NEWSLETTER Computer Club Robert Reiling, Editor - Post Office Box 636, Mountain View, CA 94042 - Joel Miller, Staff Writer Typesetting, graphics and editorial services donated by LAUREL PUBLICATIONS, 1 7235 Laurel Rd., Los Gatos, CA 95030 (408) 353-3609 staff reporter of The Wall Street Journal, Computing. Microtrek, the computer random data ' makes this observation: "The home- magazine for the hobbyist, was first pub- lished in August of 1976. Its second by robert reiling computer industry is so new and so frag- mented that it hasn't got around to com- edition was. recently published in Personal and home computing continue puting its own progress, so nobody knows December of 1976. Subscribers to Micro- to interest more and more people. The how many individuals have bought com- trek Magazine will begin receiving Personal hobbyist clubs are expanding, more com- puters. But estimates range from 20,000 Computing Magazine with the upcoming puter stores are opening, new products to 100,000." There is much more in this March-April edition. are being announced, magazines devoted article including some quotations from Apple Computer, Inc., 770 Welch Road, to personal computers are increasing in Jim Warren, a member of the Homebrew Palo Alto, CA 94304, telephone (415) number, and predictions are being made Computer Club and editor of Dr. Dobbs 326-4248, has advance order information about where we are going. A few people Journal. Look this article up if you for the Apple-11. The Apple-I1 consists of are attempting to determine what has hap- missed it. a 6502 microprocessor, video display pened in the past two years and how I note that De Anza College is offering electronics including color graphics, RAM, many computers and computer people microcomputer programming courses. ROM, ASCII keyboard port etc. all on a are out there. Contact DE ANZA COLLEGE - SHORT single PC board. If you order now, delivery This issue of the NEWSLETTER has a COURSES, 21250 Stevens Creek Roule- is expected to be no later than April 30, survey that presents a list of the Home- vard, Cupertino, CA 95014. 1977. brew Computer Club systems. I even pro- David Bunnell, publisher of Personal Don't forget articles are needed for the jected that data. Maybe you would like Computing Magazine, has announced the NEWSLETTER. Also, don't forget your some facts about the Homebrew Computer acquisition of Microtrek Magazine which donations are needed to pay for postage, Club, not projections just facts. OK, from will become a special section in Personal printing, etc. the history file: Homebrew Computer Club first meeting- March 5, 1975 First meeting attendance-32 people First newsletter published-March 15,1975 Homebrew computer Club meeting- October 15, 1975 Attendance--80 people Computevs up and running-38 Homebrew Computer Club Newsletter distribution March 1976-600 copies Homebrew Computer Club meeting- June 9,1976 Attendance-2.50 people Computers up and running-101 Homebrew Computer Club meeting- January 19,1977 Attendance-240 people Computers up and running-182 Homebrew Computer Club Newsletter distribution January 1977-1500 copies According to Gordon French, the Homebrew Computer Club is the oldest major hobbyist club in the world. Gordon's garage was the location of the first meeting. The Wall Street Journal published a front page article Friday, February 4,1977 titled: Home Input, Thecomputer moves #7@mY COMPUTER FAIR From the Corporation To Your Living Room. The article by David Gumpert, HCC Newsletter/~ol.2, Issue 14/February 16. 1977 0 l2e survey hcc1 homebrew computer club At the meeting January 19, 1977 This survey was taken during the Homebrew Computer Club regular meet- ing on January 19, 1977. Approximately 240 people attended the meeting. The survey shows a remarkable number of personal computers in use by the club with many systems running with 8K bytes or more of memory. Seventy-five percent of this group own computer systems. Pro- jecting this percentage of computers in operation to the 1500 people that receive the Homebrew Computer Club NEWS- LETTER would indicate 1125 computers owned by the group. There is plenty of room for error in this type of projecting but it is a very good indication of the investment of club members in personal computer products. 0 SURVEY STATISTICS Systems With Total Systems 8K and Up Manufacturer a wild-eyed production in TECHNIFUNK - UMSAI 8080 ALTAIR 8080 PTC SOL 5 POL YMORPHICS 88 5 OTHER 8080 SYSTEMS APPLE 6502 SPHERE hcc meetings AMI BOARD JOLT Homebrew Computer Club Meeting SW TECHNICAL PRODUCTS Schedule For Remainder of 1977 KUM 0 THER 6800/6502 S YSTEMS F8 March 2, 16 and 30 280 April 15 and 29 8008 May 13 and 25 TTL June8and22 BIT SLICE July 6 and 20 RCA 1802 LSI 11 August 3,17 and 31 OTHERS September 14 and 28 October 12 and 26 TOTAL November 9 and 23 December 7 and 21 ADDITIONAL SURVEY STATISTICS All dates are subject to change or can- Systems with 16K and up memoy 52 cellation. If a change does occur, advance Systems with 32K and up memoy 11 notice will be published in the NEWS- Floppy disc systems 16 LETTER if time permits. two HCC Newsletter/Vol. 2, Issue 14/February 16, I9 77 Extensive documentation and excellent assembly instructions are included. Addi- club member tional AM1 S-6834 EPROMs are available for the following prices: 10 or morel $17 ea., 5 - 91$18 ea., 1 -41$19 ea. For develops EPROM more information write to Gary at P. 0. Box 1133, Ben Lomond, CA 95005 or, if you are really desperate, give him a buzz bd. at (408) 336-2495 by joel miller do you like this format? let us know Gary Mahoney, a Homebrew Com- puter Club member, has just announced his PROROM 8K Memory Module is ready for shipping. Not satisfied with existing EPROM memory board kits, Gary decided to design and manufacture his own to incorporate a number of useful computer features not found in other kits. Not only is this kit less expensive than the others, it has many unique and useful music journal features. PROROM is an 8K memory board with 7%K of 6834 EPROM, %K of RAM, The COMPUTER MUSIC JOURNAL and a built-in EPROM programmer. It is is devoted to the development of com- fully S-100 bus compatible and can be puter systems which are capable of used to hold and run BASIC. PROROM producing high fidelity music. The follow- will transfer data from nonpermanent ing topics will be covered: RAM memory, or a keyboard, directly will work just fine-another important composition of music using a computer into the non-volatile EPROM memory feature not found in other EPROM boards. - contained in the PROROM board. Once Why 6834 EPROMs? The AM1 S-6834s production of natural sounding timbre of quality of tone by the data is stored in EPROM, it is forever are used for a number of reasons. The first Fourier series synthesis protected from power-downs, accidental is price. Very simply, the 6834 is cheaper. FM synthesis and other methods which take or intentional. The price per bit for a fully stuffed a small number of program steps PROROM is fully compatible with an PROROM is 4h per bit. The nearest com- - ALtair, IMSAI, PTC or any other S-100, petitor uses the 2704 and his price (figure design- of real time playing instruments 8080-based computer. PROROM's power it out for yourself) is 5h per bit. But, real time input controllers such as keyboards, requirements are well within S-100 bus according to Gary, price isn't the only .-iovsticks, . and new controllers specifications. reason the 6834 was selected. The 6834 circuit design of computer controlled oscillators A thoughtfully included on-board %K erases to 00 in all bit locations which are highspeed multiplication 16 bit X 16 bit '16 of 6810 RAM provides a convenient area NO OP instructions to an 8080. So, any -bit product in less than 200 ns for stack and scratch pad. This means number of bytes can be programmed at a r&w of hardware components valuable little areas of other RAM boards time. You can program one byte or all Homebrew computer music instruments dxal filter in^ don't need to be used. If you have used 7%K. In other words, you can burn in a - < - anybody else's PROM board, you know little bit of code, leave some blank area diaital reverberation just how handy an extra 512 bytes of for later use and burn in another block. resolution, high speed digital to analog on-board RAM can be. Since the 8080 sees the non-programmed converters- and sample and hold devices The flexible system monitor included area as NO OPs, the blank area can be analysis- of acoustic instruments with every ki:t, transfers data from RAM used to modify or update the program at psychoacoustics using a transfer routine or inputs data a later date. -rnuszc theory which would be more easily real- directly into EPROM from the keyboard. Although not spec'ed as fast as some ized with a computer than with traditional The monitor keyboard loader allows any other EPROMs, the 6834 is fast enough music- instruments number of strings to be run right into to let an 8080 run full speed without a descriptions of presently existing computer EPROM without messing with RAM. wait state for memory access. Programs music- systems Double-check routines verify that all as large as 7%K can be loaded into RAM reviews of books about computer music, EPROMs have been fully erased and that in less than one second.