Search found 172 matches

by mikeb
Thu Dec 26, 2019 6:31 pm
Forum: Demos
Topic: Real Time 3D example
Replies: 26
Views: 4335

Re: Real Time 3D example

jbperin wrote:
Wed Dec 25, 2019 11:10 pm
But I was ignoring that the TWO first columns was condamned. Thank you so much !!
I give you this commit number : 81eea6fbe4bcb190b69514f762495b7daba8d298
Glad that sorted it :)

Mike.
by mikeb
Mon Dec 23, 2019 6:35 pm
Forum: Demos
Topic: Real Time 3D example
Replies: 26
Views: 4335

Re: Real Time 3D example

when a shape reach column 0 of screen, it kind of erases the rest of the line. I would be thankful to anyone that can help me solve this issue. I don't know if this is rated "too obvious" or "why did no-one tell me?", but in TEXT mode (not LORES 0/1) the first two columns are usually protected, as ...
by mikeb
Mon Dec 16, 2019 6:05 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 72
Views: 8193

Re: New Member and New Oric Atmos Owner

I never noticed that! I've just verified the ROM and yup, its on there!! not sure whats happened, It auto verifies after a burn . I've compared the rest of the ROM and its just that byte that's different. Well, I'd suggest your EPROM burner/verifier is next on the list of things to fix ;) Seriously...
by mikeb
Sun Dec 15, 2019 6:05 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 72
Views: 8193

Re: New Member and New Oric Atmos Owner

... but on second try it started up ok. You may indeed have a reset issue, check/replace the capacitor C21 (1uF/10V) -- or next time it "hangs", manually short CPU/6502 Pin 40 to Ground (CPU Pin 1 or 21) with a short wire -- just dab on and let go, if it then resets, the reset is definitely not hol...
by mikeb
Sun Dec 08, 2019 6:52 pm
Forum: Technical questions
Topic: Atmos/Microdisk - ghost in the machine!?!?!?
Replies: 28
Views: 4025

Re: Atmos/Microdisk - ghost in the machine!?!?!?

Steve M wrote:
Sat Dec 07, 2019 7:03 pm
power s mod004.jpg
This one didn't work (forum bug) -- I hope nothing important is on page 4 ;)
by mikeb
Sun Dec 08, 2019 6:50 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 72
Views: 8193

Re: New Member and New Oric Atmos Owner

Excellent news -- another one rescued :)
by mikeb
Fri Dec 06, 2019 5:37 pm
Forum: Technical questions
Topic: Atmos ROM
Replies: 24
Views: 20409

Re: Atmos ROM

the only plausible case for me is that the chip somehow enters "programming mode" and D0..D7 are inputs which allows the external (microdisc) EPROM to be read fine and because we don't have high voltage (12.5/13V) for programming the data is not changed, additionally the /ROMDIS pulse is much short...
by mikeb
Mon Dec 02, 2019 5:34 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 72
Views: 8193

Re: New Member and New Oric Atmos Owner

Hopefully some replacements will turn up this week. If it's still no go, then I think we're back to first principles -- get out the continuity tester, checking all 8 "row/col" addresses from the ULA are correctly connected to the correct pins on the multiplexer, that the other 8 address lines from ...
by mikeb
Sun Dec 01, 2019 9:20 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 72
Views: 8193

Re: New Member and New Oric Atmos Owner

Dbug wrote:
Sun Dec 01, 2019 8:38 am
That's when this happens you are glad you spent the time installing sockets instead of soldering directly the new chips :D
100% agree. That goes double when you venture into removing the PSG, VIA and CPU!
by mikeb
Sun Dec 01, 2019 9:18 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 72
Views: 8193

Re: New Member and New Oric Atmos Owner

A0 & A1 are like this (Pulsing): (Pulsing) A2 is like this: (Low) and A3 is like this: (Hi) A4-A7 are low and A8=A15 are all high. So it looks like it completed the first test and failed on the full test. A0/A1 are pulsing because somewhere the CPU is still running round 3 consecutive addresses, an...
by mikeb
Sat Nov 30, 2019 7:08 pm
Forum: Technical questions
Topic: Atmos/Microdisk - ghost in the machine!?!?!?
Replies: 28
Views: 4025

Re: Atmos/Microdisk - ghost in the machine!?!?!?

Are the letters being "typed" (with a keyclick, and you can delete them?) or are they just appearing on the screen (not really there, memory corruption, silent arrival) ? Only if it's memory corruption, rather than phantom typing, does this apply :- On the Cumana interface board, there is a preset t...
by mikeb
Sat Nov 30, 2019 7:02 pm
Forum: Technical questions
Topic: Atmos ROM
Replies: 24
Views: 20409

Re: Atmos ROM

the newly programmed 27c128 eproms (I tried several) will not allow the computer to boot when the Microdisk controller is attached, though it boots fine with the old 27c128 inserted?!? Assuming your EPROMS aren't broken/fake/mislabelled etc :- EPROMs for system ROMS and external devices (the disc i...
by mikeb
Sat Nov 30, 2019 6:52 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 72
Views: 8193

Re: New Member and New Oric Atmos Owner

I got nothing when running Mikes ROM, Can't answer for ISS's ROM, but when you say "got nothing", you must have a VERY early failure in the tests that are so bad I couldn't get a message up on screen. See the documentation -- error codes are put onto the address bus. "A RAM test will be performed a...
by mikeb
Tue Nov 26, 2019 6:04 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 72
Views: 8193

Re: New Member and New Oric Atmos Owner

So you think it’s still a ram issue? Does the pattern suggest the CPU might be functioning? TL;DR -- if you ripped out the CPU, VIA, PSG and ROM you'd still get a pattern :) The problem is that the pattern comes from the DRAM's imagination, it wasn't put there by anything, so it only shows that the...
by mikeb
Sun Nov 24, 2019 9:14 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 72
Views: 8193

Re: New Member and New Oric Atmos Owner

You're right, there is definitely a (good) pattern there. The cyan-red bars are about where I would expect the "white" bars in a black screen. If you count carefully, the pattern repeats 6 lines down and 16 characters across, which is 256 bytes later (6*40+16), which is normal. I just checked the AT...