@Dbug yeah was me:
https://www.exxosforum.co.uk/forum/viewt ... 97&p=52817
Mega STe stability issues.
Re: Mega STe stability issues.
I finally received my parts for the machine (resistors, gals, etc...) and I looked on this thread about how to install the pullup on the FDC, but I realize that the location where people connects to get the +5v on the 1st pin on the SIL resistor does not match the Mega STe layout.
So before I do anything stupid, can someone confirm on the following picture that the 8 pins are to be soldered on the red highlighted area on the WDC... and what would be a proper location where to fetch the +5v for the last pin?
Thanks
So before I do anything stupid, can someone confirm on the following picture that the 8 pins are to be soldered on the red highlighted area on the WDC... and what would be a proper location where to fetch the +5v for the last pin?
Thanks
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Re: Mega STe stability issues.
Should be fine off the IC but there are plenty of other places to pick 5v off, just check with a multimeter.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Re: Mega STe stability issues.
Does that look ok?
I reverted the SIL (the marking is toward the rear of the computer) so the pin with a dot is closer to the Vcc pin.
I reverted the SIL (the marking is toward the rear of the computer) so the pin with a dot is closer to the Vcc pin.
Re: Mega STe stability issues.
That looks right. I'm interested to see the result.
Re: Mega STe stability issues.
I need to do proper testing, but at least some large programs (big demos which required 4 megs of ram to load) seem to be more reliable, there were a couple of them which would crash at some point, and I ran them a dozen time in a row without any problem.
Next step is to add the VME card and see if the program which generated checksum errors is now running fine or if it still has these data errors.
Re: Mega STe stability issues.
That's promising. I noticed mine is a bit more stable with a gotek attached instead of a modern floppy. Leads me to think bus pull up will help.
Re: Mega STe stability issues.
One thing to bare in kind is there are 2 fixes doing different things. The DMA pullups which help with floppy and hard drive issues and the 1772 pullups which are needed for modern floppy drives like the MPF920. The gotek has the "1772 pull ups" already built in.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.