VOGONS


Toshiba T5200 mods and upgrades

Topic actions

Reply 60 of 534, by IanB

User metadata
Rank Member
Rank
Member

As promised, here are some details on CPU upgrades:

There are four possible 486 compatible CPUs from Cyrix / Texas instruments that can be used to upgrade the T5200's Intel 386 processor (Texas Instruments made the CPUs for Cyrix and sold them under their own brand as well):

upgrades.jpg
Filename
upgrades.jpg
File size
905.73 KiB
Views
1774 views
File license
Fair use/fair dealing exception

CX486DLC / TX486DLC The Cyrix or Texas Instruments DLC upgrade. It was available in a variety of speed grades, e.g. 20, 25, 33 & 40 Mhz and has 1KB of cache that requires hardware modifications to fully support the cache. Any of those speeds should work on the T5200 but will only run at 20Mhz

CX486DRx2 This is the retail upgrade made by Cyrix and has clock doubling built in. It was available in various speed grades, 16/32, 20/40 & 33/66 etc. so when run on a 16 Mhz bus you get 32Mhz CPU, on a 20Mhz bus you get 40Mhz CPU and on a 33Mhz bus you get 66Mhz CPU etc. This also has 1KB of cache and has special circuitry built in so that no hardware modifications are necessary to support the cache. You would need a minimum of 20/40 to run on a T5200

TX486SXLB-040S-GA This is the ultimate upgrade and is a version of the DLC processor made by TI that has 8KB of cache instead of 1KB. It also has a clock doubling setting so can either be run at full 40Mhz on a 40Mhz bus or run at 40Mhz on a 20Mhz bus (the latter is suitable for the T5200) To get the best out of this chip you have to do the hardware mods, but even without them it still outperforms the DLC chip and gives similar performance to the CX486DRx2.

TX486SXL2B-050S-GA which is similar to the above but rated for 25/50Mhz and would also work on the T5200 but only run at the same speed as the above (20/40)

Note these last two part numbers have to be exact as one different letter or number means a different version. e.g. without the second "S" you get them in a 486 pinout instead of a 386 pinout. Unfortunately TI didn't print the full part number on the chip so you might have to confirm that you are buying the right version visually by checking the package and number of pins (386 size PGA 132 which has 14 pins on a side, not 486 size PGA 168 which has 17 pins on a side:

sizes.jpg
Filename
sizes.jpg
File size
897.63 KiB
Views
1774 views
File license
Fair use/fair dealing exception
pins.jpg
Filename
pins.jpg
File size
994.73 KiB
Views
1774 views
File license
Fair use/fair dealing exception

Here are some comparisons using the DOOM timedemo benchmark "doom -timedemo demo2". This doesn't necessarily show the best results for the faster CPUs as it is limited by the speed of the screen and more CPU bound tasks would likely show different results but it should give a rough idea of relative performance.

80386 @ 20 Mhz
44044 realticks

CX486DLC @ 20Mhz no hardware mods
20583 realticks

CX486DLC @ 20Mhz with flush and a20 mods
19866 realticks

CX486DRx2 @ 40Mhz (clock doubled) no hardware mods
16245 realticks

CX486DRx2 @ 40Mhz (clock doubled) with flush and a20 mods
16204 realticks

TX486SXLB-040S-GA @ 40Mhz (clock doubled) no hardware mods
16963 realticks

TX486SXLB-040S-GA @ 40Mhz (clock doubled) with flush and a20 mods
14122 realticks

The TX486SXL2B-050S-GA will perform identically to the TX486SXLB-040S-GA and as you can see from the above, the hardware mods only really benefit those processors but even without them they are still better than the DLC.

These processors run quite hot so it would probably a good idea to stick a low profile heatsink on them although they should work OK without one.

My patched BIOS detects and configures all the above automatically and will also detect if the hardware mods have been made and configure them to make use of the mods. (I'll describe the mods in a later post.)

I've updated the BIOS patches to V1.2 and posted new versions at the bottom of the first page of this thread:
Toshiba T5200 mods and upgrades

Last edited by IanB on 2018-02-27, 01:21. Edited 1 time in total.

Reply 62 of 534, by kultakala

User metadata
Rank Newbie
Rank
Newbie

Okay, finally i made it... the floppy is working 😀
Many thanks to IanB!

I was a little bit confused as the header pin numbers and the layout of the floppy connector on my mitsumi drive did not match, but now its working.
I had to make it the other way around.

As IanB suggested i made a bios and vga dump... its from my newer board.

Filename
Dumps.zip
File size
13.54 KiB
Downloads
78 downloads
File comment
Bios and VGA Dump
File license
Fair use/fair dealing exception

Reply 63 of 534, by IanB

User metadata
Rank Member
Rank
Member
kultakala wrote:

As IanB suggested i made a bios and vga dump... its from my newer board.

Thanks for the BIOS dumps, the VGA one was OK and the same as one we already have but the main BIOS is blank except for 256 bytes at the end.
I think this might be due to some memory manager software interfering with the dump.
Did you boot from a clean floppy copy of DOS with no autoexec.bat or config.sys files?
If not, can you try to dump it again that way.

Reply 64 of 534, by kultakala

User metadata
Rank Newbie
Rank
Newbie

I did start from a dos floppy but it was version 4.01... i would say there was no memory manager.
But i did the bios dump again, with a dos 6.22 floppy with nothing on it but the command.com, bios.exe and debug.exe.

Here is the new dump:

Filename
BIOS.zip
File size
502 Bytes
Downloads
61 downloads
File comment
New Dump
File license
Fair use/fair dealing exception

One question... i have a 100MB Conner disk, here is the bios setup with the geometry:

DSC00274_DxO.jpg
Filename
DSC00274_DxO.jpg
File size
123.83 KiB
Views
1752 views
File license
Fair use/fair dealing exception

But with chkdsk the dos shows only 52 MB, why is this ?

DSC00276_DxO.jpg
Filename
DSC00276_DxO.jpg
File size
121.17 KiB
Views
1752 views
File license
Fair use/fair dealing exception

Good thing is that i now have Dos 6.22 with Windows 3.11 running incl. the old network card i could get.
So i now have a new internet browse machine, although its not fun browsing with opera 3.62 on the toshiba 😉

DSC00279_DxO.jpg
Filename
DSC00279_DxO.jpg
File size
106.66 KiB
Views
1752 views
File license
Fair use/fair dealing exception

Reply 65 of 534, by IanB

User metadata
Rank Member
Rank
Member
kultakala wrote:

I did start from a dos floppy but it was version 4.01... i would say there was no memory manager.
But i did the bios dump again, with a dos 6.22 floppy with nothing on it but the command.com, bios.exe and debug.exe.

Unfortunately it's the same as before, it worked to dump the Award BIOS, perhaps the Phoenix BIOS stops the dump from working.
I'm fairly certain you have V3.00 Phoenix BIOS on your newer machine and V1.20 Award on your older machine and we already have both of those but just to confirm that, please download test3.exe (If you don't already have it)

Filename
TEST3.zip
File size
22.12 KiB
Downloads
78 downloads
File license
Fair use/fair dealing exception

Run this on the machines and select option 8 which will list the BIOS version number at the top.

kultakala wrote:

But with chkdsk the dos shows only 52 MB, why is this ?

Perhaps a smaller partition was created, run FDISK and see if there's any extra space for another partition.

kultakala wrote:

Good thing is that i now have Dos 6.22 with Windows 3.11 running incl. the old network card i could get.
So i now have a new internet browse machine, although its not fun browsing with opera 3.62 on the toshiba 😉

You need to upgrade your CPU & RAM 🤣

Reply 66 of 534, by kultakala

User metadata
Rank Newbie
Rank
Newbie
IanB wrote:

Run this on the machines and select option 8 which will list the BIOS version number at the top.

I will do and check it... i am thinking about getting another floppy drive for the second machine, but maybe i just swap the hard disk so i can check the other bios.

IanB wrote:

Perhaps a smaller partition was created, run FDISK and see if there's any extra space for another partition.

Okay, i will check that. I forgot all that old basic dos stuff 🤣

IanB wrote:

You need to upgrade your CPU & RAM 🤣

I have 6 MB RAM, what is the maximum without building an adapter like you did ?
But its not possible to get old ram i guess.

Have to think about a cpu upgrade...
Is it possible to just swap the cpu or do i have to make mainboard modifications with some of the cpus ?

And regarding a new Bios. I guess i could use the HIMEM XTIDE Award 5.30 Bios, right ?
What would i need to burn the bios by myself ?
Are there new compatible eeproms or would i have to use the old one from the toshiba ?

Reply 67 of 534, by Vipersan

User metadata
Rank Oldbie
Rank
Oldbie

The chips needed for bios are any 1024 type ..
Expensive on Ebay ..but relatively cheap on AliExpress
https://www.aliexpress.com/item/Free-shipping … iceBeautifyAB=0

If you want to program these ..The TL866 does this well enough....and of course ..you will need a UV eraser if you want to re-use the chips.

https://www.youtube.com/watch?v=FLG03f_ua5g

I have seen the TL866 for as little as £50 ..but usually around £80

As to the hard drive size ..
I wonder if the partition size was reduced deliberately ..due to the classic ..leaky oil bearing scenario ..which apparently does tend to destroy around 50% of the HD platter ?

Reply 68 of 534, by kultakala

User metadata
Rank Newbie
Rank
Newbie
Vipersan wrote:

The chips needed for bios are any 1024 type ..
Expensive on Ebay ..but relatively cheap on AliExpress

Thanks, i checked and i can get 27c1024 eproms for about 8 $ here... have to check if someone can program them for me.

Edit: My local dealer can programm the eproms for me, for 5 Euros 😀
Dont know yet if they have the right eproms available...

I checked for the Bios, its V3.10 in my case...

So i would go for the Award 5.30 BIOS with the LOWMEM XTIDE, right ?

Reply 69 of 534, by IanB

User metadata
Rank Member
Rank
Member
kultakala wrote:

I checked for the Bios, its V3.10 in my case...

That's one we don't have so it's worth trying again to read it, this time using debug.
Could you try the following from a freshly powered up machine booted straight to a DOS floppy.
DEBUG
N BIOS310.BIN
M F000:0 FFFF 8000:0
R BX
1
R CX
0
W 8000:0

You should end up with a file "BIOS310.BIN"
To check if the dump is potentially good, try loading it into notepad and you should get random letters and numbers. If it's almost all the same character at the beginning then the dump is bad (try loading one of the earlier dumps to see what I mean). There will be some blocks of the same chars as that's the free space where I put XTIDE etc.

kultakala wrote:

So i would go for the Award 5.30 BIOS with the LOWMEM XTIDE, right ?

Yes, LOMEM or HIMEM should be OK and that's the latest version to use. We haven't found any issues with it so far and it seems to boot faster than Phoenix 3.00

kultakala wrote:

I have 6 MB RAM, what is the maximum without building an adapter like you did ?
But its not possible to get old ram i guess.

In addition to the onboard 2MB of RAM, you can put 3 "sets" of RAM in which can either be 3x 2MB giving 8MB total or 2x 2MB + 1x 8MB giving 14MB total.
You have two sets of 2MB so you can either fit another 2MB or 8MB set (or fit an 8MB 72 pin SIMM using my mod)
I looked some years ago but couldn't find anyone with any stock left
You might be able to use a 16 bit ISA memory expansion board for memory below 16MB but that might not work and would be very slow even if it did.

kultakala wrote:

Is it possible to just swap the cpu or do i have to make mainboard modifications with some of the cpus ?

You can just plug in the CPU and it will work faster than the 386, the hardware mods improve the speed even more.
In the above info the benchmark for "no hardware mods" means the CPU was just plugged in.

Reply 71 of 534, by IanB

User metadata
Rank Member
Rank
Member
kultakala wrote:

Okay, i think now it worked to get the Bios dump...

Yes thanks, that worked this time although it's virtually identical to the V3.00, the only difference is that the text "FOR EVALUATION ONLY" has been removed and the version number changed.
As it was effectively the same, I ran my patch program on it and reuploaded the BIOS pack with patched versions of that one as well:

Re: Toshiba T5200 mods and upgrades

Reply 75 of 534, by kultakala

User metadata
Rank Newbie
Rank
Newbie

I ordered an upgrade processor on ebay...
And i was able to get the last 27c1024 Eprom available in the whole town 😉 So i can burn new Bios the next days, my local electronics store will do it for me.
One question about RAM. I have 6 MB and guess its impossible to get original RAM nowadays ?
Seems to be some non standard RAM with 40 pins ?

Would it really be worth to make a SIMM adapter ?
Guess i will "use" the T5200 only very occasional to show someone a historical laptop 😀

Reply 76 of 534, by IanB

User metadata
Rank Member
Rank
Member
kultakala wrote:
One question about RAM. I have 6 MB and guess its impossible to get original RAM nowadays ? Seems to be some non standard RAM wi […]
Show full quote

One question about RAM. I have 6 MB and guess its impossible to get original RAM nowadays ?
Seems to be some non standard RAM with 40 pins ?
Would it really be worth to make a SIMM adapter ?
Guess i will "use" the T5200 only very occasional to show someone a historical laptop 😀

Yes it uses proprietary 40 pin SIMMs so the chances of finding any would be slim.

I think 6MB is probably enough for demo purposes, you could even run Windows 95 with that.

Reply 78 of 534, by kultakala

User metadata
Rank Newbie
Rank
Newbie

Now i have the new Bios running, works perfect!
My thanks to IanB!

And i replaced the Conner disk with a DeLock 1 GB Flash disk.
Boot and start up speed of windows and applications has doubled 😀

Next thing is that i will try to get the second T5200 working again...

Edit: My second T5200 does nothing anymore... after replacing the floppy drive it starts, power led lits but nothing else... Hmmm...

Reply 79 of 534, by Vipersan

User metadata
Rank Oldbie
Rank
Oldbie

Hi again Ian ..
I guess I have found a workable solution for keeping the temperature of the 486 at a reasonable level ..
I have yet to start the SIMM/RAM mod ..but at some point I am going to have to bite the bullet and pull the mainboard out to do the 486 CPU mods ..
Been back through you thread ..and not seeing any real detail for this..unless I missed it.
Did I miss something ..or perhaps you haven't posted the details yet.
With close up photos if posssible .
rgds
and as usual ..my grateful thanks
VS
..oh and btw ..
Temp meter never got above 50 degrees C in over 12 hours..
though there is margin for error here..