Memory Map of MTK-85 Microprocessor Training Kit

The 8085 has 16-bit address lines, i.e. A0-A15. It can access 65536 bytes. The address in hex number is from 0000H to FFFFH. The MTK-85 has two memory chips. The first chip is an OTP (One Time Programmable) ROM, 27C256. This ROM contains the monitor program. The second chip is a 32kB SRAM, 62256. The RAM area is the place where we can enter the program for testing. The RAM is located from address 8000H to FFFFH. Within the first page, 8000H to 8100H, some of the locations are interrupt vectors that relocated from ROM addresses.


Some interrupt vectors are used by system monitor program. Below is the the list of them.

RST 1 system monitor call with opcode CF,

RST 2 monitor testing,

RST 3 monitor testing,

RST 4.5 single step service call.

RST 7 jump back to monitor program.

Key HOME sets the address to 8100H. User can enter the hex code from here. The space from F000H to FFFFH are used by monitor program


Written by Wichit Sirichote,
Last updated: April 21, 2007.