![](http://pdfasset.owneriq.net/2/5a/25abb1eb-61b8-4ba5-a53e-ae9f7bc444f6/25abb1eb-61b8-4ba5-a53e-ae9f7bc444f6-bg46.png)
As shown in Figure 9-1, the main microprocessor accesses read-
only and read-write memory, and controls the keyboard, LCD
display, and clock. The slave microprocessor controls the micro-
printer, speaker, and external cassette. The cartridge interface has
ports for both the main and slave microprocessors.
Figure
9-1
HX-20 Architecture
ROM
I
I
SOCKET
8KB
6301
MAIN CPU
BARCODE READER
INTERFACE
CARTRIDGE
INTERFACE
-El
6301
SLAVE CPU
CASSETTE TAPE
INTERFACE
POWER
SUPPLY
66