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Re: [N8VEM-S100:3207] Re: GAL's and PALASM

I was looking at the schematic that you attached previously.

It accurately replicates the schematic illustrated in Figure 5-7
(Page 72) of the Intel 386DX data sheet.

I'm referencing the data sheet at:


I'd like to look at this two ways:

1. Replicate the schematic exactly.
2. Replicate the truth table of Table 5-7 (Page 71)

They'll be slightly difference because the Karnaugh Map logic
minimization shown utilizes a bunch of "don't care" conditions.

I'm also trying set up the PALASM4 simulation environment with
"test vectors". Not only should that test the design - but when
you program the device, the programmer should actually test the
programmed device with the test vectors. It seems like that would
be useful as folks try to figure out the proper settings for their

The two approaches above /should/ pass the same test vectors if I
encode the "don't care" conditions into the simulator.  The test
vectors will be per Table 5-7.

Funny. I used to do this all the time but I barely remember any of it.
Hopefully a running though some examples will help dust off the cob webs.


On 4/23/2014 11:10 PM, John Monahan wrote:
You were right Rob, the path was wrong.  I have F:\DOSBOX as the root directory but use

So I should have had

Using that, the Minimize Boolean option seems to work.   And the F3 now explains errors.

Next question,
Could you write the equations for mA0 and /msXTRQ for me from the attached figure.
I cannot  figure out how you get more than one layer down without using brackets in these equations.


-----Original Message-----
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Rob Doyle
Sent: Wednesday, April 23, 2014 9:55 PM
To: n8vem...@googlegroups.com
Subject: Re: [N8VEM-S100:3205] Re: GAL's and PALASM

I think we have the same directory layout but I've mounted my "J drive" differently.

I have:

PDS files are in J:\S100

Environment variables are:


The trailing slash on PALASM variable is important - but you seem to have that correct.

After compiling, there is an note at the bottom of the screen about:


When the path is wrong and I press <F3>, I get a notice about which EXE palasm can't find.


On 4/23/2014 6:51 PM, John Monahan wrote:

It's been so long ago since I did that MSDOS path stuff!

Here is how I actually have my PALASM4 setup It's on drive F:
The actual PALASM.EXE file is in the directory F:\DOSBOX\PALASM
   That directory has sub directories
\S100  <- my GAL .PDS files

These directories were setup that way during the install (except the S100 one).

The only PATH & SET scripts I have are:-


Does seem screwed up Rob, now that I see it.
What do you have?


-----Original Message-----
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com]
On Behalf Of Rob Doyle
Sent: Wednesday, April 23, 2014 5:32 PM
To: n8vem...@googlegroups.com
Subject: Re: [N8VEM-S100:3194] Re: GAL's and PALASM

On 4/22/2014 2:52 PM, monahanz wrote:

However if I set “Y” for “Minimize Boolean” in the Compilation
Options,  the compile does not give an error but no .JED file is


Bob, I'm just learning how to use PALASM4.  What I'm trying to figure
out is how to emulate in software the circuit attached here:-

Funny.   I was going to follow up on this.

But first I wanted to play with some of my 'known good' Heath H89 PAL designs.  To my surprise, PALASM4 didn't generate a .JED file...

Once I set the DOS PATH statement correctly, everything worked.

The executable sequence should be:


With the path is not set correctly, PALXPT does not execute and the JED file is not created.

Can you verify?

I'll follow-up on the memory decoder question soon.


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