Search found 922 matches

by iss
Tue Dec 10, 2019 1:06 am
Forum: Technical questions
Topic: Atmos ROM
Replies: 23
Views: 17837

Re: Atmos ROM

NightBird wrote:
Mon Dec 09, 2019 10:35 pm
For ROM/EPROM + Microdisc compatibility and Phi2 improvement, please also read CEO-MAG no 288, april 2014, pp. 8-13. :D
Thanks for refreshing the memories!
There are also other solutions but here the point is to confirm/bust the myth that with certain models EPROMs it can work "as is".
by iss
Sun Dec 08, 2019 9:53 pm
Forum: Technical questions
Topic: Atmos ROM
Replies: 23
Views: 17837

Re: Atmos ROM

Well, just the preparation for the test took lot of weekend time: for-romdis.jpg On the picture: Atmos and 8D "all-on-sockets"; Cumana; Silicebit's, 2x original and one bare PCB Microdisc; 2x 27128 (ST and Hitachi); 3x Gotek (1 HxC and 2 FlashFloppy). So, everything is ready, need some more free tim...
by iss
Sun Dec 08, 2019 2:14 pm
Forum: Technical questions
Topic: New Member and New Oric Atmos Owner
Replies: 68
Views: 1809

Re: New Member and New Oric Atmos Owner

@ SpaceFlightOrange : Great picture! Congrats for the result and happy time with your Oric. I bought my DRAM and spare ULA as well as a 8912 from Bulgaria. Does this mean someone has a load of Pravetz spares? Yes, there should be lot. As I already said all chips on eBay with sellers from Bulgaria ar...
by iss
Fri Dec 06, 2019 10:50 pm
Forum: Technical questions
Topic: Cumana disk interface problem
Replies: 13
Views: 1781

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: 111153

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: 28
Views: 628

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: 23
Views: 17837

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: 68
Views: 1809

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: 28
Views: 628

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

Try this fix:
Keyboard-fix.png
Keyboard-fix.png (704.9 KiB) Viewed 354 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: 68
Views: 1809

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: 530

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: 516

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 454 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: 68
Views: 1809

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: 111153

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: 530

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...