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#109469 - 04/28/17 04:39 PM Re: VENIX Disks [Re: rfka01]  
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bsdimp Offline
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So why doesn't the -speed actually speed up the floppy access speed? It seems super slow (much slower than real hardware) w/o -speed and just a little slow with a -speed 10 on the command line. Is this a case of a driver that needs to be tuned, or is there something more systemic in MESS that needs to be addressed?

It also looks like Venix is only seeing 10MB of the 48MB drive (ST-251-1) I've setup, even after partitioning with WUTIL, so I'll have to get to the bottom of that. I think I've seen this on semi-real hardware as well.

And when I boot off the hard drive for Venix after installing, I get a watchdog timer triggering and garbage on the screen. I know there's a stack overflow issue for automatic booting, but this was booting off with the 'W' command. Or is that the issue?

The good news is I can boot Venix 2.0 off floppies, do the install and generally mess around with it, though in a restricted environment. It's going much better than I'd thought it might.

I'll try the BSW enhancements to see if that helps or not.

#109470 - 04/28/17 05:44 PM Re: Requirements? [Re: rfka01]  
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Bavarese Offline
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Quote
So why doesn't the -speed actually speed up the floppy access speed?

Good question. I am open to suggestions. The new floppy code is at least accurate, timing wise (same cannot be said from the WD2010/1010 hard disk controller code i cobbled together).

Quote
And when I boot off the hard drive for Venix after installing, I get a watchdog timer triggering and garbage on the screen. I know there's a stack overflow issue for automatic booting, but this was booting off with the 'W' command. Or is that the issue?

Correct, both 'W' and auto-boot are affected. It is the same bug. A CPU crash (watchdog event) occurs @ the 3rd stage of the boot loader. Unfortunately i cannot find the cause. Also, the third stage pulls tricks i can't fully grasp as a 6502 guy. smile

In short: the Z80 thinks it boots from floppy, when data is piped from hard disk sectors instead. The 808x does something, the WD1010 does something, and somehow too many IRQs fire...so the 808x finally stalls.
The loader binary is hidden in one of the WUTIL.? files of the distribution archive - if someone wants to take a look.
Crazyc?

WUTIL comes with an extended boot loader much more capable than DEC's. Unfortunately, even the latest version (i think it was 3.2) crashes in our emulation. Just like DEC's limited, old one

The 3.0 or 3.1 archive came with Turbo Pascal source. I have it somewhere.

Last edited by Bavarese; 04/28/17 09:23 PM.
#109473 - 04/29/17 01:31 AM Re: Requirements? [Re: Bavarese]  
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PREBOOT.ASM and SECBOOT.ASM contain commented assembler source.
One oddity i remember is that at least 1 geometry value (heads) inherited a wrong value (zero) from one of the earlier boot stages...
Source files

Binaries

Last edited by Bavarese; 04/29/17 01:51 AM.
#109487 - 04/30/17 05:14 PM Re: Requirements? [Re: rfka01]  
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Yea, I have that file. I'll have to take a closer look. Sadly, most zip files from that era give me errors like:
x $README.1ST: Unsupported ZIP compression method (imploded)
when I try to decompress them on modern hardware...

#109488 - 04/30/17 06:07 PM Re: Requirements? [Re: rfka01]  
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Looking at the source, it looks like it includes the Z80 boot code from the MS-DOS diskette (first two tracks). ZFLIP may well be in play, even though we don't need the floppy code to boot from the hard disk, the boot loader appears to put it in place and the rest of the OS depends on it... executing the wrong code during this because ZFLIP is wonky would definitely cause weird behavior, including stack overflow. 8088 processors really hate 8080/z80 code smile

#109501 - 05/01/17 02:51 PM Re: Requirements? [Re: rfka01]  
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bsdimp Offline
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In going through my floppy collection, I've found an alternate copy of Windows. The one that's normally available has issues, I'm told, with VAXmate files being mixed in and gumming up the works. These files are different, and on a set of disks that said "Windows 1.03" on them with a letter saying it is OK to upload them to BBSes dated in 1988. So I thought I'd pass them along to see if they are helpful fleshing out the graphics card at all. Since I think they are kosher to redistribute, I've put them up at github at https://github.com/bsdimp/rainbow100.git for all to enjoy. I have no clue how to install them or anything like that.

#109504 - 05/01/17 06:53 PM Re: Requirements? [Re: rfka01]  
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Bavarese Offline
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Thanks for taking a look. Just for the record, an emulation of the DEC mouse protocol will be needed before we can give Windows 1 a try.

Back in 2012, i compiled some info here. I personally never got a graphics card, nor a DEC mouse - so i can't tell which of the serial ports was occupied.

As these mice were usable together with other workstations, working on them might be of some interest to others.

Last edited by Bavarese; 05/01/17 11:41 PM.
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