The eprom programming adapter will support 27C322 (4Mx8-bit), 27C160 (2Mx8-bit), 27C800 (1Mx8-bit) 27C400 (512kx8-bit).

Converts the mask- EP- EEP- ROM pinouts of the above parts to the JEDEC pinout of 27C4096 EPROMs (as supported by TL866 USB programmer, and possibly other cheap programmers too). The TL866 programmer is supported through its MiniPro software by selecting '27C4096' device and disabling 'Check ID'. You may also like to reduce VPP Voltage to 12.50V (check your device data sheet).

The TL866 has only a 40-pin programming socket, the extra address pins on 27C800 27C160 are configured manually via dip switch:

  • 27C400:no need to set dip switch, program all 512kB in one pass.
  • 27C800:program in 2 512kB passes: A18=0 (bank 1), then A18=1 (bank 2)
  • 27C160:program in 4 512kB passes: A19/A18=00,01,10,11 (banks 1,2,3,4)
  • 27C322:program in 8 512kB passes: A20/A19/A18=000,001,010,011,100,101,110,111 (banks 1,2,3,4,5,6,7,8)
Since 27C322 is a slightly different pin-out to the other devices, there is a switch which must be used only for 27C322 devices.


If you cannot program the memory, please check first if memory chip is damaged or insufficiently cleared.