Programmer jumpers - W/Jp1- wire cable to dc2dc_a4, Jp3 (+5V), Jp4 (Vpp)
tsop28c1 jumpers - A,C (256kb); B,D (512kb)
27C256, 27C512
Selected device EPROM > 27Cxxx > …, twp=140mks
dc2dc_a4 jumpers – JpR (Vcc from LM317), JpM (Vcc=5.8V) , JpP (Vpp=11..14V)
Adjust R5 - Vpp=12.8V
Verified chips : ST Micro M27C512B
Electrically erasable EPROM are not supported on tsop28c1.
Chip test results find in chip_test.xls file.
Adjust other Vpp value or change Vcc=6.2V (jumper N), change twp, if required from EPROM datasheets or programming fail.
256k chip read available without dc2dc_a4, some can be programmed. Set jumpers JpK, JpL. (Vcc=5V, Vpp=12V).
How to adjust Vpp ?
Install dc2dc_a4 and eprom adapter without target chip on ezoflash+.
Connect power supply, PC and run SW. Adjust Vpp on LM317- IN with R5
Chips in TSOP-28 package (except electrically erasable) are OTP (one time programmable) and cannot be erased. Only new EPROM can be programmed, all bits of the EPROM are in the logic high state.
Run SW command Blank check to assure all bytes are 0xFF.
Logic lows are programmed into desired locations. Repeat programming (check voltage, increase twp) on logic low programming failure.
Report problems and share your experience on Willem and EZoFlash forums.
