When the power of the kit 8085 trading kit is turn on, UP-85 is displayed. How is it possible something is displayed even before entering anything?

  • 2
    \$\begingroup\$ So, you bought a kit that came in pre-programmed and you are surprised it displayed somethings in an LCD display? \$\endgroup\$
    – jDAQ
    May 30, 2020 at 5:10
  • \$\begingroup\$ No, I mean, everytime I switch it on or after pressing RESET button,it displays UP-85. Why is it so. \$\endgroup\$
    – user676260
    May 30, 2020 at 5:29
  • \$\begingroup\$ read the comment from @jDAQ again, very carefully \$\endgroup\$
    – jsotola
    May 30, 2020 at 5:43
  • 1
    \$\begingroup\$ Yeah, it was pre programmed. \$\endgroup\$
    – user676260
    May 30, 2020 at 6:02
  • \$\begingroup\$ @user676260 .... sooo ... pre-programmed == program running on it. So? \$\endgroup\$ May 30, 2020 at 9:10

1 Answer 1


it's probably code in the monitor ROM: something needs to run to make the keypad work.

Entering code by punching in hex or toggling switches gets tedious fast, so trainers for Von-neuman processors like 8085 typically profide a means to load student software into ram from an externmal source (like a PC) and facilitatre this by means of an interface cable and some ROM code

  • \$\begingroup\$ We had something very similar in University for 8051 development//learning boards - there was a bootloader code which allows code to be downloaded into the EEPROM (I think it was another flash memory chip actually) over Serial as opposed to progrmaming the 8051 chip itself via parallel or Serial ISP \$\endgroup\$
    – QuickishFM
    May 30, 2020 at 9:57

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