E2R16v2.2 - 27C400/800/160/322 programming adapter for Minipro TL866

Submitted by GG on Thu, 09/23/2021 - 17:39
Project Status

E2R16 V21The Minipro TL866 is very popular among hobbyist because of its low price and ease of use. Its list of supported chips is however somewhat limited compared to more expensive professional programmers. The E2R16v2 adapter adds support for the ROM pinout compatible EPROM of the 27C400/800/160 and C322 series.

The design is based on the original E2R16 V2.1. It remaps the 27C4096 pins to the corresponding 27Cxxx pins. A 4-bit dip switch is used to select the 512KB bank to program for the larger chips.
A18 and A19 are trivial, they default to low and setting the corresponding switch to ON will set the address line high.
The circuit on A20 is necessary because pin 32 is assigned to VPP on the C800/C160 and to A20 on the C322. On the C322 the programming voltage should be applied to pin 13 (OE#). Dip switch 4 selects the C322 mode and re-routes VPP to the correct pin. D1 and R7 allows OE# from the programmer to work as expected while blocking the VPP voltage from flowing back into the programmer. Q4 and R12 prevent VPP from interfering with OE# during C322 reads and address the compatibility with some TL866. R11 is necessary to ignore A20 on while not in C322 mode.
R13 has been added to addresses compatibility with some newer TL866 II+.

Minipro Software

EPROM Programming

To use the adapter to read or write 27Cxxx EPROMs select 27c4096 and de-select "check ID" in the Minipro GUI. Set the DIP siwtch according to the 512KB bank that need to be read/written. Additionally, for programming make sure the section "IC Config Information" is set according to the datasheet of the specific EPROM being programmed.
Then read and write as usual. Repeat for every 512KB bank.


Qty Ref Des Package Value
1 U1 DIL 42 or 48 pin socket
2 U2 SIL 20 pin 100mil (2.54mm) pitch male headers
3 Q1,Q2,Q4 SOT-23 MMBT3906 PNP transistors
1 Q3 SOT-23 BSS138 N-channel mosfets
1 D1 SOD123 1N4148 diode
2 C1,C2 1206 0.1uF 16V X7R capacitors
9 R3,R4,R5,R6,R8,R9,R10,R11,R12 1206 10k ohm resistors
1 R7 1206 2.2k ohm resistor
1 P1 DIL 4-position DIP switch
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