October 28, 2026

MOD_EMUP - using it !! 10-28-2026

I haven't done this in quite a long time. I drag out the computer, monitor, and keyboard and boot it up.

It is a 600 Mhz Pentium III system with 256M of ram. Quite a machine for running DOS. It boots up just fine from the old Fujitsu IDE drive and greets with with FreeDOS and a C: prompt.

I locate the EMUP and cable. I do not plug it in with the system running. One nice thing about DOS is you just flip the power switch to off.

I am reminded that the EMUP has 4 things that I have seen no mention of in the port documentation:

We turn the machine back on and launch the software via: 
cd emup
access
My reason for firing this up is that there are three GAL devices in my second EMUP that I have disassembled and am analyzing: 
U7 - AMD PALCE16V8H-25
U10 - AMD PALCE16V8H-25
U4 - AMD PALCE16V8H-25 (on upper board)
The first two are on the main logic board (the one with the DB25). The third is on the "top" board which has the device socket.

It is entirely possible that these will have the security fuses blown, but we shall see;

The green "on" LED on the EMUP is lit, but both red "good" and "busy" LEDs are off.

I start with U7. I select AMD, PLD, and PALCE16V8H. There are also 16v8h/4 and 16v8/5, but who knows?

It launches PALP1.EXE I type R to read -- all the type selection was already done in the "mother" access program. It seems to work. The "busy" light is lit while reading, but goes off when finished. The red "good" light is now on and it shows a checksum.

I type "3" to save to disk (not S) and give it a filename of emup-u7.jed

U7 gives me a checksum of 06fc
U10 gives me a checksum of 0700
These jedec files are filled with all ones, which suggests that the security fuse was indeed blown

So much for that.

Have any comments? Questions? Drop me a line!

Tom's Electronics pages / tom@mmto.org