Sharp MZ-3500 - Manual (Page 83)

MZ3500
10. MZ1K01 KEYBOARD CONTROLLER CIRCUIT DESCRIPTION
10-1. Specification of keyboard control
1) Input Buffer
Capacity: 64 bytes
• Key-in data is written to the input buffer first, and is
supplied to the CPU, byte by byte.
• When an overflow is detected, the overflow code is
affired to the key-in data already sent, before being
sent to the CPU.
2) Rollover
• 2 key rollover (exemption in the CTRL mode)
(Entry of the second key depression can be accepted
even if more than one key is pressed at same time.)
• Simultaneous depression of more than three keys is
ingnored.
3) Key bounce
15msec (Key spec is 5-10msec)
(Indicates unstable state as shown in Fig. 3-2 that key
signal does not turn off immediately after releasing of
finger from the key.)
4) Key
5msec (norma), 20msec (max),
15msec (allows for key bounce)
5) DEF Key
Twenty definable keys are available in combination with
the CTRL key.
[ DFK1-DFK10--------------------- (DEF1A-DEF10A)
DEF1-DFK10 in conjunction with the CTRL key
- - - (DEFIB-DEF10B)----------- (DEF1B-DBF10B)
6) Handling of functional symbols and graphic symbols
See the code table.
7) Use of the CTRL key to discriminate RUN and CONT of
the DEB key.
Push the DEB in conjunction with the CTRL key to
start running.
8) Handling of special codes
COPY command: CTRL j 1 | (ten key)
Escape --------------- CTRL |Ci^
BRK -------------------- CTRL I CONT]
11 ) One-step commands
CMD 1 •
CMD 2
CMD3
CMD 4
CMD 5 ■
CMD 6 •
CMD 7
CMD 8
CMD 9 •
CMDO
CMD A
CMDC
CMD D
CMD F
CMD K
CMD L
CMDO
CMD R
CMD S
CMD U
DISP
PRINT
INPUT
USING
IMAGE
GOTO
GOSUB
RETURN
LIST
SEND
AUTO
CLOSE
DATA
RFORMAT#
KEY IN
LOAD
OPEN
READ
SAVE
CURSOR
12) Mode indication on LED
ASCII LOCK
13) REP
Key repetition will take place when a key depressed for
more than 0.64 second. Entry of other keys is permitted
during key repetition. When two keys are depressed at
the same time, an alternate key entry will not be
accepted. This rule does not apply to simultaneous
depression of more than three keys.
9) PRO/OP
Sent to the CPU after power on and when PRO/OP is
changed.
10) HOME key
CTRL HOME] Returns home after clearing the
_____ display screen.
HOME Only the cursor returns home.
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