Whatever the goal in DIY, when automating designs, black pixels or punched holes are selected and knit, while white pixels or unpunched holes are not selected, and used to produce textured, color-patterned knits, or serve as guides to added actions when combined with the knit carriage cam settings.
Depending on the structure, there may be rules or limitations to the pixel distribution that are at times also combined with specific color separations.
Downloads to machines using assorted methods allow for programming up to the width of the bed, 200 needles on the 4.5 mm machine.
Slip stitch programming can be substituted for hand selection when planning short rows.
My first electronic machine was a Studio model. A few mylars from that time are still in my present inventory. This scan shows two repeats used in what would become a sideways knitted skirt.
I tended to scribble on mylar sheets as I did later on my Passap technique Manual printed pages.
Testing smaller repeats helps to troubleshoot possible issues, our tolerance or patience in planning and executing the imagined results, and deciding whether a larger trial is worth it.
My first experiments with the automated short row technique were in producing sideways knit garments, a batwing sweater, and a calf-length skirt.
Depending on the distribution of pixels, it is sometimes easier to fill in areas with black pixels and invert the color if needed, using built-in machine functions. 
The skirt was knit using the top repeat, doubled in width, color reversed, with the speckled rows slipping for one of the horizontal stripes, tucking for the other, forming permanent folds.
There are many previous blog posts on automating “doilies” and circular shapes.
Other slip stitch patterns may be brought together in the programming for sideways shaping (presently avoiding the math involved when gauge matters).
3D printed slider, drop stitch lace review introduces a racked shape repeating in continuous sequences on a fixed number of needles.
There are ribber guides, not always necessary to use, but at times useful in tracking the process correctly.
The previous racking sequence in the planning stages: 
the shapes 
are formed by manually positioning needles on the ribber.
Automating the potentially circular shape, which, after angle and gauge calculations, may be extended to form a sweater, skirt, or other item.
The test repeat: 44X22 
may need to be mirrored horizontally, as in my 930, depending on the machine model and the download software used.
The knit bed produces the background, and the ribber picks up loops that will result in the enlarged stitches when dropped.
Considering the short row method and small stitch count, while the shapes were retained, racking positions were reduced, thus reducing their size. 
Air knitting, practicing racking movements as they relate to the top bed, before actually proceeding with the knit test, ensures the process starts with needles on both beds in the proper placements.
End needle selection is canceled, since the slip stitch setting is used on the top bed, where there are needles out of work.
Half pitch is used, placing needles on both beds between each other.
The first preselection row is to the left, with pairs of rows shaping the knit from left to right, starting with needles on the right pushed back to B away from the carriage every two rows until the process is reversed and they are returned to work.
For pattern knitting, the knit carriage is set to slip/slip.
The ribber carriage is set to N/N to pick up loops, at rest on the left when the sequence is completed, and uncoupled from the knit carriage if used to drop the loops for two passes. On its return, it is paired with the knit carriage again and is set to slip/slip to allow rows of knitting only on the top bed, 5 in the swatch.
Racking happens every row, while the top bed performs its own programmed thing.
In progress, if racking has been performed, the stitches will appear slanted to one side or the other, like normal rib, if it has not.
Ribber needles may not be brought above the B position combined with racking; they would collide with needles beside them on the top bed.
Light colors make it easier to see and identify successful stitch formations.
The best yarn to use is a smooth one that will retain its shape with blocking.
This yarn is a random off-the-shelf wool from an unmarked cone.
Because there is so much happening in a relatively small area, the surface bubbles. In some cases, that bubbling can be the intended design feature.
The racking indicator was used as a guide to determine when the point was reached to drop loops, change settings, and knit X# rows on the top bed alone, followed by setting the ribber carriage to knit once more, reversing racking positions, and repeating the process. 
Using the same slip stitch repeat on the top bed, simplifying the drop stitch shapes to 4-stitch 4-row blocks.
The yarn used in this case is a 6/15/1 rayon, knit at tensions 7/2, one that may be killed with no spring back with blocking, as opposed to wool, with a very different result.
The ribber on N/N forms loops for 4 rows, they are dropped, and the carriage is changed to slip/slip for 2 rows.
The stitches can be selected and brought into work manually; if so, a needle tape may be of use to guide the hand selections. A piece of tape, as shown on the left, keeps edge needles from mistakenly being brought into work.
Racking can be used to move the group of 4 stitches into position, avoiding hand selection, with a start at position 10, to 4, and back. 
The ruffled effect with the knit at rest. 
Horizontal lines or stripes of dropped stitches can be combined with other stitch types, i.e., tuck or lace, for various end uses. 
Combining the horizontal lines with automated short row shaping: these images show some drop aka long stitch designs which were developed and used in a group of limited edition items. 
This Passap Duomatic pattern was the source of inspiration.
I do not have notes available from that time.
Here is a present approach for automating the repeat on a Brother electronic.
Again, starting with a small swatch, testing for the tightest tension possible.
Using a familiar yarn eliminates the possibility of any issues occurring due to only the new fiber choice.
Patterning occurs in pairs of rows for an even number of total design repeat rows.
Here, 34 stitches produced a width of 6.75 inches; there is a 5-stitch vertical border on the straight side edge. 
The repeat can be programmed for any width or only for the number of needles in use by adding all black pixels on the right.
End needle selection is canceled, and the first preselection row is from right to left.
The 30X16 PNG 
required horizontal mirroring on the 930.
To avoid dropping the stitches on needles that are skipped on the top bed, or accidentally bringing up extra needles in work on the far right, a piece of tape can be placed on the ribber bed above the butts of needles directly below them.
All other ribber needles will knit for 4 rows, loops are dropped, the ribber carriage is switched to slip for 4 rows, and only the top bed will knit on all needles. The process is repeated.
As the knitting progresses, needles continue to be preselected across the piece except where those rows of white pixels occur, with them remaining there in the B position.
On the first row that happens, the ribber is set to knit and pick up loops.
When all needles are preselected again, the loops on the ribber are dropped using any preferred method or tool.
The carriage is then set to slip, with all needles returned to the B position, and the top bed alone will knit on all needles once more.
The needle setup. 
The swatch was knit on 20 stitches, 6L to 14R, reducing the border on the right from 5 stitches to 4, and measures 4 inches in width at the curves.
A cumulative list of the blog posts related to this topic may be found at the bottom of the 3D printed slider, drop stitch lace review.