HP-71b CMT-64E Eprom - Whats under the black goop ?

[KimH]

There were IDS documents describing most all of the 71.

One was the HW IDS - which can be found in several places including the MoHP ThumbDrive.

The bus is 4 bit wide with control signals like Command/Data, Strobe, Halt, Interrupt, DaisyChain in/out, plus 3 odd ones IR14 and OD (Output Disable - or Tri-State Bus) and HALT

The CMT Rom Burner Manual can also be found in several places CMT-71-P01. It uses port 4 where pin 9 is NOT connected to anything

The thing I would like to know is WHERE (which pin) the Program Pulse of 14V for the EPROM goes in - i suspect Pin9.

If anyone has the answer to that question, I would be excited to hear about it.

(03-17-2020 09:33 AM)coitboy2000 Wrote:  I guess the CMT eprom programmer must know exactly how this HP integrated circuit works in order to read and write with only 13 contacts.