A native slideshow tool for the Apple Lisa Office System. It appears on the LOS desktop as its own icon, opens into a full-window carousel, and displays 680 x 300 one-bit pictures -- photographs dithered on a modern computer and delivered to the Lisa on a floppy or over a serial line. Click or press a key to advance, or let it run itself at one of three speeds. Written in Lisa Pascal with the Workshop 3.0 toolchain; runs under Lisa Office System 3.1 on real hardware.
- Copy Pictures from Floppy (Show menu). Insert a floppy of .PIX files, pick the item, and every picture is copied to the volume the tool lives on. Existing names are never overwritten. The Workshop is no longer needed to install pictures.
- Remove This Picture (Show menu). Deletes the slide on screen. It is a two-step item: pick it once and a note explains; pick it again, straight away, and the picture is gone. Anything else in between cancels.
- Bonus picture packs as floppy images, below. Copy Pictures from Floppy is how they install.
The name honors Bill Atkinson twice over, because this program depends on him twice over.
Atkinson wrote QuickDraw, the graphics library at the heart of the Lisa and, later, the Macintosh. Every pixel this tool puts on the screen -- the window, the menus, and the single CopyBits call that blits each slide -- is drawn by his code, running where he wrote it. QuickDraw on this machine is not a tribute or an emulation; it is the original article, and this program is one more caller.
Atkinson also devised the dithering algorithm that bears his name: a technique for turning grayscale photographs into pure black-and-white images that still read as photographs. Like Floyd-Steinberg dithering, it diffuses each pixel's quantization error to its neighbors -- but Atkinson's version deliberately spreads only three quarters of the error (one eighth to each of six neighbors, discarding the rest). Throwing part of the error away costs some shadow and highlight detail but keeps the midtones crisp and airy, which is exactly right for a 1-bit screen viewed at arm's length. It became the signature look of early Macintosh imaging (MacPaint, HyperCard); on the Lisa's CRT it is, if anything, even more at home. Every slide this tool shows was prepared with Atkinson dithering by default -- his algorithm makes the pictures, his QuickDraw draws them.
And the name is a small pun on "PowerPoint," by way of Teslerpoint (see Thanks): the Lisa was always meant to give presentations.
Bill Atkinson -- QuickDraw and the dither, as above. This tool is a two-part thank-you note.
Tom Stepleton -- his Teslerpoint proved that a Lisa makes a fine slide carousel and inspired this program. No Teslerpoint code is used here (that program is bare-metal 68000 assembly; this one is Pascal on the Office System), but the idea is his. His lisabbs and documentation work also underpin LISACom, this tool's companion.
Alex Anderson-McLeod (alexthecat123) -- his LOS Minesweeper is the template every LOS desktop tool in this family is built from, and his LOS Compilation Base image supplies the Workshop environment and Apple's own ICONEDIT. His LisaFPGA made nightly testing practical.
The LisaList2 community, bitsavers.org, and the Computer History Museum (for the Lisa Office System source release).
Errors are mine, not theirs.
- Apple Lisa running Lisa Office System 3.x (developed on 3.1)
- A way to get a 400K floppy image onto a floppy: a Floppy Emu, BLU, or a Mac that can write Disk Copy 4.2 images. That is all the bonus packs need.
- To make your own pictures: any computer with Python 3 and Pillow (pip install pillow), and either a floppy path as above or LISACom, this tool's sibling, to YMODEM them over a serial line.
AtkinsonPoint_v1_1.dc42 the tool + starter show (1-9) + LISACom 1.1
1_1_Extra_PIX_NASA_AtkinsonPoint.dc42 bonus pack: NASA, pictures 11-24
1_1_Extra_PIX_SciFi_AtkinsonPoint.dc42 bonus pack: science-fiction art, 31-41
1_1_Space_Odyssey_PIX_AtkinsonPoint.dc42 bonus pack: 2001: A Space Odyssey, 51-63
1.PIX ... 9.PIX the starter pictures, loose
lisapix.py picture converter
SLD-*.TEXT, SOURCES.txt Lisa Pascal sources, 1.1
atkinsonpoint_sources.zip the same sources, zipped
Every bonus floppy also carries the 1.1 tool, so any one of them is a complete installation on its own.
Each pack is a 400K Lisa floppy image holding up to twelve pictures (that is the ceiling: a picture is 50 blocks, a floppy has 772). Packs use a block of numbers each so they play in order and never collide:
| Pack | Numbers | Pictures |
|---|---|---|
| Starter show | 1-9 | 9 |
| NASA | 11-24 | 12 |
| Science fiction art of the Lisa era | 31-41 | 10 |
| 2001: A Space Odyssey | 51-63 | 13 |
The Space Odyssey floppy also carries two extra slides filed as 5.PIX and 6.PIX. If the starter show is already installed, Copy Pictures from Floppy skips them (names are never overwritten); they will be renumbered in the next cut.
To install a pack: write the image to a floppy, insert it, open LISA Slide Show, and choose Copy Pictures from Floppy from the Show menu. The show rescans itself when the copy finishes. Pictures you do not want can be dropped with Remove This Picture.
Requests for packs, and packs of your own: post to LisaList2.
Simple enough to memorize:
680 x 300 pixels, 1 bit per pixel
85 bytes per row, high bit leftmost, 1 = black
no header, no padding: exactly 25,500 bytes
Files are named 1.PIX, 2.PIX, ... on the Lisa's boot volume and
play in catalog order (zero-pad past nine: 01.PIX ... 10.PIX,
because the catalog sorts alphabetically). The format is also
described inside the tool itself: Version menu -> Making Pictures.
lisapix.py (in this distribution) converts JPG/PNG to .PIX:
python lisapix.py photo.jpg 1.PIX --fill --preview p1.png
--fillscale to cover and center-crop: fills the whole frame. Best for landscape photographs.--windowletterbox the whole image, uncropped. Best for portraits, documents, and title cards.--ditherfs | atkinson | ordered | threshold (default atkinson; threshold is best for text and line art)--parpixel-aspect prescale, default 1.40 -- the Lisa's pixels are not square, and this keeps circles circular--previewwrites a PNG of exactly what the Lisa will show
Every output is exactly 25,500 bytes; anything else is an error.
Get pictures to the Lisa either on a floppy (any tool that writes Lisa-format files, or add them to an image) and use Copy Pictures from Floppy, or as BINARY files over serial (in LISACom: Receive via YMODEM, RETURN to accept the sender's name). If the slideshow is already open, choose Look Again for Pictures from the Show menu.
Open the LISA Slide Show icon. The first picture appears; then:
- Click or almost any key -- next slide
- B -- previous slide
- A -- toggle auto-advance
- Speed menu -- Slow / Medium / Fast auto-advance
- Show menu -- Look Again for Pictures (rescan the disk), Copy Pictures from Floppy, Remove This Picture (pick twice)
- Version menu -- About, and the built-in picture-making guide
Set Aside or Save & Put Away from File/Print, as with any LOS tool.
The distribution floppy carries the tool and a starter show of nine pictures, so it demonstrates itself out of the box.
The tool: insert the floppy, Duplicate (not drag -- dragging is a move) the LISA Slide Show icon onto your ProFile window, and open it. Five files travel with the icon; LOS manages them. Never drag a tool's icon to the Wastebasket -- LOS deletes the tool's whole hidden file set with it.
The pictures: open the tool from its new home with the floppy still in the drive and choose Copy Pictures from Floppy from the Show menu. The nine starter pictures land next to the tool -- the slideshow looks for its pictures on the same volume it was installed on -- and the show begins. The floppy can then be put away.
If you would rather use the Workshop, the .PIX files are ordinary files and its File Manager copies them too:
F (File-Mgr)
C (Copy)
from: -LOWER-=.PIX
to: =.PIX (or -VOLUME-=.PIX if the tool lives on
a volume other than the boot disk)
-LOWER- is the Lisa's floppy drive; the = wildcard copies all nine in one command. Boot the Office System, open LISA Slide Show, and if it was already open choose Look Again for Pictures from the Show menu.
Six sources: SLD-MAIN.TEXT, SLD-GLOBALS.TEXT, SLD-ALERTS.TEXT, SLD-COMP.TEXT, SLD-LINK.TEXT, SLD-MAKE.TEXT. Format each with fmt_text.py before sending (Workshop .TEXT files are paged, bare-CR), place them in the SLD/ slots, then from the Workshop: R <SLD/MAKE. Menus are matched by position: MAIN, GLOBALS and ALERTS change in lockstep. Every source opens with a REV header (letter, date, one-line change note); when a build error makes no sense, compare REV letters on the Lisa against the files here before anything else -- a stale copy has cost more than one evening.
Three hard-won lessons are baked into this code, left here for the next person:
- A bitmap's rowBytes must be even. 680/8 = 85 is odd; the fix strides 86 bytes per row in memory while the file stays 85. Odd rowBytes puts alternate rows at odd addresses, and the 68000 address-errors on the first word access.
- Pad heap-allocated image buffers. The allocator can place a buffer at the very base of an MMU data segment, and QuickDraw's blitter reads a couple of bytes below baseAddr on non-aligned transfers -- straight into unmapped space. Eight bytes of padding ends a Level 7 bus error that took two weeks to corner.
- Lisa Pascal identifiers are significant to eight characters.
alrtCopyDoneandalrtCopyNoneare the same name to the compiler ("declared twice", Error 100). Keep every identifier unique within its first eight.
Atkinsonpoint began in August 2026 as part of a project to write new native software for the Lisa Office System, alongside LISACom (the serial/BBS tool that delivers its pictures). It was parked for two weeks on a mysterious bus error, then revived when a diagnostic build painted every input to CopyBits on screen and the crash confessed in two photographs -- the first two lessons above. 1.0 shipped on August 25, 2026. 1.1 followed a week later, once it was clear that most people downloading the packs had no serial cable: an Office System tool turned out to be able to read the floppy drive directly, and the Workshop dropped out of the instructions. Everything in this README was verified on a Lisa 2/10 (internal and external ProFile) and a LisaFPGA.
Bugs and ideas: post to LisaList2.