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Re: [N8VEM: 8193] Re: BIOS update for SBC-188
Sergey --
According to some reference materials, port 0x380 is the following:
----------------------------------------------------------------------------
0380-038F ---- 2nd Binary Synchronous Data Link Control adapter (see 03A0)
0380 r/w on board 8255 port A, internal/external sense
0381 r/w on board 8255 port B, external modem interface
0382 r/w on board 8255 port C, internal control and gating
0383 r/w on board 8255 mode register
0384 r/w on board 8253 channel square wave generator
0385 r/w on board 8253 channel 1 inactivity time-out
0386 r/w on board 8253 channel 2 inactivity time-out
0387 r/w on board 8253 mode register
0388 r/w on board 8273 read: status write: command
0389 r/w on board 8273 read: response write: parameter
038A r/w on board 8273 transmit interrupt status
038B r/w on board 8273 receiver interrupt status
038C r/w on board 8273 data
Rich
On 10/29/10 10:27 PM, "Sergey" <skis...@gmail.com> wrote:
> After spending few hours debugging and using NMI button (http://
> picasaweb.google.com/lh/photo/XjhKarm5ZuwVGAFf8Ozz5g?feat=directlink),
> I finally figured out why MS-DOS 6.22 was hanging on SBC-188.
> Apparently it was trashing UART registers, and BIOS was hanging in
> UART ISR. (Strange, I don't remember any common device at address
> 0380h). Anyhow moving external I/O space one kilobyte up (base at
> 0400h), resolved the issue.
> Now I can boot MS-DOS 6.22 successfully on my SBC-188! (http://n8vem-
> sbc.pbworks.com/f/boot-msdos-6.22.png)
>
> I uploaded updated BIOS to Wiki - BIOS031-Sergey.zip. Please refer to
> the corresponding .txt file for more information about changes.
>
> Regarding NMI button: It is a push button with a 10uF capacitor
> connected in parallel, that is connected to B_/NMI and GND signals.
> When using a polarized (electrolytic) capacitors, make sure minus goes
> to GND... This NMI button is a really useful tool for "hard lock"
> issues debugging.
>
> - Sergey
Rich
--
Rich Cini
Collector of Classic Computers
Build Master and lead engineer, Altair32 Emulator
http://www.altair32.com
http://www.classiccmp.org/cini