Hi Rich (and all), I'm very new to the list, and way out of my league in this conversation, but this is one of the more interesting emails to hit my inbox in a few months. Can you elaborate on the "hack something together" part of the Bios dependency? If there is some novel wiring in there, it may be an opportunity to insert some sort of external debugger (microcontroller based or such). --Even lighting up some external LEDs through an I/O could let you know where or what is happening - though that may be the same as calling INT 03H . -Wil Lindsay On Wed, Jun 10, 2020 at 7:13 PM Richard Cini via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
All –
I’m working on an S100 project with my Gazelle (a VGA board) which is based on a standard Trident VGA chip. The BIOS on the video board relies on a PC BIOS (which doesn’t exist for the Gazelle) so I’ve had to hack something together for it to make it work. The BIOS is barfing somewhere in the initialization, but it’s a hard crash so resetting it to regain control destroys the context. I’m running under MSDOS 2.01.
I remember that there were debuggers like Periscope or SoftICE that could trap NMI, but I need it to be pure character-based like MS-DOS debug. Does anyone know of any debuggers like this? There was one by Paul Vojta, which I have the code for, but that doesn’t trap NMI. I wonder if I could just have the NMI call INT 03H (debug break) since they all trap that.
Any thoughts or help appreciated. Thanks!
Rich
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Rich Cini
-- /* Wil Lindsay Wm.Lindsay@gmail.com www.straytechnologies.com @straytech@mastodon.sdf.org <http://twitter.com/strayTech> */