No VIO Found

208 views
Skip to first unread message

Maker Melissa

unread,
Jun 21, 2021, 1:23:16 PM6/21/21
to IMSAI 8080esp
I have my kit assembled and running fine. However, due to issues with the ESP32 firmware and the SD card failing, I needed to reprogram both from scratch using the update instruction, which appear to work fine for the most part. However,  the virtual CRT does not work (it remains black). 

If I type VMODE, I get NO VIO FOUND.

If I type stat CON:=CRT: I also get NO VIO.

In the environment I have ROM2=mpu-a-vio-rom.hex so I would think it would be loading. Is there something different about the updated firmware/SD image that I need to configure to get the VIO to work?

Thanks,
Melissa

Maker Melissa

unread,
Jun 21, 2021, 1:33:31 PM6/21/21
to IMSAI 8080esp
Never mind, I figured it out. I swapped the values of ROM1 and ROM2 and now it works.

udo....@freenet.de

unread,
Jun 22, 2021, 5:37:53 AM6/22/21
to IMSAI 8080esp
Glad you figured it out already. Explanation for others which might run into this sometime:
The VIO ROM contains a signature and the CP/M BIOS checks, if the signature is there. So the only reason why
you get the no VIO found error is because the VIO ROM was not loaded.

TheHighNibble

unread,
Jun 24, 2021, 3:30:47 AM6/24/21
to IMSAI 8080esp
| I swapped the values of ROM1 and ROM2 and now it works.

That works too. 
Only one ROM file is loaded upon boot.  
The intended method is to arrange the ROM files you'd want to use and assign them as ROM1, ROM2, ..., ROM7
Then use the startup configuration mode to select between the ROMs by setting the three (3) NVS_BOOT_ROM bits in the configuration word according to:

Mike Studer

unread,
Mar 27, 2022, 11:29:20 PM3/27/22
to IMSAI 8080esp
Details: Edit the /imsai/conf/boot.conf file on the SD card. Swap the ROM1 value with the ROM2 value.  

Derek Osborn

unread,
Jan 29, 2023, 6:30:24 PM1/29/23
to IMSAI 8080esp
Howdy, this link:


Just goes to the overview page:


do you have anything that explains how to select the various roms during config?  I started life on DOS 2.11 so the IMSAI is new to me and Im not a programmer.

udo....@freenet.de

unread,
Jan 29, 2023, 7:33:56 PM1/29/23
to IMSAI 8080esp
You select the ROM's with some bits in the NVS you need to setup. Appended is a sheet that shows how to set the bits.

Boot Switch Settings - V4.1.pdf

Derek Osborn

unread,
Jan 29, 2023, 8:05:32 PM1/29/23
to IMSAI 8080esp
Cheers, that is very helpful.

TheHighNibble

unread,
Jan 30, 2023, 1:01:45 AM1/30/23
to IMSAI 8080esp
As of the V1.10.0 firmware release in October 2022 there is no longer a NVS_BOOT_ROM setting.
and in the new version of the Configuration Guide  at https://thehighnibble.com/imsai8080/configure/

For people will on older firmware, and not ready to upgrade, the old version of the Configuration Guide is still available at https://thehighnibble.com/imsai8080/configure/old_version_prior_v1.10.0/
So the link to the information about the old NVS_BOOT_ROM setting is thill there, it just got moved to: https://thehighnibble.com/imsai8080/configure/old_version_prior_v1.10.0/#bootrom-configuration

Sorry but I can't go back through the forum and update old out-of-date posts.

The document Udo provided is therefore now, unfortunately, out of date.

However the good news is that the new NVS_MEMORY_MAP bits in the NVS storage perform almost exactly the same role, but now index into the Memory Maps (https://thehighnibble.com/imsai8080/configure/#memory-maps) in the system.conf file. Whereas the old NVS_BOOT_ROM indexed a series of environment variables previously set in the boot.conf file.

This might all seem a little "specific" but is done for good reason and to be in-step with the upstream changes in Z80PACK.
Reply all
Reply to author
Forward
0 new messages