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PS1
March 19th, 2004, 06:27 PM
Can i get it to use a 1.44 floppy drive if so how do i go about it?

thanks.

Terry Yager
March 19th, 2004, 07:21 PM
Can i get it to use a 1.44 floppy drive if so how do i go about it?

thanks.

A long time ago, I used to have a special kind of floppy controler made by DTK, which allowed up to 4 drives of assorted capacities, and worked in PC-XT class machines, via a bios extender chip on board. Short of finding one of those cards (or similar), you won't be able to get the HighDensity drive to work in an 8086 machine, except as a 720K drive. (That's the highest capacity your bios will support).

--T

CP/M User
March 19th, 2004, 08:05 PM
"Terry Yager" wrote:

> Can i get it to use a 1.44 floppy drive
> if so how do i go about it?

> A long time ago, I used to have a
> special kind of floppy controler made
> by DTK, which allowed up to 4 drives
> of assorted capacities, and worked in
> PC-XT class machines, via a bios
> extender chip on board. Short of
> finding one of those cards (or similar),
> you won't be able to get the HighDensity
> drive to work in an 8086 machine,
> except as a 720K drive. (That's the
> highest capacity your bios will support).

I was just wonderning if this was an IBM
Compatable machine, because the XTs
were 8088 based (same as with the IBM
personal computer). Couse that doesn't
mean that it doesn't run DOS, but DOS
did exist for those other machines which
weren't quite IBM based. If it's not fully
IBM compatable connecting up a
card may issue a problem.

Cause if you know if it's passed the test
with some graphical stuff, then finding a
drive card wouldn't be an issue at all. And
there would be a few around (I think)
which would support 1.44Mb disk drives
it's just a question of finding one.

If not, then maybe try asking around to
see who knows of any of those cards.

Cheers,
CP/M User.

Terry Yager
March 19th, 2004, 08:22 PM
I was just wonderning if this was an IBM
Compatable machine, because the XTs
were 8088 based (same as with the IBM
personal computer). Couse that doesn't
mean that it doesn't run DOS, but DOS
did exist for those other machines which
weren't quite IBM based. If it's not fully
IBM compatable connecting up a
card may issue a problem.

Yes. The Compaq Deskpro was considered 100% IBM compatable. In fact, Compaqs have always been considered to be among the most compatable machines ever. The only wierdness I rem'br 'bout the original Deskpro was that it had a strange (proprietary) video connector on the back, next to the P.S., which is a kinda round plug and supported a Compaq (TTL Monochrome) display. This connector can be switched out and a "regular" video card installed instead, if desired.


Cause if you know if it's passed the test
with some graphical stuff, then finding a
drive card wouldn't be an issue at all. And
there would be a few around (I think)
which would support 1.44Mb disk drives
it's just a question of finding one.

If not, then maybe try asking around to
see who knows of any of those cards.

Cheers,
CP/M User

That DTK card was nice, I wish I had saved one of 'em. (Actually, at one time I had two of 'em). Other companies (besides DTK) made similar cards, the important thing is that it needs an on-board bios to use it in an XT-class machine (for HD).

--T

CP/M User
March 19th, 2004, 11:24 PM
"Terry Yager" wrote:

> Yes. The Compaq Deskpro was
> considered 100% IBM compatable.
> In fact, Compaqs have always
> been considered to be among the
> most compatable machines ever.
> The only wierdness I rem'br 'bout
> the original Deskpro was that it
> had a strange (proprietary) video
> connector on the back, next to the
> P.S., which is a kinda round plug
> and supported a Compaq (TTL
> Monochrome) display. This
> connector can be switched out and
> a "regular" video card installed
> instead, if desired.

Okay, but it was an 8086 wasn't it?

> That DTK card was nice, I wish
> I had saved one of 'em.
> (Actually, at one time I had two
> of 'em). Other companies (
> besides DTK) made similar cards,
> the important thing is that it needs
> an on-board bios to use it in an
> XT-class machine (for HD).

Actually, I thought this was standard
to have BIOS on those Input/Output
cards. By floppy controller for my
XT has a set of DIP switches, though
it doesn't support 1.44" Floppies, just
360k, 720k & 1.2Mb I think!

PS1
March 20th, 2004, 05:07 AM
i changed the video card on it its running a colour card.

original card went up in smoke when i first switched it on must have had a short luckily no damage was done to the machine.

it has a 20mb hard drive fitted with some weird software must boot it up at some point see if any of you know of the software.

i did try it with a floppy drive light came on but it wont read.

wess r daniels
July 6th, 2005, 07:56 PM
Deskpros are 8086 and very close or better to AT 286.
The 1.44 doesn't NOT need a new controller in every case...
DOS 5 has drvparm and loading that command with the right switches will
give you the 1.44 capacity.

But this depends on the drive hooking up electrically....not always gonna
happen, and that's when you'll need a controller card...
The cards are still out there, I might have one....
8bit cards....I but one in my 10mhz xt.....

Chris2005
July 28th, 2005, 12:07 AM
the 8086 is just the an 8088 with a 16 bit data bus (the 8088 had an 8 bitter). There's nothing that makes the 8086 incompatible in anyway. Same exact instruction set. Same goes for the 80186/80188. Most of the computers that used the 80186 were "semi-compatibles" - Tandy 2000, Mindset, a few others, but that's not due to the use of the chip. Most people assume that. The AT & T 6300 (also marketed under Olivetti and Xerox names) used the 8086, and was "pretty" compatible. There were others. There was one other difference, the 8086 had a 6 byte instruction queue, the 8088 4. Just made the 8086 a bit quicker there.
In those days, as long as the designers held to certain guidelines when designing the boards, the thing to look for when shopping for compatibility was the bios maker. Phoenix was the name to go with. Some name brand puters had Phoenix bios', as well as no-name clones.

Chris2005
August 4th, 2005, 12:26 AM
the reality is you can use 1.44 meg drives in a stock Deskpro 8086 - just that they'll only work as if they were 720k drives. Supposedly you have to use actual double density 3.5" floppies, but I've heard reports to the contrary. Look at micro-zone.com. It's a PCjr site, but that mod is useful for any PC/XT class machine. A very useful situation for peeps using old puters, since 5.25" disks are nowhere to be found.
By the way, I want a Compaq deskpro in the worst way :(.

Terry Yager
August 4th, 2005, 03:22 PM
Chris,

Pm me...I got one...

--T

MystikShadows
August 4th, 2005, 04:56 PM
Yeah you can get a HD 3 1/2 disk, put some tape on the whole that doesn't close and it will be recognized as a genuine 720Kb :-) I used to do it all the time.

Terry Yager
August 4th, 2005, 05:28 PM
Yeah you can get a HD 3 1/2 disk, put some tape on the whole that doesn't close and it will be recognized as a genuine 720Kb :-) I used to do it all the time.

Even without taping over the hole, the drive should format a HD disk to 720Kb. There is no sensor on a 720Kb drive to detect if the hole is there or not...without the sensor, it autmatically sees it as DD (cause how does it even know enough to look for the hole if there is no switch there?).

--T

Chris2005
August 4th, 2005, 06:13 PM
right, but we're talking about using a HD 3.5" drive as a 720k drive. You're supposed to use real 720k disks, but I hear that people use 1.44 meggers and perhaps even work better. The drive has some kind of intelligence apart from the controller supposedly, and it's been said some won't format a 1.44 meg disk to 720k. Something like that. See micro-zone.com. Interesting notes there and in the forums.

Terry Yager
August 4th, 2005, 06:37 PM
I dunno, I've never run into that problem. I just use the "F" switch with FORMAT.COM and it's always worked for me. I have run into lots of troubles trying to format 360Kb disks with a 1.2Mb HD 5.25" drive though...it don't work worth a damn (because of the different speed?).

--T

Mad-Mike
August 4th, 2005, 10:35 PM
The 8086 most likely won't work with a 1.44M Floppy since it was released before those were ever on the drawing board, unless it uses a later Compaq BIOS (1987<), I have no idea when Compaq nixed them from their product line. The 286/12 and 386/16, 386/20, and 386/25 all used the same 1987-88 BIOS and could use 1.44M floppy drives, that I know for sure. I think I have seen a Deskpro 8086 running a 3.5" Floppy Drive on the original controller before on E-bay, but it may have been 720K. You will need the Setup Utility Diskette to set it up, and even then, I have had trouble getting 1.44M drives to work on my Deskpro 286 when the motherboard was till good.

As for the video jack in back, that's just the power connector. The original Compaq monitors had a DIN-3 pin plug that plugged into the little round connector next to the power supply for power if I'm not mistaken, I know that's how it was on my Deskpro 286 and 386. The monitor uses a standard 9-pin video connection, and is compatible with Monochrome, CGA, and EGA graphics modes shockingly enough (though on some higher resolution EGA modes, the screen goes a little off center). I was insane enough to try it out with the Deskpro 386 (insane being the idea of actually USING an early 8086 mono monitor on a 386 with EGA), using the original Quadram EGA card it shipped with (I've seen at least 4 of these on E-bay from the back to know)