Search found 919 matches

by iss
Fri Dec 06, 2019 10:50 pm
Forum: Technical questions
Topic: Cumana disk interface problem
Replies: 9
Views: 1608

Re: Cumana disk interface problem

Does anyone have a working Cumana + GOTEK setup and be able to share their experiences and how you get it to work. Maybe with some pictures as well? I am thinking of maybe getting a real 3.5” Floppy Drive but want to try the GOTEK first. My Goteks work fine with Cumana, Original Microdisc, @Slicebi...
by iss
Thu Dec 05, 2019 11:05 pm
Forum: Emulators
Topic: Oricutron 1.0 (EDIT: Now 1.2)
Replies: 167
Views: 110535

Re: Oricutron 1.0 (EDIT: Now 1.2)

@christian : Thanks! This is really very useful. Your PR's are already merged and I'll update developer builds asap. @ALL : Guys, please take a look at the short discussion we had about "Handling size-change of loaded DSK image file" started here . If you want to comment on github I opened new issu...
by iss
Thu Dec 05, 2019 10:43 pm
Forum: Technical questions
Topic: Atmos/Microdisk - ghost in the machine!?!?!?
Replies: 19
Views: 306

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

Yeah, this seems to get more and more difficult as time goes by :( Well, no way of making a copy of Blake's 7 or any demo disk created with FloppyBuilder, as they don't have any DOS format. Maybe it is time to start thinking again on a low-level diskcopy tool. I am quite sure we discussed that some...
by iss
Thu Dec 05, 2019 10:01 pm
Forum: Technical questions
Topic: Atmos ROM
Replies: 19
Views: 17632

Re: Atmos ROM

romdis.png This is the /ROMDIS signal on an unmodified PCB. Obviously there are no other "hidden" connections and the wiring is exactly as per schematics. So the secret should be in the EPROM chip. modes.png Looking in the PDF on page 3 in the table with operating modes - the only plausible case fo...
by iss
Sat Nov 30, 2019 8:06 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 63
Views: 1314

Re: New Member and New Oric Atmos Owner

Sounds right to me, so does that mean the CPU, VIA, and AY are ok? This is also hooked up to my Bench PSU and I can see that the Atmos is drawing 700 milliamps. Yes, this is the correct sound and it means 99.99% CPU,VIA and AY are OK (diag EPROM too, obviously :)). So the only suspect is the RAM, u...
by iss
Sat Nov 30, 2019 1:59 pm
Forum: Technical questions
Topic: Atmos/Microdisk - ghost in the machine!?!?!?
Replies: 19
Views: 306

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

Try this fix:
Keyboard-fix.png
Keyboard-fix.png (704.9 KiB) Viewed 218 times
Resistor's value is not critical - from 1k up to 10k should work, experiment with different values in the range.
Maybe changing TR2 with better NPN transistor can help too.
by iss
Tue Nov 26, 2019 10:15 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 63
Views: 1314

Re: New Member and New Oric Atmos Owner

Here my diagnostic ROM running on Oric without RAM.
The "busy tone" is bit tiny because no LM386 amplifier - the signal is directly from AY's output pins (not very good idea! :mrgreen: ).

by iss
Sun Nov 24, 2019 2:24 pm
Forum: Technical questions
Topic: Connecting to a tape recorder in 2019
Replies: 13
Views: 373

Re: Connecting to a tape recorder in 2019

Since we are talking tapes, not directly related to the discussion but could interest you, I just wrote a new blog post about the Oric tape format and problems: http://blog.defence-force.org/index.php?page=articles&ref=ART63 Interesting read Dbug, has anyone ever replaced R8 with a 10K resistor and...
by iss
Sat Nov 23, 2019 1:43 pm
Forum: Mags and books
Topic: CEO-Mag Christmas gift: John Sinclair interview available
Replies: 12
Views: 338

Re: CEO-Mag Christmas gift: John Sinclair interview available

Big thanks for the early xmas gift, it's cool reading.
Symoon wrote:
Sat Nov 23, 2019 12:34 pm
It's a complicated matter...
No doubt about it! So guys, let's support CEO-Mag!
Screenshot_20191123_141858.png
Screenshot_20191123_141858.png (11.04 KiB) Viewed 276 times
I've just extend my subscription using PayPal - it's easy 2 mouse clicks :)
by iss
Fri Nov 22, 2019 12:33 am
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 63
Views: 1314

Re: New Member and New Oric Atmos Owner

After I reread the whole thread, IMHO and in the context of the shorting the input/output of the regulator - everything can be broken, so it's worth to change IC8 and IC20. IC21 can be verified easily with the oscilloscope - on all signal pins you should see pulses. Unfortunately after these IC's on...
by iss
Thu Nov 21, 2019 4:10 pm
Forum: Emulators
Topic: Oricutron 1.0 (EDIT: Now 1.2)
Replies: 167
Views: 110535

Re: Oricutron 1.0 (EDIT: Now 1.2)

omelette wrote:
Thu Nov 21, 2019 3:54 pm
... leaving you with no way of returning to the Oric
'F1' works in debug mode too showing the pop-up menu.
Else you can change the PC register to known working address and continue emulation with F2.
by iss
Thu Nov 21, 2019 8:59 am
Forum: Technical questions
Topic: Connecting to a tape recorder in 2019
Replies: 13
Views: 373

Re: Connecting to a tape recorder in 2019

Hi @robcook , your link to amazon is invisible but it should point to this Cassette Player/Recorder : 81umDhTW6TL._AC_SX522_.jpg IMHO the player will work just like back in the old days :). One possible option for good tape cable is: CLICK HERE What's interesting the player has the same 2.5mm connec...
by iss
Wed Nov 20, 2019 11:55 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 63
Views: 1314

Re: New Member and New Oric Atmos Owner

About the address bus, doesn't the ULA also read the ram to get image data, thus changing the address bus lines? Yes, ULA sets the address lines but ONLY for RAM and only during the low level of F2. @SpaceFlightOrange: It will sound like joke but ... do you have inserted the ROM chip(s)? :) If you ...
by iss
Tue Nov 19, 2019 4:41 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 63
Views: 1314

Re: New Member and New Oric Atmos Owner

2 easy things to try before changing LS257 - fill the via with solder and check that flying CAP's pin do not touch underlying IC pin: IMG_0119.jpg Additionally you can try to temporary remove the capacitor. It's purpose is to delay slightly the RAS signal which is not always needed (i.e. depend on R...
by iss
Mon Nov 18, 2019 10:17 pm
Forum: Emulators
Topic: Oricutron 1.0 (EDIT: Now 1.2)
Replies: 167
Views: 110535

Re: Oricutron 1.0 (EDIT: Now 1.2)

christian wrote:
Mon Nov 18, 2019 10:11 pm
If I remember correctly, my modification works but the delay before the IRQ interrupt may not be accurate.
It's better than nothing :). If you can find your patch it would be great to merge it.