exxos's Atari, Amiga & retro forum

Would seem to conclude the TT is all working fine then at least.

yeah, now i need to find some compatible 4MB SIMMs to try and detect which (if not all) are not working properly...

i was hoping that by jumper configuration, i would be able to test 4MB at a time, but according to this:

http://the.protos.free.fr/TT030/tt-ram.htm#CA401058

it seems like all the slots have to be populated, with either 4x1MB or 4x4Mb...

I would try cleaning the contacts on the simms first (and indeed the sockets) with a IPA swab first and see if that solves the issues.

Also you could spray some IPA onto the contacts between the RAM card and TT. I would bet its a bad contact somewhere. I've not had that I can think of any simms ever failing, but had countless issues with bad contacts on them. Even if they look clean.. it doesn't take much to cause a malfunction.

yeah, i have some at work for cleaning the printheads of thermal printers.
i´ll give it a try tomorrow...

exxos wrote: 29 Aug 2017 21:06 Your problem drive sounds like its failing to spin up correctly ? Does it sound like its spinning up and spinning down all the time or spinning constant speed ?

I remember I had a IDE drive in my falcon for years, that one kept spinning up down all the time.. eventually it did spin up and I copied all my files off it.

I'm not so sure about SCSI drives, though doesn't sound like the drive is in the land of the living anymore. Normally you can hear the heads moving and resetting on power up also.... ?

i can hear the drive spin up before starting to make the "clanking" sound. also, failing HDDUTIL self test should mean the drive is dead almost for sure as it should probably execute diagnostic commands on the drive itself...

the Quantum drive has a 50 pin conector like the TT has natively. the IBM has a SCA conector with an adapter fitted. the 9.1GB replacement drive i ordered has the same conector as the IBM so i should be able to replicate the same conditions.

i´m also going to try and change the battery as some months ago i asked a friend who is now living in the US to get me 5 of the original spec batteries, instead of adapting 1.5V AA batteries, though if none is working i might have to do just that...

i really appreciate all the help that was forthcoming.

Sounds like the heads are failing to reset to track 0 :(

Other than cleaning the pins on the drive, maybe even resolder the pins, I don't think there is much else to do :(

If you class the drive as faulty, last thing to do is unscrew the top and see what is going on internally :)

ok, several updates...

so, after starting to use the quantum prodrive, i cleaned out a partition and started to to install and copy some programs from the PC to the TT.
i had a couple of 1.44MB floppies that were working and i was using them sequencially to transfer files to the TT.

at the same time, i was trying to find a working 720k floppy to be able to mount ST disk images and use them on the TT.
i had two boxes of old floppies and figured a couple would be working. this is where i now believe things went horribly wrong.

most of the floppies even made suicidal noises and clearly were not ok. some the TT would try and try to format, giving error messages and i would try again. in between, i would also be using the TT drive to pass the contents of what i was copying from the PC. this led to a probably 4 hour session of continuous drive operation, when i started getting errors when trying to read even the floppies that came from the PC.

at first, i thought it was dirt that had passed from the old floppies to the drive heads, so i took it apart, cleaned and tried again, with the same results.

i had a couple of Sony MPF-920 with BH chip and switched the resistor from SEL1 to SEL0. stupidly, i was only reasonably certain that one of them was working before trying them on the TT. so, i try both drives on the TT and they don´t work. Tried them on the PC (even using the conector on the cable before the "twist") and would not work on the PC either. another Samsung floppy drive is working on the PC in the meantime, so i know i can read and format the known working floppies.

out of desperation, i went and took the drive from the MegaSTe that was still on the box since it came from Exxos (sorry Chris, just not enough hours in the day!) and tried that one on the TT. also didn´t work. at this point i became suspicious.

surely it must be something else, i thought... maybe the PSU isn´t giving enough power to the floppy... so i conected the data cable to the TT and the power cable from an ATX PSU. same results.

so my thinking now is that the floppy controler chip "burned out" during the intense usage and formating trials. maybe i´m wrong and missing something else, i don´t know. i was almost reaching for the MSTE to switch the ICs but i was already at it for several hours, it was already past 2AM and decided to sleep on it and try again later today.
This also means that when i cleaned the TT-RAM expansion board with IPA swabs and checked the header pins, i had no way to run YAART (it was still on the boot floppy, argh...)

however, with the TT-RAM inplace, leaving the TT alone (while desperately searching information on the PC) would result in several bombs appearing for no reason on the desktop when i went back at him.

removing the TT-RAM board and waiting again did not result in a crash, though i waited only one time, so it´s not conclusive.

i tried to explain everything as best i could, sorry for the long post.

:o you know this sounds like the issues I saw on the st DMA circuit. For me, floppy drive would work on the PC but would fail on the st. Turns out no pull up resistor on the DMA/1772 data bus was to blame. I never had a TT and not looked at the diagram but it may not be a failed ic.. Considering you have issues with both floppy and hard drive, to me points to DMA issues.

I only had hard drive issues with the IBM 9.1GB drive.

since installing the Quantum 50MB drive, no hard drive issues at all.

Anzac wrote: 31 Aug 2017 15:54 I only had hard drive issues with the IBM 9.1GB drive.

since installing the Quantum 50MB drive, no hard drive issues at all.

Try the faulty drive in the mste ?