[Simh] small footprints & OS/2 and MS-DOS

[Howard M. Harte]

You might have a look at www.beagleboard.org, they have a small ARM- 
based SBC for $150. It's 3" square, and runs off 5V.  I ran Linux on  
it with SIMH, and it works very nicely.  It doesn't have Ethernet on  
board, but a USB Ethernet adapter will work.

-Howard


On Jan 23, 2009, at 2:18 PM, Jason Stevens <neozeed at gmail.com> wrote:

> Well I was experimenting with the idea of a 'small' dedicated system
> to run simh on, when I remember that SIMH used to work on OS/2 and of
> course MS-DOS... I remember compiling it with Watcom's compiler...
>
> Anyways Watcom is nolonger, but OpenWatcom has all the important
> bits..  http://www.openwatcom.org/  Oh and it's free!
>
> Using the OS/2 stuff still in SIMH I was easily able to build versions
> with Watcom that run on OS/2 2.x and of course MS-DOS....
>
> Naturally I think MS-DOS is the smallest and easiest enviroment to
> setup, along with freedos..
>
> There is one change I had to make to the OS/2 code in sim_timer to
> make it work enough to boot the microvax, and run VMS & BSD..  I
> didn't bother reflecting the actual time into the calculations, just
> so that the microvax will pass it's POST and I don't think it really
> mattered... I could be wrong, of course...
>
> Naturally there is no real idling under MS-DOS so I didn't do anything
> in those regards... I do recall that DOS/4GW allows for somewhat easy
> calls into real mode drivers so the next step then is to interface
> with packet drivers to allow network access..
>
> For the curious the code to allow OS/2 / MS-DOS run simh microvax is:
>
>
> //this goes in sim_timer.c
>
> #elif defined (__WATCOMC__)
>
> int sim_os_tick;
> const t_bool rtc_avail = FALSE;
>
> uint32 sim_os_msec ()
> {
> uint32 msec;
> sim_os_tick++;
> msec=sim_os_tick*1000;
> return msec;
> }
>
> void sim_os_sleep (unsigned int sec)
> {
>    sim_os_tick++;
> return;
> }
>
> uint32 sim_os_ms_sleep_init (void)
> {
>    sim_os_tick=0;
>    return FALSE;
> }
>
> uint32 sim_os_ms_sleep (unsigned int msec)
> {
> return 1;
> }
>
> ---- And for what passes as a screenshot..
>
> DOS/4GW Protected Mode Run-time  Version 1.97
> Copyright (c) Rational Systems, Inc. 1990-1994
>
> VAX simulator V3.8-0
> NVR: buffering file in memory
> C:\PROJ\SIMH\WATCOM\VAX.ini> set cpu idle=VMS
> Command not allowed
>
> ←[c
> KA655-B V5.3, VMB 2.7
> Performing normal system tests.
> 40..39..38..37..36..35..34..33..32..31..30..29..28..27..26..25..
> 24..23..22..21..20..19..18..17..16..15..14..13..12..11..10..09..
> 08..07..06..05..04..03..
> Tests completed.
>>>>
> Simulation stopped, PC: 200436AD (JSB @64(R11))
> sim> show cpu
> CPU, idle disabled, 32MB, HALT to SIMH
> sim>
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