Welcome to the forum!

I have a Toshiba T3200SX, as well as a L40SX, which has two memory modules inside, which are not detected completely (2x8MB), instead it uses 2MB of each, giving me a total of 6MB. But only as long as I do not complete the reference disk setup routine, otherwise they dont work. And I have BIOS beeps at startup, which isnt an ideal situation. The total a of 6MB seems to run, but it is not as I would like. I havnt found any memory modules compatible yet that would qualify for one of these adjustments, maybe you can be of assistance, or you have some spare modules that could be used for such a task.

With regards to the XT-IDE, I sadly cannot be of assistance as a fellow Vogoner (You know who you are!) provided me with a flashed BIOS chip, so the XTIDE sits onboard, so to speak. But the vast majority of ppl - from what I gathered - went the network controller Boot ROM method.

cheers,
KCS

Thanks jaZz 😀

I've always been eager to get my hand on one of these Toshibas for a long time so i am very glad that i actually got one at last. Its in quite nice condition besides the floppy issue (i got the headers + cable home today so this weekend will be filled with crimping cables and testing the new floppy). I will try to dig out the information regarding what eprom this nic will accept and try to find some "burn service" or similar. That will be my next little project.

The L40sx is a little special in the RAM department as you know (well, i guess all ps/2s and others are too from this era?). I actually converted two 4MB simms for this machine (both work perfectly) but they can't be used simultaneously due to some machine restriction (its documented on that mcamafia page as well. Having the 4+2 onboard MB, i managed to source two 16MB simms and made the modification to those as well. Unfortunately, its only possible to cram 8MB out of each but i finally made the 16+2 MB max on this machine.

If you are interested in one of these 4MB simms, i can surely provide you with it. Are you located in europe by any chance? (i'm in Sweden btw). Just let me know and i'm sure we can get something going.

br

I would be very much interested what 16MB modules turned out to be working for you in 8MB without boot errors or memory errors in general like upon Windows 3.11 install for example. Then I could make the modification myself maybe. The notches are already prepared it seems by the last owner.

cheers,
KCS

Hi

Sure. I bought a pair of HP D4891A simm sticks and modified the jumpers a tiny bit (i can open the 40sx and snap some photos of the exact setting this weekend)

Original state simm prior to mod attached.

I have no issues at all. I run win 3.11 on it with networking via the lpt port (xircom pocket ethernet). The 60MB Conner drive was dead too when i got the machine (i guess most of them are nowadays) so i installed a ide/cf adapter + industrial flash (512MB) inside with drive overlay software on top (on-track from here: https://www.philscomputerlab.com/ontrack-disk-manager.html)

I run an 2GB SD card via adapter via EZ-BIOS (Ez-Drive)... Thank you for the info. A photo of the mod would be nice, I hope I can order some similar sticks and do it myself finally.

Glad to help out.

Here are some closeups. In this case, leave the "R1" as is (bridged) and just bridge "R3" and "R4" and it should be good.

Thank you very much for the info. I shall see whether I can acquire some of these and try it out myself. This project is long overdue.

PS: Found two online. Will try it out once they arrive.

Hi,

Sorry for bumping in this old thread but I managed to max out the RAM of my IBM L40SX just as instructed and wanted to confirm that this is the way to go. I got the exact same HP SIMM's for astronomic price, soldered the bridges for the 8MB PD code and booted up the reference diskette to set the new configuration. It mut be noted that only 15.5MB is usable in this configuration.

the thread was titled a bit misleadingly about XT-IDE and I was doing a ton of research into maxing the RAM of the L40 and ended up here.

The HP SIMM's are (I think) 16MB 50ns single-ranked non-ECC with parity and normal 'height'. I bought other SIMM's that had the same specs but had 5 bridges rather than 4 and it didnt work for some reason (ECC?). If there are other SIMM's out there that work, it might be handy to share that here. Please note that modding any 8MB SIMM will not work.

Now all thats left for me is to experiment with overclocking and messing with the internal 50 pin connector for modem/serial addon cards. I wanted to serially attach something like a raspberry pi to the unused COM2 internally but the pinout and presence detection is unknown and I cant use it (reference diskette knows that no addon card is installed). If anyone has the L40SX serial addon card, please let me know what the pinout is.

Hi Hawwy,

great work! 😀

Yes, the machine seem to allocate the top-most memory area for other purposes for some reason, i noticed the same thing. While i don't have the schematics, i did purchase a second L40sx some time ago where there was supposedly a screen issue (and it had, but putting some light pressure on the right-hand side of the frame remedies it so i think it might be something that doesn't really have connection properly). Anyway, this second L40sx came with the serial card installed.

If you want to, i can always try to snap a number of closeups of it if that may help you in some way?

(updated the title of the first post now to help potential simm-modders)

Resurrecting this thread to ask a general question about suitable 16MB sticks for the L40SX. From all the info I could find, there's isn't a definitive idiots' guide to modding SIMMs for the L40SX and what info is there tends to assume a certain amount of knowledge of electronics.

My question is, can the L40SX work with non-parity RAM? And if so, what adjustments do I need to make to the RAM I have as shown below?

I have a couple of 16MB EDO sticks. No name but the have 8 Mosel Vitelic V53C511740502K50 chips on one side. There are four pairs of solder points on the right hand side of the stick and from what I can see, the left connects to pins 67, 68, 69 and 70 and the right hand points are harder to work out. It seems as if the right hand points for pins 67, 68 and 69 are connected to each other while the final pin seems to go nowhere. The via for that joint just ends. I have tried shorting the points as per whatever examples I have found online, which is usually shorting the pairs at 69 and 70 and leaving the other two open. The L40SX won't even finish posting with that in.