Browse Prior Art Database

Keyboard Repeat Character Entry

IP.com Disclosure Number: IPCOM000086490D
Original Publication Date: 1976-Sep-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Castle, WH: AUTHOR [+2]

Abstract

When a repeat key is depressed, it travels through two levels. The first level is a normal keyboard cycle like any nonrepeat key, as shown in the figure.

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Keyboard Repeat Character Entry

When a repeat key is depressed, it travels through two levels. The first level is a normal keyboard cycle like any nonrepeat key, as shown in the figure.

When a repeat key is depressed to the second level, it looks just like any other keyboard cycle at the start. The difference is that in the second level the bails are held and the character code remains on the keyboard sensor lines. The keyboard strobe which is generated from these sensor lines also remains activated.

On a single keyboard cycle the strobe signal never occurs concurrently with the 85 degree point of the printer feedback (PFB). This is due to the timing of the keyboard and printer.

If a strobe signal occurs at the 85 degree point of PFB, it is used as an indication by system logic that a key has been depressed to the second level. This causes another printer cycle to be initiated, and the character to be printed is the same one used in the previous cycle. This procedure continues until a check at 85 degrees of PFB indicates, by the absence of the strobe signal, that the key has been released.

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