"Write and step are active" error message

[David Waine]

Hi

I am working with a Rev D board and this is my first attempt at drive emulation.

When I start the emulation program as follows;

mfm_emu -c 100 -d 0 -f test -h 4 -i

I get this error message;

[Preamble not shown]

**Write and step are active, is J2 cable reversed?**

This happens even when nothing is connected to J2.

I have read someone reported similar but RP1 & 2 are soldered fine and don't have any dry joints.  Checking RP1 pin 1, it's at 3.5V.

Reviewing the circuit diagram and using a 'scope, I can see that U2 pin 19 is always high (*EMU_EN).  Should it be low when the program is running?

I have checked that my BB Black is inserted correctly.

I am running the following version;

 mfm_emu -v
Board revision C detected
Version 4.14
Program requires options: file drive

[I'm actually using rev D]

If anyone could help, I'd appreciate it.

Thanks.

Dave

[David Waine]

As a footnote, I tried out the following python program, just to see if I could toggle the *EMU_EN pin;

import time
import Adafruit_BBIO.GPIO as GPIO
pin = 'P9_12'
GPIO.setup (pin, GPIO.OUT)
while (True):
        GPIO.output (pin, GPIO.HIGH)
        time.sleep (0.2)
        GPIO.output (pin, GPIO.LOW)
        time.sleep (0.2)

And monitoring U2 pin 19, it toggles fine.  So I think I don't have a hardware problem with the MFM board in respect of *EMU_EN.

[David Gesswein]

Set you run setup_emu? You will get that error if you haven't run it
before running mfm_emu. I put in code change in later software that
detects if you haven't run it.

http://www.pdp8online.com/mfm/revb/revb_board_build.shtml

> --
> You received this message because you are subscribed to the Google Groups "MFM Discuss" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to mfm-discuss...@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/mfm-discuss/f752de36-469e-4ae1-93de-13540b2e6466n%40googlegroups.com.