r e c e d i y b y t e s ( e x c e p t t h e "Sl"), i n c l u d i n g b y t e c o u n t , a d d r e s s , and d a t a . The checksum i s t h e b i n a r y sum ( s i t h o u t c a r r y ) of b y t e s i n t h e r e c o r d , complemented, s o t h a t t h e sum o f t h e r e c o r d , i n - c l u d i n g t h e checksum, i s 255 o r FF i n hexadecimal.

Example:

The f i r s t r e c o r d i s a h e a d e r , w i t h e l e v e n (hex PB) b y t e s a f t e r t h e c o u n t , an a d d r e s s of

fi000,

what appears t o b e t h e hexadecimal r e p r e s e n t a t i o n of t h e ASCII t e x t "Y EDT1.2" ( p o s s i b l y t h e program name), followed by a checksum @E.

The second r e c o r d i s a b l o c k o f ' d a t a , n i n e t e e n b y t e s (hex 1 3 ) , of which s i x t e e n a r e a c t u a l d a t a . The s t a r t i n g a d d r e s s i s hex

0100,

and t h e f i r s t b y t e , s t o r e d i n t h a t a d d r e s s , i s 7E ( t h e opcode of a JMP e x t e n d e d ) ; l o c a t i o n s

g l 0 l

and @I02 r e c e i v e t h e operand a d d r e s s f o r t h a t i n s t r u c t i o n , 08 and Fe r e s p e c t i v e l y . And s o on. The t h i r d r e c o r d i s t h e end of f i l e , w i t h t h r e e b y t e s , an a d d r e s s of z e r o , and a checksum of FC ( n o t e t h a t 03

+ ⁰⁰

^1-

⁰⁰ +

^FC ⁼^FF).

HOMEB BREW COMPUTER

CLUB

NEWSLETTER

(8)

BULLETIN BOARD

MODEL 15 TELETYPE - In working condition, $50/offer. Solid State Music prototyping I/O board with regulator and some parts $18 (new). Tom Schmidt 964 9437.

WORLD ALTAIR CONVENTION - A tour plan has been arranged departing from Los Angeles for Albuquerque March 26, 1976 at 4r45 p.m. and returning March 28, 1976 at 6r20 p.m. Cost $128.28 person double occupancy or

$144.23 per person single occupancy. Contact Majestic Travel Inc., 8601 Wilshire Blvd., Suite 503, Beverly Hills, CA 90211, telephone (213) 657-0441 or (213) 655-0810. Ask for Leda.

KSR 33 TELETYPES - Prices start at $600 for a rebuilt, as new, KSR 33.

HOMEBREW COMPUTER CLUB members are offered 10 to 15% (depending on item) off if they identify themselves. contact Mr. B. J. Worley, Data Terminals And Communications, 1190 Dell Ave., Campbell, CA 95008, telephone (408)