TENOR Model 763

The Tenor Model 763 is a simple EPROM programmer for 1702A EPROMs. TENOR built this unit as part of an industrial control system.

This programmer in unusual in that it programs 16-bits at a time however the 1702A is only an 8-bit device. The data from the top row of switches is programmed at the address displayed, the data from the bottom row is then programmed at the current address + 128 decimal. This makes more sense when you look at the programming sheet for the industrial controller as it uses 16-bit control words.

To make things even more confusing the unit originally had the LS bit to the left with the MS bit to the right. I modified the unit to swap the bits to a more normal orientation (LS bit to the right, MS bit to the left). I've relabeled the switches on the unit for either HEX or OCTAL input.

To program a 1702A the following sequence is used:

Insert a blank 1702A
Set the mode switch to RD (Read)
Plug in the unit
The address will auto reset to 0x00
Press step to increment through all addresses to make sure the part is blank, the LEDs above the switches will show the output. The top row shows address 0x00-0x7D while the bottom row shows 0x80-0xFF
Press Reset to set the address to 0x00
Set the mode switch to WR (Write)
Toggle in the data for address 0x00 on the top row of switches.
Toggle in the data for address 0x80 on the bottom row of switches.
Press LOAD - The two addresses are programmed.
The address auto-increments to the next address.
Enter the data for address 0x01 and 0x81, Press LOAD - repeat 126 more times.

I successfully programmed the KEX monitor EPROM for my MMD-1 using this programmer.

Click a picture for a hi-res version