forum.defence-force.org

NightBird wrote: ↑Mon Dec 09, 2019 10:35 pmFor ROM/EPROM + Microdisc compatibility and Phi2 improvement, please also read CEO-MAG no 288, april 2014, pp. 8-13.

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".

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 mor...

@ 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...

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...

@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 opene...

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...

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 plausib...

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...

Try this fix:
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.

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! ).

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...

Big thanks for the early xmas gift, it's cool reading.

Symoon wrote: ↑Sat Nov 23, 2019 12:34 pmIt's a complicated matter...

No doubt about it! So guys, let's support CEO-Mag!
I've just extend my subscription using PayPal - it's easy 2 mouse clicks

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...

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.

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...