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View Full Version : Return of the Zenith ZF-158! (AAIIEE! DOS problem.)



Super-Slasher
April 13th, 2004, 07:40 PM
Hehe, decided to toy around with my 8088 system again, especially after finding a 384KB (I think) EMS card for it. That means that I physically have 1MB; the maximum addressable of the 8088 CPU, except I can't access it. I need to turn the EMS on somehow.

I have 6.22 installed, but I was told by someone else that I would be better off using DOS 3.1 because it's more geared to 8088 processors while later version were more meant for advanced processors (286, 386, etc.).

Is this the case? Will I need 3.1 or is there a way to get EMS on an 8088 system with 6.22? If I need 3.1, can anyone help me in this department. I had it on disk, but I can't find it...

:evil:

Terry Yager
April 13th, 2004, 08:09 PM
Hehe, decided to toy around with my 8088 system again, especially after finding a 384KB (I think) EMS card for it. That means that I physically have 1MB; the maximum addressable of the 8088 CPU, except I can't access it. I need to turn the EMS on somehow.

You need an Expanded Memory Manager program (which is specific to the hardware you have). I have a copy of the Zenith EMM, but it will only work on a board made by Zenith (is yours?). If ya need it, send me an email and I'll get a copy to ya (soon's I drag out my media-transfer machine and set it up. The prog is on a 5 1/4" disk).


I have 6.22 installed, but I was told by someone else that I would be better off using DOS 3.1 because it's more geared to 8088 processors while later version were more meant for advanced processors (286, 386, etc.).

It isn't that the later versions of DOS are intended for later-model CPUs, it's the size of the program, and the 8088's available memory that causes problems. The 6.22 version takes up more of your 8088's precious memory. On a '286 and later CPU, DOS can be loaded into upper memory, so it increases the ammount of mem (640Kb<) left for DOS apps. Obviously, you can't do this upper mem trick on the 8088, so DOS 6.22 is just wasting space without giving you any extra advantage.


Is this the case? Will I need 3.1 or is there a way to get EMS on an 8088 system with 6.22? If I need 3.1, can anyone help me in this department. I had it on disk, but I can't find it...

:evil:

Actually, without Extended memory, Win 3.1 won't work at all. You'll have to dig up a copy of Windows 3.0 or earlier. This can be downloaded from various websites. A search should turn it up.

--T

Super-Slasher
April 13th, 2004, 08:15 PM
By "3.1" I meant DOS 3.1, not Windows. Windows is never mentioned throughout my post. :)

Terry Yager
April 13th, 2004, 08:21 PM
By "3.1" I meant DOS 3.1, not Windows. Windows is never mentioned throughout my post. :)

Oh, sorry...my bad. So d'ya need that EMM driver?

--T

Super-Slasher
April 13th, 2004, 08:23 PM
Yes, please. Send it to:

slasher1983@yahoo.com

:D

Terry Yager
April 13th, 2004, 08:27 PM
Ok, I'll try and get it done tomorrow sometime. (It's on a Zenith (OEM) version of DOS 3.20, would you like it sent as a bootable image? I only have the bootdisk, not the Supplemental Programs disk to make it a set).

--T

Super-Slasher
April 13th, 2004, 08:33 PM
Sure, send that too, I suppose, though I wouldn't know how to place the image properly on a disk (360KB, I assume?).

Terry Yager
April 14th, 2004, 05:02 AM
Sure, send that too, I suppose, though I wouldn't know how to place the image properly on a disk (360KB, I assume?).

Yah, 360Kb. That's why I keep a special-purpose media transfer machine around. It's a '386 with 5.25, 3.5 and CD capability. To extract the image, you'll need a 360Kb drive (HighDensity 5.25 don't work very well in creating 360K disks). I use a (freeware) program called TeleDisk to make the images, so you'll need to download a copy from Gaby's CP/M webpage at: www.gaby.de in the downloads/ directory. Oh yeah, the EMM program has to be called from your config.sys, so you'll have to modify that in order to use it. Check out the config file on the disk-image to figger out the command necessary.
About expanded memory:
I noticed you said you have 384Kb of expanded memory to use the full 1Mb available. Actually, you can have more than 1Mb of expanded memory (up to 32Mb under LIM 4.0) because expanded memory resides above the 1Mb boundry and doesn't use conventional (DOS) memory, except for a 64Kb "page frame" which is taken from memory between 640K and 1Mb. EMM uses this page frame as a window into the actual memory, and switches-in the extra memory (64K at a time) as the program needs it. In order to take advantage of EMS, the application has to be written in such a way as to be "aware" of expanded memory. Not all DOS programs can use EMS, so you may never notice any difference in the way your programs run with the extra RAM. BTW, the memory between 640K and 1Mb is available to DOS, but it is "reserved" for certain uses, such as video memory, I/O ports, etc.

--T

Super-Slasher
April 14th, 2004, 10:21 AM
I found a copy of EMM from MS-DOS and installed it into my Zenith, and it appears that I now have the full 1MB of memory addressable by the 8088 processor, but that leads me to another question.

Is this RAM totally useable by the system? What I mean is, is this EMS memory (384KB) as readily accessable as the base 640KB RAM is to the system, or can it be only accessed by high-memory devices, drivers and files?

I'd still like to see the Zenith boot disk and EMM file, but this one seems to work as well. Strangely enough the EMM seemed to pick up the memory board without any parameters to be set, almost like plug and play. I set some parameters, anyways, to be safe.

Terry Yager
April 14th, 2004, 06:44 PM
I found a copy of EMM from MS-DOS and installed it into my Zenith, and it appears that I now have the full 1MB of memory addressable by the 8088 processor, but that leads me to another question.

If it says it's working, then it prob'ly is, I'd imagine. Although the 8088 can only address memory up to 1024Kb, the Expanded Memory Manager is able to "trick" the CPU into using memory which resides above 1024Kb. It does this by setting up a "page frame" within the 8088's 1Mb address space (in the "reserved" memory area, 640K-1024K). All that the CPU "sees" is this page frame, so it doesn't know that it is using higher memory. The memory manager maps the high memory into the page frame, thus into the 8088's address space. Therefore, you can use much more memory than just the 8088's 1024K (up to 32Mb), so if your board can hold more memory, feel free to use as much as you can put on it, or even add another EMS board someday.


Is this RAM totally useable by the system? What I mean is, is this EMS memory (384KB) as readily accessable as the base 640KB RAM is to the system, or can it be only accessed by high-memory devices, drivers and files?

Is the RAM available to the operating system? Yes, but only with applications which are "aware" of EMS, which know enough to look for the page frame in the reserved area. Programs like spreadsheets, (Lotus 123) CAD programs, (AutoDesk) some games, and other memory-hungry apps generally can use EMS memory. Windows 3.0 is aware of Expanded memory, and uses it, so any program running under Win3.0 is using the memory too. Usually the documentation of those old programs will tell if they use expanded mem or not. DOS by itself does not use expanded memory, only the apps that run under it do. Later processors and apps use Extended memory, but a memory manager for such systems, like EMM386 use extended memory to emulate expanded memory, for backwards-compatability with older soft- & hard-ware that uses expanded memory and not extended. Here's a link to more EMS info:

http://wombat.doc.ic.ac.uk/foldoc/foldoc.cgi?LIM+EMS


I'd still like to see the Zenith boot disk and EMM file, but this one seems to work as well. Strangely enough the EMM seemed to pick up the memory board without any parameters to be set, almost like plug and play. I set some parameters, anyways, to be safe.
Of course, you want your DOS startup banner to read "Zenith MSDOS 3.21", just for authenticity's sake. So check yr email, already...

--T

Super-Slasher
April 14th, 2004, 07:05 PM
Now a new problem suddenly manifested itself. I get an "internal stack overflow" and pairity errors when running large executable files. *sighs* 8088 systems are -really- finiky. =/

Mainly with the exectuable that alters the settings on my NIC which used to work in the Zenith. Never had that error before now its all I get. Any ideas how to remedy this?

Terry Yager
April 14th, 2004, 07:40 PM
Now a new problem suddenly manifested itself. I get an "internal stack overflow" and pairity errors when running large executable files. *sighs* 8088 systems are -really- finiky. =/

Yeah, and Zenith systems are even more so.


Mainly with the exectuable that alters the settings on my NIC which used to work in the Zenith. Never had that error before now its all I get. Any ideas how to remedy this?

I dunno, can you access the MFMxxxx monitor program? (Hold down the ESC key and power-on). That should bring up the monitor. Typing a ? will call up a menu of options. Use the B(oot) command to boot from the floppy or hard drive (the proper command syntax is on the help menu). Anyways, mebbe the EMM driver yr using is causing the problem, and using the Zenith one I sent ya may clear it up.

--T

Super-Slasher
April 15th, 2004, 06:28 AM
Nope, get the same problem even with the new EMM, although the computer seems to run a bit better with the Zenith one than the MS-DOS one. Still get that internal stack overflow, even with the EMM board removed, and I never used to get it before. The same program will work in all other computers as well.

Too bad I couldn't find drivers for the few 8-bit ethernet cards I have...

Terry Yager
April 15th, 2004, 06:55 AM
Nope, get the same problem even with the new EMM, although the computer seems to run a bit better with the Zenith one than the MS-DOS one. Still get that internal stack overflow, even with the EMM board removed, and I never used to get it before. The same program will work in all other computers as well.

Too bad I couldn't find drivers for the few 8-bit ethernet cards I have...

Have ya tried the Zenith OEM DOS I sent ya? Zeniths can be pretty picky about the software that they like and don't like. Best ta use a version of DOS that was specific for them.

--T

Super-Slasher
April 15th, 2004, 11:34 AM
I'll have to try later, then.

The DOS you sent me is only on one disk/one disk image? There's no other disks that go with it?

Super-Slasher
April 15th, 2004, 01:09 PM
I can't beable to use this image because I haven't got a single 360KB disk drive; all 1.2MB's, and they won't make the image correctly on 360KB disks, as you said.

:(

Super-Slasher
April 15th, 2004, 01:18 PM
And the program to configure the NIC still freezes with the new DOS, although it doesn't give me that stak overflow error.

You know what? I give up on this, finally. This machine is just too fussy for my likings.

I don't know what I'll do with it now, though. Might try selling it again, now that I know its proper model number/identification.

$1 or best offer, hehe.

Terry Yager
April 15th, 2004, 03:00 PM
I'll have to try later, then.

The DOS you sent me is only on one disk/one disk image? There's no other disks that go with it?

Well, originally it was a two-disk set, but I've long since lost track of the Supplemental Programs disk, so yah, ya only get the one disk.

--T

Micom 2000
May 8th, 2004, 02:48 PM
>>You need an Expanded Memory Manager program (which is specific to the hardware you have). I have a copy of the Zenith EMM, but it will only work on a board made by Zenith (is yours?). If ya need it, send me an email and I'll get a copy to ya (soon's I drag out my media-transfer machine and set it up. The prog is on a 5 1/4" disk).<<

I have a 161 ZFA which is a luggable with popup Fdds and one of my faves. A lovely machine if a bit heavy. Do you know if your EMM
might work on this model ? If so I would appreciate obtaining it.

I know what a pain it can be to have multiple requests for set-up
software. I seem to have the only archive of some old NEC LTs
which I downloaded from an Aussie NEC BBS site many moons ago
and continuously get requests. I usually fulfill them and even made a zip
file just so I wouldn't have to continually gather them up.

The board is a backplane and I have a Plus hardcard that I've been
intending to install so this would give me much needed incentive. After
many years of laboring to get my various "new finds" working, I've
"burnt out" the last few years and am only now getting back into it.

Thanks, Lawrence

Terry Yager
May 8th, 2004, 03:24 PM
I have a 161 ZFA which is a luggable with popup Fdds and one of my faves. A lovely machine if a bit heavy. Do you know if your EMM
might work on this model ? If so I would appreciate obtaining it.

Thanks, Lawrence

You're in luck, I still have the zipfile on my hard drive. PM me your email addy and I'll send it right along. The MSDOS image is a TeleDisk image, so you'll need to d/l a copy from www.gaby.de to extract the DOS image, if you so desire. As long as your EMM board is made by Zenith, the memory manager should work. It's actually a "leftover" from my Zenith 161, which I sold a few months back. I know what ya mean about the weight, mine tipped the scales at 44 lbs. shipping weight (cost $50.00 to ship it to Californie). It was by far the heaviest luggable I ever owned. Next, at 40 lbs. is my '386 luggable, but it's pretty ruggedized, so there is a good reason for the extra weight.
BTW, the Zenith OEM version of DOS 3.2 contains Zenith-specific hard drive utilities, but I don't know if they work with the +HardCard or not. IIRC, the +Card needs it's own proprietary utils to get it to work.

--T