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Verfügbare Sprachen
Verfügbare Sprachen
The 63B09E is interrupted at about a 250Hz rate at the NMI input by the recorder
motor strobe signal, RECM®*. (Note that the RECM* signal is activated every 250Hz
regardless of whether the recorder is being accessed; when the recorder is idle, a
zero is written into the recorder motor register). The 63B09E can also interrupt the
main control processor by sending a strobe on the external interrupt line, INT*. The
63BO9E is also halted whenever the PGS signal is low, indicating that the main control
processor is in the initialization ROM page, when program is to be loaded into the
triple-ported RAM. The power-up condition is for the 63BO9E to be in the halt condi-
tion.
The Status and Control Register
The conirol register, U4, contains the page selection bits to the triple-ported memory,
PGO, 1, and 2; the ROM page selection bits, PG3 and 4; and the keyboard address
strobe bits, KBO, 1 and 2. It is reset to zero on power-up. The ROM page is divided
into 4 pages of 32K bytes each. PG4,3=00 indicates page 0; PG4,3=01 indicates
page 3, etc. (See description of Datasette for allocation of these pages).
Only the lower four bits of the status register, U5, are implemented. This allows the
main contro! processor to detect low battery condition, recorder option, recorder
home position, and SaO2 option. The recorder option is activated whenever the re-
corder cable is connected to the motherboard (by grounding the REC* signal).
Control Register (U4)
Status Register (U5)
Bit 7, Q8 - Page bit 4
Bit 7
Bit 6, Q7 - Display Bit 2
Bit 6
Bit 5, Q6 - Display Bit 1
Bit 5
Bit 4, Q5 - Display Bit O
Bit 4
Bit 3, Q4 - Page Bit 0
Bit 3
Bit 2, O3 - Keyboard Scan Line 2
Bit 2-0 =
Recorder is in Home Position
Bit 1, Q2 - Keyboard Scan Line 1
Bit 1-1 = Recorder Installed
Bit 0, Q1 - Keyboard Scan LineO
Bit0-0
= Low Battery Condition
The Keyboard Register
The keyboard scan matrix is organized as three rows of six keys. Whenever the cor-
responding keyboard address strobe bit is activated (active low), the state of one row
of the keys can be read on the lower order six bits of the keyboard register, U3. The
upper two bits of the keyboard register is connected to the four position dip switch,
(only two positions are used). They are used to select the SaO2 option and LCD type.
Bit 7-1 = SaO2 Installed, O = No SaO2
Bit6-1
=LCD1,0
=LCD2
1-44
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