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Re: DELL System 200 (and others) HIMEM.SYS (MS-DOS 5.0+) GATE A20 ERROR

Posted: Mon 15 May, 2017 11:43 am
by Battler
Lotus 1-2-3 v4.0 for DOS hangs on splash screen, but this happens with all models and CPUs in PCEM, I tried a copy of the same virtual hard disk in Virtualbox and there runs OK...
Yeah the CPU emulation is far from perfect. There's also another issue that affects all emulated CPU's from 808x to 386, and that's the prefetch not working right, which causes, on 808x (probably also other CPU's but 8088mph is not really designed for those anyway), 8088mph's credits to hang (they work on real hardware and DOSBox), and on all the affected CPU's, SnatchIt to hang (works on real hardware and PCE). I reported the issue to SarahWalker last year, but so far it still hasn't been fixed.

Re: DELL System 200 (and others) HIMEM.SYS (MS-DOS 5.0+) GATE A20 ERROR

Posted: Mon 15 May, 2017 4:55 pm
by SarahWalker
I don't remember you reporting that. Link to the thread?

Re: DELL System 200 (and others) HIMEM.SYS (MS-DOS 5.0+) GATE A20 ERROR

Posted: Mon 15 May, 2017 5:03 pm
by Battler
- SarahWalker: I reported it to you on IRC last year and you said you'd look into it. But if needed, I'll create a thread too.

Re: DELL System 200 (and others) HIMEM.SYS (MS-DOS 5.0+) GATE A20 ERROR

Posted: Mon 15 May, 2017 5:19 pm
by SarahWalker
I'm amazed you actually expect me to remember things mentioned briefly on IRC a year ago.

Re: DELL System 200 (and others) HIMEM.SYS (MS-DOS 5.0+) GATE A20 ERROR

Posted: Mon 15 May, 2017 5:48 pm
by Battler
You're right. :p Well I just opened a bug report thread about that. I should have done that back then already.

Re: DELL System 200 (and others) HIMEM.SYS (MS-DOS 5.0+) GATE A20 ERROR

Posted: Fri 29 Dec, 2017 10:48 am
by roadrash
I know this is a old thread buts its interesting that recently my "REAL" Dell system 200 started giving me this error whenever I turn it on. I am suspicious that it is the Keyboard controller chip which on these is a Intel D8742 which is more than just a controller its actually a small computer in a chip that is used to control a few things besides the keyboard. Is also a Eprom and has some firmware/bios programmed into it. My problem is, I can buy a new chip, but without this firmware programmed into a new chip, the computer will not work and I cannot find any source or information about this firmware anywhere not even Dell. There is a very slight chance the firmware might still be in my old chip and I will be sending it to a friend to see if he can dump it out and then program a new chip with it. If he cant get it out, I will not be able to fix this immaculate and once perfect working Dell system 200 and what a shame that will be. I wonder does anyone know anything about this firmware or where I might be able to find it like another still working Dell system 200 or maybe in the code of this emulator. This firmware really needs backed up for the future or there will eventually be no working machines like this left.
Any help I will be grateful and you will help preserve this now rare machine.

Re: DELL System 200 (and others) HIMEM.SYS (MS-DOS 5.0+) GATE A20 ERROR

Posted: Fri 29 Dec, 2017 11:18 am
by SarahWalker
It's possible (though unlikely) that I may still have the keyboard controller from the System 200 board I used to own. I won't be able to look for it until the new year though. If I do still have it I'm happy to let you have it.

Re: DELL System 200 (and others) HIMEM.SYS (MS-DOS 5.0+) GATE A20 ERROR

Posted: Mon 15 Jan, 2018 4:14 pm
by roadrash
SarahWalker wrote: Fri 29 Dec, 2017 11:18 am It's possible (though unlikely) that I may still have the keyboard controller from the System 200 board I used to own. I won't be able to look for it until the new year though. If I do still have it I'm happy to let you have it.
Oh wow if you could find it I would be ever so grateful. Its just been confirmed that the keyboard controller is faulty and unfortunately is seems the failure is caused by deterioration of the memory section which is where the firmware is stored. This is what happens to old Eproms. Its just a shame I didn't know this before it happened as I now have no way of getting it out of my chip. So if I cant get it from another chip my Dell may not be repairable. Ive just downloaded the code from my Dells BIOS roms and given it to the Vintage computer forums to keep in case they ever fail on anyone elses Dell which will happen at some time. But its too late for my keyboard controller. Please have a good look for it thanks.