my03 wrote on 2024-10-09, 19:25:

Eirikr wrote on 2024-09-24, 21:01:

Long time lurker; first time poster and friend of garagemadlad. TBH I honestly didn't think he was gonna make an account; I feel […]
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Long time lurker; first time poster and friend of garagemadlad. TBH I honestly didn't think he was gonna make an account; I feel like I'm more hyped about his machine than he is! hehe.

Any luck with the TI TI486SXL2-G66-GA in the T5200, or any challenges to be aware of? Any ways to get some more clock speed? It seems like the cache + 486 will help much more with emulation; but might leave some SNES emulators wanting.

There is also this thread for a PGA168 to PGA132 custom interposer
Custom interposer module for TI486SXL2-66 PGA168 to PGA132 - HELP!

Has anyone used this interposer with any further, even more LUDICROUS SPEED CPU upgrades in their T5200s?!

So I guess I shall be going over there to ask there about it working with PGA-168 CPUs like: 5x86 chips from AMD, Cyrix, Cyrix 6x86 (M1), IBM/Cyrix 6x86L, Pentium Overdrive

Following this with great interest. I went with the CX486DRx2 upgrade and it made some significant change to performance, but I would be all ears in learning if anyone went "hyper-speed" with a 2/66 unit with a custom PCB 😀

After a 2.5 month hiatus due to hospitalizations and such I’m finally venturing back into the world outside my immediate survival needs.

I do want to follow up with @garagemadlad to see what sort of upgrades (especially CPU) he has done and go from there.

Smeltbeard wrote on 2024-11-21, 17:38:

fool wrote on 2022-12-30, 10:35:

Someone interested in 2MB and 8MB 40pin SIMM memory kits? Nothing is ready yet. Just scouting before I make any PWB & chip orders because these are not cheap. Also have to repair my test bench first, no RAMs without it.

fool - Do you still have any 40 pin SIMM boards or kits?

Also wanted to mentioned I saw a new batch of 3inONEder's are available https://conventionalmemories.com/wiki_cm/3inO … shiba_portables

I should have two sets, but those are development phase boards and visually not very good. I designed new version, but yet build any. I would build some just for fun, but these memory chips are quite pricey. Let see, maybe I will get some inspiration 😀

Hey I have T3200SX and I replaced the BIOS with modded Award /639K with xtide. During boot XTIDE detects 40mb conner at 1f0 but then doesnt boot from it and tries to boot from floppy only. When I booted dos 6.22 from floppy fdisk says no fixed drive detected.
Any ideas?

Hey, did anyone try any T6400 BIOS modding?

IanB wrote on 2018-01-16, 04:15:

One of the machines had 14MB of RAM, the second had 6MB and the last had only the standard 2MB so I modified that one by removing the proprietary SIMM slots from the RAM expansion board and making a small sub board with standard 72 pin SIMM slots. I then wired that to the RAM expansion board giving 14MB on that machine (2x2MB +1x8MB SIMMs).

Any info on this 72-pin SIMM sub board mod? I don't think I'll be able to obtain 2MB of 40-pin SIMMs to perform the memory mod described elsewhere in the thread.
If it's possible to solder a 72-pin SIMM to the first two slots for 2MB in a similar manner to the second two slots for 8MB I would maybe do that rather than bother with an entire sub board.

IanB wrote on 2018-02-04, 17:19:

The T5200 has 2MB of memory soldered on board and an expansion SIMM board with 6 and a half SIMM slots but uses proprietary 40 p […]
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The T5200 has 2MB of memory soldered on board and an expansion SIMM board with 6 and a half SIMM slots but uses proprietary 40 pin SIMMs.
Here are details on a mod to add 8MB of RAM using a standard 72 pin 8MB Parity SIMM. (Requires at least 2MB of proprietary SIMMs already fitted)
Use this info at your own risk, don't blame me if you damage your T5200!

The attachment simmslots.jpg is no longer available

The above shows both empty and fully populated boards with the proprietary SIMMs
The SIMM slots are numbered from left to right IS17 (A & B), IS16 (A & B), IS15 (A & B) and IS14 (parity)
SIMMs must be fitted in pairs as they are only 16 bits wide and the processor is 32 bits wide. Each pair of SIMMs gives a 2MB expansion so the memory can be expanded by 2, 4 & 6MB (2 + 2 + 2) however the centre pair of SIMMs can take a larger SIMM pair of 8MB giving a total of 14MB memory (2 + 8 + 2 of SIMMs plus 2MB on board). The RAM chips on the 8MB SIMMs are larger than those on the 2MB SIMMs and there was insufficient room for the Parity chips so they are fitted separately on the 30pin SIMM (IS14). Note although this is a 30pin SIMM it is a proprietary pinout.

The memory size is detected in order left to right, so you must have a 2MB pair of SIMMs fitted before you can fit the 8MB pair + parity.
This means you must already have 2MB of standard SIMMs fitted in order to do the 8MB mod described below.
If you don't have any additional memory you can still mod your system but it will be more complicated and will be discussed in another post.

First you need to obtain a standard 72 pin 8MB Parity Fast Page Mode (FPM) SIMM and some 40 way ribbon cable (e.g. an old IDE cable)
Then use hot melt glue to stick this SIMM to the edge of the parity socket (IS14) making sure no electrical contact is made:

The attachment RAMmod1.jpg is no longer available

Note the above board already has the required 2MB of standard SIMMs fitted as mentioned above. (You could optionally fit another 2MB in IS15 as well to give the maximum 14MB after this mod.)

Before proceeding any further, make sure there is enough clearance to fit the board back in the T5200. (You will almost certainly need to dismantle the T5200 completely to fit it back in)

Rip the ribbon cable back to 36 ways and cut into two strips approx 15cm (6in) long. Then using a ruler and sharp knife, score a line about 2mm from the end of one of the ribbon cables and do the same on the other side (not the other end) then pull the 2mm strip of insulation off using a pair of blunt nosed pliers. This should leave 36 wires exposed on the end of the ribbon.
Solder the exposed wires to pins 1-36 of the SIMM and then repeat this for the other ribbon, soldering to pins 37-72.

The attachment RAMmod2b.jpg is no longer available

Then turn the board over and solder the ribbon wires to the centre connector (IS16) according to the following table:
(I suggest wiring all the data lines first as they are all straight with no wires crossing)

Wire 1 to Pin 8 (Ground)
Wire 2 to Pin 2B (Data 0)
Wire 3 to Pin 2A (Data 16)
Wire 4 to Pin 3B (Data 1)
Wire 5 to Pin 3A (Data 17)
Wire 6 to Pin 4B (Data 2)
Wire 7 to Pin 4A (Data 18)
Wire 8 to Pin 5B (Data 3)
Wire 9 to Pin 5A (Data 19)
Wire 10 to Pin 1 (+5 VDC)
Wire 11 Not connected
Wire 12 to Pin 6 (Address 0)
Wire 13 to Pin 7 (Address 1)
Wire 14 to Pin 13 (Address 2)
Wire 15 to Pin 14 (Address 3)
Wire 16 to Pin 24 (Address 4)
Wire 17 to Pin 25 (Address 5)
Wire 18 to Pin 31 (Address 6)
Wire 19 Not connected
Wire 20 to Pin 9B (Data 4)
Wire 21 to Pin 9A (Data 20)
Wire 22 to Pin 10B (Data 5)
Wire 23 to Pin 10A (Data 21)
Wire 24 to Pin 11B (Data 6)
Wire 25 to Pin 11A (Data 22)
Wire 26 to Pin 12B (Data 7)
Wire 27 to Pin 12A (Data 23)
Wire 28 to Pin 32 (Address 7)
Wire 29 Not connected
Wire 30 to Pin 1 (+5 VDC)
Wire 31 to Pin 33 (Address 8 )
Wire 32 to Pin 34 (Address 9)
Wire 33 to Pin 20B (Row Address Strobe 3)
Wire 34 to Pin 17B (Row Address Strobe 2)
Wire 35 to Pin 22A (Parity bit 3 - bits 16-23)
Wire 36 to Pin 22B (Parity bit 1 - bits 0-7)

Wire 37 to Pin 18B (Parity bit 2 - bits 8-15)
Wire 38 to Pin 18A (Parity bit 4 - bits 24-31)
Wire 39 to Pin 23 (Ground)
Wire 40 to Pin 16B (Column Address Strobe 0)
Wire 41 to Pin 16A (Column Address Strobe 2)
Wire 42 to Pin 21A (Column Address Strobe 3)
Wire 43 to Pin 21B (Column Address Strobe 1)
Wire 44 to Pin 17A (Row Address Strobe 0)
Wire 45 to Pin 20A (Row Address Strobe 1)
Wire 46 Not connected
Wire 47 to Pin 19 (Read/Write)
Wire 48 Not connected
Wire 49 to Pin 26B (Data 8 )
Wire 50 to Pin 26A (Data 24)
Wire 51 to Pin 27B (Data 9)
Wire 52 to Pin 27A (Data 25)
Wire 53 to Pin 28B (Data 10)
Wire 54 to Pin 28A (Data 26)
Wire 55 to Pin 29B (Data 11)
Wire 56 to Pin 29A (Data 27)
Wire 57 to Pin 36B (Data 12)
Wire 58 to Pin 36A (Data 28)
Wire 59 to Pin 40 (+5 VDC)
Wire 60 to Pin 37A (Data 29)
Wire 61 to Pin 37B (Data 13)
Wire 62 to Pin 38A (Data 30)
Wire 63 to Pin 38B (Data 14)
Wire 64 to Pin 39A (Data 31)
Wire 65 to Pin 39B (Data 15)
Wire 66 Not connected
Wire 67 Not connected
Wire 68 Not connected
Wire 69 Not connected
Wire 70 Not connected
Wire 71 Not connected
Wire 72 to Pin 35 (Ground)

Note if a pin has "A" on the end it has to be soldered to the "A" side of IS16 and "B" means soldered to the "B" side of IS16
If no "A" or "B" is mentioned then either side can be used as they have the same signals, however note that the "A" and "B" sides have independent drivers so they are not connected together electrically. (The "A" side is the one closest to PJ1 - see second photo below)

The attachment RAMmod3.jpg is no longer available

Note that wires 1 & 72 in this picture are connected to alternate ground points, not the pins detailed above.

Another view showing "A" and "B" rows :

The attachment RAMmod4B.jpg is no longer available

After finishing, double check your wiring and if you have a multimeter, do the following tests:
First make sure +5v and ground aren't shorted together, then check continuity between +5v on the pcb (e.g. the + side of the electrolytic capacitor) and the wires going to the 8MB SIMM listed above as +5v. Do the same for the ground lines.
Finally connect the board up, power up and hopefully your BIOS will detect the extra RAM.

I have a T5200 which unfortunately only has the minimum 2MB RAM - all SIMM slots are empty. If I follow the above guide, can I simply connect a 2MB 72-pin parity FPM SIMM to slots 1 and 2 (instead of 3 and 4, but using the same connections shifted down), to increase my RAM to 4MB?