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Re: MegaSTE repair
Posted: 30 Jul 2020 13:09
by rubber_jonnie
atari030 wrote: 30 Jul 2020 12:35
I should learn not to stuff around with things. She's all recapped, so I decided to drop a socket in for the Ym2149 in case that was causing some of the problems. Back to white screen....... Yes, I broke the golden rule. Do one thing at a time and test as you go.
So I'm ordering the diag cart before I get ahead of myself.
Yep, one thing at a time is the best way, it's the way I have to do my job. Otherwise how will you know if you fixed it? Bet you can't wait to get that cart :)
Re: MegaSTE repair
Posted: 30 Jul 2020 14:14
by atari030
My day job is designing, building, testing and repairing servers. After 25 years at it you'd think I know better. In saying that, a million dollar server cluster isn't as exciting as a MegaSTE.
Lucky the motherboard pics are online so I could double check a broken trace. Its deliberate for a bodge wire.
Re: MegaSTE repair
Posted: 30 Jul 2020 17:26
by Tomswork
My mega ste is held together with patches wires and repairs. And 1kg of new solder And duck tape
Tom
Re: MegaSTE repair
Posted: 30 Jul 2020 22:29
by atari030
Awesome. There is an proud old Kiwi tradition of using bailing twine and fencing wire to fix everything. :lol:
Diag cart ordered, now time to wait....... patience is not my thing.
Re: MegaSTE repair
Posted: 30 Jul 2020 22:50
by rubber_jonnie
It's my Mega ST that's held together with parcel tape and string, came to me Blitter-less, missing the sound chip and barely booting. My MSTE is practically perfect 😁
Re: MegaSTE repair
Posted: 31 Jul 2020 01:01
by atari030
Most of my machines are mickey mouse, I got a Falcon for $50au that was a basket case, for spares. Fixed it, rock solid ever since. My CT2 Falcon is the painful one. Compatibility isn't great and it irks me. I have 2 or 3 or 4 FM's, 2 E's, 2 MegaSTE's, 2 Mega ST's, 2 Falcons, a 520STM and a TT030. 2 800XL's, 2 130XEs, a 600XL and an XEGS. Portfolio, Lynx, Jaguar and 4 2600s. Atari has been my heroine for three and a bit decades. :?
The Commodores are just a side thing, but interesting. :-)
Re: MegaSTE repair
Posted: 31 Jul 2020 01:06
by Tomswork
I want to add a Atari pc1 to my collection. I seam to by lots of stuff label dead or parts online to find out they are in good condition.
Tom
Re: MegaSTE repair
Posted: 02 Sep 2020 13:58
by atari030
So.... waiting for the diag cart to get out of Sydney.... I decide to do some work on my MegaST2. Simple enough, fix the battery and mess with the ROMs, see if I can get a six chip KAOS or 1.04 working.... Nearly, it bombs with six chips installed. I'll wait for the cart to arrive then check over that again, meanwhile back to two chip 1.02. I must confess to a soft spot for 1.02. I've always considered it the best OS for gaming on the Pre E's anyway.
I thought I'd check out a spare MegaSTE keyboard too, like my other one and the TT the mylar are pretty knackered. I'll fix that one day. Meanwhile the mouse is drifting everywhere so I strip the keyboard and get into it, buzz out the port, resolder etc, etc. Even wired in a new socket on the off chance. It refuses to work, try another mouse, same deal, and another... back over it, recheck, it should be working???
Grab another (fourth) mouse and its working fine. Ahhhhhhh. :cry:
Moral of the story don't assume any mice in your mice box have good cables. :roll:
Re: MegaSTE repair
Posted: 02 Sep 2020 14:17
by rubber_jonnie
atari030 wrote: 02 Sep 2020 13:58
So.... waiting for the diag cart to get out of Sydney.... I decide to do some work on my MegaST2. Simple enough, fix the battery and mess with the ROMs, see if I can get a six chip KAOS or 1.04 working.... Nearly, it bombs with six chips installed. I'll wait for the cart to arrive then check over that again, meanwhile back to two chip 1.02. I must confess to a soft spot for 1.02. I've always considered it the best OS for gaming on the Pre E's anyway.
I thought I'd check out a spare MegaSTE keyboard too, like my other one and the TT the mylar are pretty knackered. I'll fix that one day. Meanwhile the mouse is drifting everywhere so I strip the keyboard and get into it, buzz out the port, resolder etc, etc. Even wired in a new socket on the off chance. It refuses to work, try another mouse, same deal, and another... back over it, recheck, it should be working???
Grab another (fourth) mouse and its working fine. Ahhhhhhh. :cry:
Moral of the story don't assume any mice in your mice box have good cables. :roll:
I presume you changed the jumpers for 6 chip operation? Jumper positions for 2-6 chip are here:
https://www.exxosforum.co.uk/forum/viewt ... &hilit=rom
Re: MegaSTE repair
Posted: 03 Sep 2020 00:40
by atari030
Yeah mate, I installed pins and jumpers and socketed the 74LS11. It spat out bus errors randomly after that, I tried three sets of ROM's. Removing the IC was hard yakka, plenty of ground and solder on both layers.
I'm more disappointed in myself for not checking my mice first. :-) At least the KB now has a fresh flow of solder. :mrgreen: