June 1979 — Vol 1 No 5

Overview

The first issue under President John Moon (Urban becomes VP). Moon's opening letter sets four goals: dues structure, special interest groups, club library with documentation standards, and continued newsletter growth. The issue is the densest technical issue to date — Sandy Greenfarb delivers a deep dive into DOS internals (track/sector structure, catalog entry format, the RWTS routine), Susan Eickmeyer documents building a Game I/O breakout box from scratch ("with help from Joe Zakar (my boyfriend)"), and John L. Moon fulfills last month's promise with a long SWEET 16 writeup — Wozniak's "computer within the computer" pseudo-machine interpreter. Bernie Urban reports from the New York Personal Computer Faire, surfacing Apple PASCAL (Q3 1979, $495), CORVUS 10MB Winchester drives, and Nestar's Cluster/One networked Apple/PET/TRS-80 system.

Table of contents

Articles

Editor's letter (page 1) — John Moon

First letter as new President. Thanks Urban for founding work. Outlines four growth goals: (1) sound financial footing (dues, ads, cake sales — "whatever"), (2) special interest groups for hardware, languages, education, business, telecom ("Applenet?"), graphics, (3) club program library with standards, (4) ongoing newsletter maturation.

"Disk Operating System Notes" (pages 2–4) — Sandy Greenfarb

Major reference article on Apple DOS internals, distilled from WOZPAK ("Using RWTS Routine" by Wozniak), CALL-A.P.P.L.E. Mar 79 (Dan Paymar) and Apr-May 79 (Richard F. Suitor). Covers:

• Diskette structure: 35 tracks × 13 sectors × 256 bytes; DOS reserves tracks 0, 1, 2 (DOS itself) and track 17 (catalog) → 403 of 455 sectors available
• Sector map in track 17 sector 0: bytes 56–193 encode per-track sector availability as bit fields
• Catalog entry format (35 bytes each, 7 per catalog sector): pointer track/sector, file type (Text $00/$80, Integer Basic $01/$81, Applesoft $02/$82, Binary $04/$84), 30-byte name, sector count
• Pointer record structure linking each data sector
• Data record internals: Integer/Applesoft start with 2-byte length; binary start with 2-byte load address then 2-byte length
• Experiments: DOS file-placement algorithm (works downward from sector 12 of next unused track, wraps tracks 18→34→16→3); DELETE behavior (catalog byte 32 becomes byte 0, then byte 0 → $FF); and a warning about RWTS — direct sector writes don't update the sector map.

"Letting It All Hang Out (the Game I/O)" (pages 5–8) — Susan Eickmeyer

A from-scratch hardware project: build a Game I/O breakout box so you don't have to repeatedly unplug the 16-pin DIP for joystick/paddles/light pen swaps. Patient pin-by-pin explanation (pins 9 and 16 are unused; pin 1 = +5V; pin 8 = ground; pins 6/7/10/11 = paddle inputs; pins 2/3/4 = switches mapped to $C061/$C062/$C063; pins 12–15 = annunciators; pin 5 = strobe at $C040). Parts list (12 phono jacks, 7 16-pin DIP sockets, 4 rocker DIP switches, perf board, ribbon extender, "patience (not available at Radio Shack)") and a complete wiring diagram of the socket-to-socket connections.

Notable opening: "Have you ever been the victim of the APPLE's game I/O?… you've probably thought that APPLE could have come up with something better. They didn't, but you can, and to prove that it can be done by just about any clumsy kid, I even did it myself."

"Converting PIMS for the Apple ][ Disc" (pages 8–10) — Nicholas B. Cirillo (NOVAPPLE)

First NOVAPPLE-bylined article. Cirillo (an MD) describes porting PIMS (Personal Information Management System) by Madan L. Gupta (Scelbi Publications) from TRS-80/PET to the Apple. Key fix: change CHR$(126) (TRS-80 spacer) to CHR$(94) (Apple upward arrow); the line T$ = T$ + ";" + T1$ (DOS comma issue, credited to Bill Kennedy). Cirillo offers cassette copies — but only with proof of book purchase: "I feel strongly about the rights of program authors."

"SWEET 16, the Computer Within the Computer" (pages 10–13) — John L. Moon

Documentation of Wozniak's pseudo-machine interpreter built into the Apple II ROM. Notes that the only existing documentation is five paragraphs and two tables in an early BYTE article ("System Description: The APPLE-II" by S. Wozniak), and that even that doesn't match the shipped implementation. Walks through:

• Invocation: JSR $F689 from 6502 code; SWEET 16 reads bytes following the JSR as its instruction stream
• Architecture: 16 16-bit registers in the first 32 bytes of RAM. R0 = accumulator, RC = stack pointer, RE = status, RF = program counter
• Speed: ~10× slower than 6502 machine code, ~10–100× faster than Integer BASIC
• Full opcode table (RTN, BRA, BCC/BCS/BPL/BMI/BEQ/BNE/BNO/BNN, BRK, RTS, JSR, NOP, SET, TRA, TAR, LBI/SBI/LDI/SDI/LBD/SBD, ADD/SUB/CMP, INC/DEC)
• Worked example: a CALL 768 that clears the screen by SWEET 16, equivalent to CALL -936
• Tease: next month, "a text processing program (including the text editor) for the APPLE"

"How Would You Like to 'Cluster/One'?" (pages 13–14) — Bernard Urban

Report on the Cluster/One distributed system from Nestar Systems (Palo Alto, CA), per President Harry J. Saal's materials at the NY Personal Computing Festival. Up to 15 mixed Apple/PET/TRS-80 stations on a high-speed parallel bus, sharing disk and printer. Central system: dual disk drives, controllers, buffer memory, PSU at $4,500 (single, 630 KB) or $5,000 (double, 1.2 MB). Console is a PET. Pitched for drop-in computer centers and education.

"The New York Personal Computer Faire" (pages 14–15) — Bernard Urban

Apple PASCAL announced for Q3 1979 at $495 — incompatible with Applesoft ROM; uses a language card with 16K write-protectable RAM and 2K auto-start ROM; ships 5 diskettes (Integer Basic, Applesoft Extended, PASCAL). CORVUS Systems 10MB Winchester drive (IMI 7710) for $4,990, expandable to 40MB. Digi-kit-izer graphics input from TALOS Systems ($499 + $99 interface). COMPRINT 912 quiet 9×12 dot-matrix printer $560 (aluminized paper, "Xeroxes very well"). Smart System time-share via modem: $2.75/hr off-peak, FORTRAN/COBOL/SUPERBASIC/PL/C/RPG, electronic mail, UPI data.

Minutes of 5/26/79 — election results (page 15)

New officer slate elected:

Pre-vote discussion: Crosby prefers software (Screen Machine) over SUPERCHIP; Eickmeyer mentioned WOZPAK lower-case chip; Moon mentioned an Apple/Bell & Howell educational deal; Howard Richoux discussed FORTH from FORTH Co.; Urban floated a nationwide "Apple Network." Constitution kept at 3 members-at-large; a Greenapple designee with TBD responsibilities to be added separately.

Club news / events / announcements

• New officers seated
• Next meeting: June 23, 9:30 AM, GWU Thompkins Hall Room 206
• Topics seeded for SIGs: telecom (Applenet), education, business, hardware modifications

Notable advertisements

None this issue (the Research Associates ad does not appear; ads are still ad-hoc).

Key quotes

• "Good things start small and grow." — John Moon (page 1)
• "To prove that it can be done by just about any clumsy kid, I even did it myself." — Susan Eickmeyer (page 5)
• "What is Sweet 16? As the title of this article suggests, it is a kind of computer within a computer." — John L. Moon (page 11)
• "PASCAL will be available in the 'third quarter of 1979'." — Bernard Urban (page 14)

Entities

People: John Moon, Bernard Urban, Genevie Urban, Robert Peck, Mark L. Crosby, Susan Eickmeyer, Sandy Greenfarb, Nicholas B. Cirillo, Howard Richoux, Steve Wozniak, Harry J. Saal, Madan L. Gupta, Bill Kennedy, Tom Bowen, Joe Zakar Topics: DOS Internals, RWTS, Apple Game I/O, Hardware Modifications, SWEET 16, Apple PASCAL, FORTH, Personal Information Management, Networking Apples, Education with Apple References: Cluster/One, Nestar Systems, CORVUS Systems, TALOS Systems, COMPRINT 912, Smart System, NY Personal Computer Faire, PIMS, Scelbi Publications, Computer Hardware Store, WOZPAK, BYTE Magazine, Bell & Howell, Forth Inc.

Connections to other issues

• Forward references: text-processing/editor article promised by Moon for 1979-07 — V01 N06
• Backward reference to Moon's floating-point piece in 1979-05 — V01 N04

Open questions

• Did the "Applenet" / Apple Network idea Urban floated ever take shape in subsequent issues?
• The PASCAL "Q3 1979" prediction — track when it actually shipped.