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Tandy 2500 SX/20 and Tandy 4825 SX restoration thread

MindParadox said:
Umm, holy crap? I've been googling this stupid part number for like a week now and nothing :p thank you!
I'll post here if it works(and hey, apparently I'll have 8 of the durn things to get rid of, so if anyone needs a couple, lemme know, cheep! :p)
Click to expand...

Did they work?! I had been looking but sorta gave up.
 
MindParadox, did they work?

I've been looking too but was going to give up.
 
drall said:
MindParadox, did they work?

I've been looking too but was going to give up.
Click to expand...

Sorry for the triple post... :( I didn't realize the board was moderated and that posts took so long to appear.

I thought I did something wrong.
 
aSorry, been working this problem from a different angle. I didn't buy them, cause i thought i had a line on the exact parts, but i was wrong :p
 
I just dug out my old Tandy 4825 SX and want to max it out. Can anyone tell me what the largest hard drive this will support natively? Also could I use an AMD 5x86-P75 with it? There doesn’t seem to be a way to change the FSB from 25 to 33MHz, but I can’t remember if this vintage machine would just adjust automatically.

Thanks!
 
mikem said:
I just dug out my old Tandy 4825 SX and want to max it out. Can anyone tell me what the largest hard drive this will support natively? Also could I use an AMD 5x86-P75 with it? There doesn’t seem to be a way to change the FSB from 25 to 33MHz, but I can’t remember if this vintage machine would just adjust automatically.

Thanks!
Click to expand...

I have an 8GB in mine - with the XTIDE Bios on an ISA Ethernet card. Natively, you're going to be hard pressed to get more than a 500MB drive without the XTIDE BIOS controlling things.
 
acadiel said:
I have an 8GB in mine - with the XTIDE Bios on an ISA Ethernet card. Natively, you're going to be hard pressed to get more than a 500MB drive without the XTIDE BIOS controlling things.
Click to expand...

That’s what I figured. Thanks for replying!

BTW - do you have any idea if the bus speed will adjust to 33MHz (or can be adjusted) so I could use a DX/2 66 or one of those AMD 5x86-P75 chips? I found a document that seems to indicate it can do 25/33/50MHz FSB but no information on how to make it happen:

https://stason.org/TULARC/pc/motherboards/T/TANDY-RADIO-SHACK-486-4825-SX.html
 
acadiel said:
Instead of posting everywhere across here (and in the AHCS's Yahoo group), I figure I can leave this as my 'here's what I'm doing to fix these two systems up' thread.

Stay tuned as I reply to this thread and ask questions as I fix these up.

Recently acquired two Tandys that they must have made right before they quit making them. I already have a Tandy 1000 from my father in law as well as a Tandy 1000 RLX that I acquired a few months back.

Tandy 2500 SX/20 -
  • 386 SX/20
  • 2MB RAM (4 x 256K 30 pin SIMMs + 1MB onboard)
  • 80MB WD IDE drive (with issues)
  • 3.5" 1.44MB and 5.25" 1.2M floppy drives.
  • Built in Tandy audio (I think)
  • Built in VGA
  • Apparently a standard PS/2 keyboard and mouse connection (unlike the RLX)
  • No software loaded. Drive was empty, but I did find it's "Setup" program.

Plans:
  • Up RAM to 5MB (max onboard) - 4 x 1M 30 pin SIMMS + 1M onboard (These are on the way from a friend)
  • Add extra video DRAM chips.
  • Repair or replace hard drive with another solution (i.e. disk on chip or Compact Flash, or XT IDE card with Compact Flash). (Trying a 256MB DOC from eBay)
  • Possibly replace 5.25" drive with IDE CDROM drive.
  • Figure out Tandy sound and/or add a ISA Soundblaster.

Tandy 4825 SX-
  • 486 SX/25
  • 5MB RAM (4 x 1M 30 pin SIMMs + 1MB onboard), 4 empty sockets
  • ?? IDE drive
  • 3.5" 1.44MB drive. 5.25" bay is empty.
  • No Built in audio
  • Built in VGA
  • Apparently a standard PS/2 keyboard and mouse connection (unlike the RLX)
  • Windows 3.x loaded. I found the 4825SX program on the net for it.

Plans:
  • Up RAM to 32MB (eight x 4MB 30 pin SIMMs).
  • Add extra video DRAM chips.
  • Repair or replace hard drive with another solution (i.e. disk on chip or Compact Flash, or XT IDE card with Compact Flash).
  • 5.25" bay with IDE CDROM drive. (I have a 40x CDRW drive I will attempt to put in here.)
  • Add 16 Bit Soundblaster (I have a SB16 Value laying around.)
  • Add Ethernet (I have an 8 Bit 3COM card laying around.)
  • Back up the stuff on the internal drive
Click to expand...

I was hoping you could give some more information on the ram for the 2500 sx/20

Not a lot of spare money during the pandemic so I don't want to buy the wrong ram.
Is it parity? Non parity? I know there's 9 chips on the ram, and it's 30 pin right?

I really want to restore this computer, the Tandy 2500 sx/20 was such a great computer, it deserves to run fully. But it keeps running out of ram because it only has the onboard 1MB keeping it going
(which doesn't play Kings Quest V very well when it crashes! Lol)

Thanks in advanced!
-David
 
I am rebuilding a Tandy 2500 SX/25. Did you guys use parity or non parity ram? And would either one work?
 
Dav9834 said:
I was hoping you could give some more information on the ram for the 2500 sx/20

Not a lot of spare money during the pandemic so I don't want to buy the wrong ram.
Is it parity? Non parity? I know there's 9 chips on the ram, and it's 30 pin right?

I really want to restore this computer, the Tandy 2500 sx/20 was such a great computer, it deserves to run fully. But it keeps running out of ram because it only has the onboard 1MB keeping it going
(which doesn't play Kings Quest V very well when it crashes! Lol)

Thanks in advanced!
-David
Click to expand...
Hey David, I used this ram... https://www.ebay.com/itm/1650350751...7pJTMJ6SWe&var=&widget_ver=artemis&media=COPY

And this for video RAM as stated in a previous post. Both confirmed working in my 2500/sx 25

MT4C1664Z-10 Price - MT4C1664Z-10 in stock - Buy MT4C1664Z-10 on Utsource.net

MT4C1664Z-10 is a 4Mbit (512K x 8-bit) CMOS Static RAM manufactured by Micron Technology. It is a low-power device that operates from a single 2.7V to 3.6V power sup
www.utsource.net

I bought them from that link and had no problems with them.

I also have all the original disks, manuals, and paperwork if anybody needs to see them or anything just let me know.
 
c64manguy said:
Hey David, I used this ram... https://www.ebay.com/itm/1650350751...7pJTMJ6SWe&var=&widget_ver=artemis&media=COPY

And this for video RAM as stated in a previous post. Both confirmed working in my 2500/sx 25

MT4C1664Z-10 Price - MT4C1664Z-10 in stock - Buy MT4C1664Z-10 on Utsource.net

MT4C1664Z-10 is a 4Mbit (512K x 8-bit) CMOS Static RAM manufactured by Micron Technology. It is a low-power device that operates from a single 2.7V to 3.6V power sup
www.utsource.net

I bought them from that link and had no problems with them.

I also have all the original disks, manuals, and paperwork if anybody needs to see them or anything just let me know.
Click to expand...
Hey c64manguy - do you have images of all the original disks? Is there any way you can upload them to archive.org? It's be great to have all the OEM images somewhere.
 
acadiel said:
Hey c64manguy - do you have images of all the original disks? Is there any way you can upload them to archive.org? It's be great to have all the OEM images somewhere.
Click to expand...
Hey. I don't have images. I'll look into a way to get them imaged. I don't have a grease weasel but I have a win98 machine with a disk drive. I'll let you know when I put them on there.
 
c64manguy said:
Hey. I don't have images. I'll look into a way to get them imaged. I don't have a grease weasel but I have a win98 machine with a disk drive. I'll let you know when I put them on there.
Click to expand...
Sorry for the kinda-necro-post, but I've been looking everywhere for a set of sx20 setup disks. I found on "oldskool" the setupsx.exe file needed to access the bios, but it sure would be nice to restore that machine to factory settings.
 
eBayShippingGouger said:
Sorry for the kinda-necro-post, but I've been looking everywhere for a set of sx20 setup disks. I found on "oldskool" the setupsx.exe file needed to access the bios, but it sure would be nice to restore that machine to factory settings.
Click to expand...
Hey. No problem. I'll image them tomorrow afternoon. I'll post the link.
 
c64manguy said:
Hey. No problem. I'll image them tomorrow afternoon. I'll post the link.
Click to expand...
You're a lifesaver. About 30 years ago the disks simply disappeared and I remember trying to get replacement disks from Radio Shack so the "Tandy Sound" would work in Civilization 1. Turns out all these years later I find out that had nothing to do with it!
 
eBayShippingGouger said:
You're a lifesaver. About 30 years ago the disks simply disappeared and I remember trying to get replacement disks from Radio Shack so the "Tandy Sound" would work in Civilization 1. Turns out all these years later I find out that had nothing to do with it!
Click to expand...
archive.org

Tandy 2500SX/25 Factory Disk Images : Brandon Harmony : Free Download, Borrow, and Streaming : Internet Archive

Original disk images for the Tandy 2500SX/25 PC compatible. Disk 5 of the Windows 3_1 disk has 1 corrupted sector that I couldn't get to read and MSDOS 5.0...
archive.org

There ya go! I got everything I could. One disk had a bad sector and one was completely unreadable. But the audio drivers are in there.
 
c64manguy said:
archive.org

Tandy 2500SX/25 Factory Disk Images : Brandon Harmony : Free Download, Borrow, and Streaming : Internet Archive

Original disk images for the Tandy 2500SX/25 PC compatible. Disk 5 of the Windows 3_1 disk has 1 corrupted sector that I couldn't get to read and MSDOS 5.0...
archive.org

There ya go! I got everything I could. One disk had a bad sector and one was completely unreadable. But the audio drivers are in there.
Click to expand...
eBayShippingGouger said:
You're a lifesaver. About 30 years ago the disks simply disappeared and I remember trying to get replacement disks from Radio Shack so the "Tandy Sound" would work in Civilization 1. Turns out all these years later I find out that had nothing to do with it!
Click to expand...
archive.org/details/tandy-2500-sx-25
 
c64manguy said:
archive.org

Tandy 2500SX/25 Factory Disk Images : Brandon Harmony : Free Download, Borrow, and Streaming : Internet Archive

Original disk images for the Tandy 2500SX/25 PC compatible. Disk 5 of the Windows 3_1 disk has 1 corrupted sector that I couldn't get to read and MSDOS 5.0...
archive.org

There ya go! I got everything I could. One disk had a bad sector and one was completely unreadable. But the audio drivers are in there.
Click to expand...

Downloading now, thank you! I'll see how it works on my sx/20

edit: This should be interesting, I believe the SX/25 has the same Western Digital Paradise 256kb VGA video card as the SX/20, let's see what they do.
 
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