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1000SX 3.5" Floppy

Agent Orange

Agent Orange

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I'm having a problem reading any 720 KB floppy with my 1.44MB drive. I'm running MS-DOS 3.3. As far as I can tell, the Tandy 1000SX BIOS doesn't
support DRIVPARM. What I did was find a way to edit DRIVPARM using DEBUG. The results are that the BIOS will now recognize DRIVPARM. This is accomplished by adding a 2nd "D" to the command line; i.e., DRIVPARM=/d:1 /c /h:2 /s:9 /t:80 is now DRIVPARM=/dd:1 /c /h:2 /s:9 /t:80. This command is supposed to configure the floppy drive for a 720KB floppy disc.
Well, it does, I guess. Our new Vintage XT-IDE controller see it okay along with the 5.25 360KB floppy drive. What am I doing wrong? BTW, if I use DRIVER.SYS instead of DRIVPARM, same results. I beeen through the cabling, used standard Tandy flat cable as well as "twisted" cable. I'm attempting to set the 3.5" floppy drive as "A" and the 5.25 Floppy drive as "B". What I'm seeing is "SEEK" errors. Any help would be appreciated. I've changed out the floppy drives and the cabling, so I don't suspect that the problem is there.
 
Are you using DS/DD media or DS/HD media? If you're using DS/HD media, make sure you cover the media sense hole. Some drives just don't handle this situation properly.

Better yet, bypass the media sense circuit on the drive itself. If it uses optical, you can disconnect one leg of the sensor. If it uses a microswitch (did any?) you can disconnect one pole from the switch.
 
Using old-time 720KB 3.5" floppys. I had several boxes of them laying around (who knows why?). I remember buying a heavy duty punch for about $20 that would create the hole that you would need to format them to 1.44MB back in the day.:sarcasm:
 
The Tandy 1000SX 3.5" Floppy Fix

The Tandy 1000SX 3.5" Floppy Fix

. . . or confessions of a Tandy junkie -

There is no fix. It was never broke to start with. For my part, I jumped to a conclusion that it was going take some sort weird mojo to get a 3.5" floppy to work on the 1000SX. I fussed endlessly with "DRIVER.SYS" and even went
so far as to "DEBUG" "DRIVPARM" so it would work with MS-DOS 3.3.

The main problem was the floppy cable. I used the standard floppy cable with the familiar twist. In utter frustration, I tore apart a perfectly good 3.5" floppy, normally hard wired to DS1 and rewired it for DS0. It looked like it was going to fly there for a while. Both 5.25 and 3.5 activity lights would come on at the same time and you would get a "SEEK" error on 3.5 drive.

By chance, and as a last resort, I sliced the the cable twist in two with my dikes and soldered it back up so it would be a "straight through" cable, 7 wires in all. It worked flawlessly. (Don't know what happened to the original dual floppy, cable - haven't seen that since I installed the ST-225 back in 1987). The Tandy 5.25" TEAC standard issue floppy was jumpered to DS0, thereby designating it as the "A" drive, while the default for the 1.44 MB garden variety 3.5" floppy drive is set in stone to DS1.

As far as the 1000SX BIOS is concerned, it needed neither "DRIVER.SYS" or "DRIVPARM' in the "CONFIG.SYS". It works like it had the two original 5.25" drives installed. When formating a 720 KB disk in the 1.44 MB 3.5" floppy, I observed that there was no need to invoke "FORMAT B: /720" (again, that might be a passing reference the DOS under Xp, not sure). The Tandy BIOS seems to sort it all out.

As an added bonus, my 1000SX has a "beta" VC Forum XT-IDE controller, what a sweetheart that card is (Thanks Lynch/Hargle/Per and all the rest that had a hand in that). The XT-IDE lets me boot the hard drive as well as either floppy. How sweet is that!

The bottom line is that the 3.5" floppy works and is probably the easiest upgrade you'll ever make on 1000SX.

A closing note: Checks good with TANDY OEM MS-DOS 3.2 & MS-DOS 3.3. Also, if you desire to make the 3.5" floppy the "A" drive you will have to tear it down move the solder jumper from DS1 to DS0 as well as jumpering the 5.25" floppy to DS1.
 
Interesting! It got me thinking about one of my boxes..

Would you wager that (or do you know if) the straight-through floppy cable is required on other Tandy 1000 series models? My Tandy is a 1000 RL/HD, so it doesn't have 5.25" bays (tiny little bugger..), but I seem to recall trying to add a 1.44MB floppy at one point or another, and losing my mind. That could either be due to the lack of support in the BIOS, which I chocked it up to then, or the newly raised floppy cable possibility. I learned a lot since I got this Tandy and one of the things I learned is that the 1.44MB floppy standard dates to (iirc) 1987, while this machine is (again, iirc) 1990 - that means that in all likelyhood it should support 1.44MB floppy drives. The only reason it has the 720K drive, in this case, was because it was a budget machine (also the reason it has an 8086 processor at 10mhz [on the goddamn tiniest board you've ever seen from then, makes a microATX look huge], even though it was 1990).

As a sidenote, my RL/HD has a flawlessly working XTIDE aka 8-bit IDE HDD in it - works great too. I didn't realize this when I got it. :)
 
Raven:

I think the easiest way to check that out would be to install one only 3.5" floppy and make sure you connect below the twist. If it runs, all is well. If not, I would then try to setup "DRIVER.SYS" and invoke the following to the
"CONFIG.SYS" - (device=c:\dos\driver.sys /d:0 /f:2 /c) the d makes it the
"A" drive and the F:2 tells the BIOS that you have a 1.44 MB that needs to
setup as 720 KB. I'll take that bet (real cold beer) that it'll work. I'm now more or less convinced that you'll need a straight through cable on any 1000.
The HD may be a different story, because I believe the BIOS maybe slightly different (lacking). If you find that you need to use "DRIVER.SYS", it will indicate that drive is "external", and come up as "E:\", assuming that you have a hard drive also. If that scenario works, you can make that floppy E think it's the "A" drive by using "ASSIGN A=E" in the "AUTOEXEC.BAT" (no colons). I doubt that it will get to that, it'll work with the flat cable.
 
Thanks for the detailed suggestion! I will, at some point this weekend, try it out and let you guys know. Maybe we can start a record of some kind as to which 1000 models this works on until we can confidently say it works for all, and then stick it in a wiki someplace. :p

Agent Orange said:
Raven:

I think the easiest way to check that out would be to install one only 3.5" floppy and make sure you connect below the twist. If it runs, all is well. If not, I would then try to setup "DRIVER.SYS" and invoke the following to the
"CONFIG.SYS" - (device=c:\dos\driver.sys /d:0 /f:2 /c) the d makes it the
"A" drive and the F:2 tells the BIOS that you have a 1.44 MB that needs to
setup as 720 KB. I'll take that bet (real cold beer) that it'll work. I'm now more or less convinced that you'll need a straight through cable on any 1000.
The HD may be a different story, because I believe the BIOS maybe slightly different (lacking). If you find that you need to use "DRIVER.SYS", it will indicate that drive is "external", and come up as "E:\", assuming that you have a hard drive also. If that scenario works, you can make that floppy E think it's the "A" drive by using "ASSIGN A=E" in the "AUTOEXEC.BAT" (no colons). I doubt that it will get to that, it'll work with the flat cable.
Click to expand...

Edit: 444 posts, interesting. I'm probably going to hit 486 in the next day or two - that'll be fun.
 
The Tandy 1000RL does not support HD drives. The floppy controller is DD only. Further, all Tandy 1000 3.5" floppies, HD and DD are special in that they have no power connector, receiving power through the data cable. You can adapt a regular floppy to work, but it requires a bit of work. Also, all Tandy 1000s use straight floppy cables, 5.25" and 3.5". HD Support did not come to the Tandy 1000 serious until the 1000 RLX and RSX, which both also have VGA graphics.

The Tandy 1000 FAQ goes over all this, which you can read here, or the floppy section specifically.

I know that's probably not what you wanted to hear, but I don't like it either heh :rolleyes:

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Trevor
 
Yeah I seem to recall the whole single-connector deal now. I am disappointed that the BIOS doesn't support HD floppy drives though. Not a huge deal though - I can always install an external ZIP disk drive on Parallel and xfer 100MB at a time to it. :D

*loves zip disks*

Also, if I can find a card that is a RAM expansion AND floppy controller I could hook it up to that.. Dunno if those exist.
 
Hate to burst another bubble, but most T1000s parallel ports are nerfed as well, being unidirectional. Parallel zips will not work with any of the internal parallel ports for any Tandy 1000 before the RLX. Of course you are free to install a parallel card in an ISA slot, but on your RL, that would be the only card.

In the case of the RL, a parallel card is probably the single most useful card, at least as far as expansion capability. The are parallel ZIP drive, CDROMs, HDs (IDE and SCSI), floppies (including HD), ethernet... just about everything. Since the RL has decent sound and reasonable video already, and it's greatest shortcomings are storage capacity and connectivity, parallel seems to be the way to go, for me at least, with my 2 RLs ;)

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Trevor
 
Lord Moz,

I hear you on the RL. I drew the line a long time ago about what I was going
to get into. Back in 1986 I could afford the 1000SX but not the XT. The XT's were going for about $1700 and up at the time. It seemed, though, that there was something out there for every interest.

Let me try to clarify one point. I am not trying to adapt an HD drive to the
Tandy 1000SX or and other Tandy. My sole interest was to get the 1.44 MB
3.5" floppy to work on the 1000SX as a 720 KB floppy and now it does. I feel like was reinventing the wheel there for a while. It's all in the cabling, you know.

One word about those HD drives. If Hargle has his way (and he will), he's
likely to have the "mother of all XT controllers" out there on the horizon. Think about the possibilites of one 8-bit XT IDE/hd floppy/parallel/serial card. Wouldn't need to give that expansion chassis another thought.
 
In my T130B thread in Hardware Support, I've been working with lots of drivers getting an HD into my XT. The XT's 360KB floppies don't fit many drivers and utilities, so I stuck an HD 3.5" floppy on its original IBM floppy controller and used it at 720KB for testing purposes. After the HD is working I will probably return it to its 2x 360KB drive config, as appearance was a large part of the reason I used a full height drive on it.

Running MSDOS 6.22 required no changes at all. Just connected the drive and it booted a 720KB dos boot disk no problems right from the start.

I wasn't sure if it was going to like the 80 tracks or not, but I'm happy it does :D

The Tandy 1000RL was my first "PC" when my father got it when I was ~11-12 years old.
We had been using a Color Computer 3 for several years before that.

As many other people here, I've been rebuilding a collection of all the computers I had growing up, along with all the machines I wanted but couldn't have. Just a few days ago I finally purchased a DEC AlphaPC 164 board from eBay to have a "real" Alpha system in my collection. (I say real, because my Multia is pretty puny ;) )

I've been really looking for a Tandy 1000 RSX, but haven't seen any, at any price.

I too am anxiously waiting for the new XTIDE boards... I love the smell of solder and burning rosin!
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Trevor
 
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Problem is I don't have a CGA monitor to use with it yet, so my single slot is taken up by a VGA card. I think I'm getting a CM-4 from Kelly in late January though, so then I can look at expanding - but my plans were to use a RAM expansion. Perhaps I'll look for one with a parallel port - they're out there, right?

Lord Moz said:
Hate to burst another bubble, but most T1000s parallel ports are nerfed as well, being unidirectional. Parallel zips will not work with any of the internal parallel ports for any Tandy 1000 before the RLX. Of course you are free to install a parallel card in an ISA slot, but on your RL, that would be the only card.

In the case of the RL, a parallel card is probably the single most useful card, at least as far as expansion capability. The are parallel ZIP drive, CDROMs, HDs (IDE and SCSI), floppies (including HD), ethernet... just about everything. Since the RL has decent sound and reasonable video already, and it's greatest shortcomings are storage capacity and connectivity, parallel seems to be the way to go, for me at least, with my 2 RLs ;)

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Trevor
Click to expand...
 
I will order at least 10 of those, if they get made. Throw in a 10mbit ethernet jack too while we're in the dreamish planning stages of that design - it'd be nice.

Agent Orange said:
Lord Moz,

I hear you on the RL. I drew the line a long time ago about what I was going
to get into. Back in 1986 I could afford the 1000SX but not the XT. The XT's were going for about $1700 and up at the time. It seemed, though, that there was something out there for every interest.

Let me try to clarify one point. I am not trying to adapt an HD drive to the
Tandy 1000SX or and other Tandy. My sole interest was to get the 1.44 MB
3.5" floppy to work on the 1000SX as a 720 KB floppy and now it does. I feel like was reinventing the wheel there for a while. It's all in the cabling, you know.

One word about those HD drives. If Hargle has his way (and he will), he's
likely to have the "mother of all XT controllers" out there on the horizon. Think about the possibilites of one 8-bit XT IDE/hd floppy/parallel/serial card. Wouldn't need to give that expansion chassis another thought.
Click to expand...
 
I'm pretty sure these could be made to work with a packet driver of some sort...

I bought 4 a while back and had played with them, but got distracted before I got them to really work for me. Essentially they work like a modem on ethernet. They accept AT commands at the serial port, and will open a TCP stream to an IP or domain name specified on the ATDT line in your dial script. My thoughts are you could then connect to another machine running PPP/SLIP on a PTY and then run a PPP/SLIP packet driver on the Tandy. Obviously this wouldn't get you full 10Mbit ethernet speeds, but it frees you from serial cables or real modems. Also, some addon serial/parallel cards can support very highspeed serial links, and I believe these UDS-10 devices can connect at just under 1Mbp/s on the serial link.

I've been trying to find ways around my RLs limitations for quite some time :p

Also, what are you planning to do with your memory expansion? The RL would only support EMS ram, and the number of programs that will run on the RL that would use EMS isn't large. Also, I haven't seen many EMS cards that will fit inside the RL, as it is limited to cards less than 10" in length. I bought an AST Rampage for my TL/2 since it has plenty of slots, but it won't fit it it either :(

There are some software device drivers that will emulate EMS with a swap file on a hard drive... obviously much much slower than RAM, but it would allow those programs to run. If you put an XTIDE in your machine and used a compact flash card, it might even pass for slow ram then :p

Tandy built very specialized machine aimed at particular markets. As much as I love mine, I have had to come to terms with their limits. I haven't given up trying to expand them, but I have had to be a bit more creative.

As far as a monitor, try to get a CM-11, I don't know if you will be satisfied with a CM-4, which is an older CM-5, and they are known for being among the worst CGA monitors around. The CM-11 is a first rate CGA monitor though.

Good luck to you though.
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Trevor
 
I've heard that if you expand it to 768K it uses 128K for the video, but afaik there's no documentation on expanding it further than that.. who knows. :p
 
Raven said:
I've heard that if you expand it to 768K it uses 128K for the video, but afaik there's no documentation on expanding it further than that.. who knows. :p
Click to expand...

Yes. Due to the way Tandy graphics work, your current video mode affects how much free memory you have for your current program. Much like integrated video on modern laptops with "shared" memory. You may have noticed text on older DOS games that list their minimum RAM requirements as 512KB, 640KB for Tandy, and this is why. Upgrading to 768KB actually gives you more memory than any of the Tandy video modes requires, and in fact allows a few more modes, but these modes were never supported in bios and were not used very often. I think you can find a few examples of some of those programs at Tvdog's Tandy 1000 archive. I've seen a program that says it can transfer some of that memory from video to dos, but haven't used it. That would certainly be handy at times.

768KB is as far as it is designed to be upgraded on the system board. Any other memory would have to be on the ISA bus, or some much much more creative attachment... processor director or something, but that would require some pretty extensive engineering skills ;)

If you are a Tandy fan, you really owe it to yourself to explore his site thoroughly.

__
Trevor
 
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