Search found 774 matches

by iss
Tue Mar 19, 2019 8:56 am
Forum: Technical questions
Topic: Atmos ROM 1.1, 1st version (called 1.1a, checksum A65D6CED)
Replies: 3
Views: 97

Re: Atmos ROM 1.1, 1st version (called 1.1a, checksum A65D6CED)

Thanks for the effort, Symoon! This confirms my expectations - the code related to CLOAD is exactly the same as in the Pravetz-8D ROM! I want to "investigate" when the Pravetz was copied from Oric :). You said this particular Oric is an Atmos, do you have more info about it like production date, ser...
by iss
Tue Mar 19, 2019 8:39 am
Forum: Technical questions
Topic: Oric Atmos Won't Initialise
Replies: 14
Views: 330

Re: Oric Atmos Won't Initialise

+1 that it's bad RAM chip (160Ohms between GND and +5V is low). Else everything helpful is already said. From the picture we can conclude that 12MHz generator (XT1+IC21) and ULA are working. When the logic probe arrives you can check the presence of F2 signal and event what happens on the address/da...
by iss
Mon Mar 11, 2019 7:22 pm
Forum: Technical questions
Topic: Cumulus with Wifi/SD Card?
Replies: 1
Views: 111

Re: Cumulus with Wifi/SD Card?

This is very interesting device indeed! I bought a cheap one and after month will give feedback how it works with cumulus :). If it works this will be not only timesaver for developers (and for lazy users ;)) but also will preserve the SD card connector which in cumulus is very fragile part ! ezshar...
by iss
Mon Mar 11, 2019 10:46 am
Forum: Technical questions
Topic: Oric Microdisc: Master/Slave selection
Replies: 11
Views: 281

Re: Oric Microdisc: Master/Slave selection

Attached is some info about connecting more drives. Hope it's helpful.
fdd.zip
(1002.16 KiB) Downloaded 7 times
by iss
Mon Mar 11, 2019 8:33 am
Forum: Technical questions
Topic: Replace XT1 and XT2 crystals
Replies: 8
Views: 322

Re: Replace XT1 and XT2 crystals

Any 12 MHz will work. For repair I prefer to use crystals with small footprint:
12mhz.jpg
12mhz.jpg (10.06 KiB) Viewed 289 times
BTW, many Oric's have a transistor soldered next to modulator (i.e. not only a capacitor) - this is not a repair but 'standard' feature :).
by iss
Sat Mar 09, 2019 5:03 pm
Forum: Tape and floppy disk converters
Topic: Novalight - very fast tape loading
Replies: 67
Views: 2755

Re: Novalight - very fast tape loading

For the poll : If it's not too difficult - detect and discard it during WAV generation. Here is the quick disassembly of ALC: LE7B6 := $E7B6 LE867 := $E867 LEE22 := $EE22 php sei lda $FFF9 cmp #$01 bne L02B2 lda $E4B6 cmp #$A2 bne L02A6 ldy #$09 L0293: lda L02B5,y sta $0221,y dey bpl L0293 lda #$21 ...
by iss
Thu Mar 07, 2019 5:43 pm
Forum: 6502 assembly coding
Topic: How to create random number with machine code?
Replies: 12
Views: 860

Re: How to create random number with machine code?

Well spotted, goyo ! This algo actually generates chains with period of 256 and "will cycle through the values $00-$ff exactly once, in a scrambled order". I.e it's like doing "shuffle" but with 256 cards :). I recall that I've used this code because it was small and I needed only numbers in range 0...
by iss
Wed Mar 06, 2019 10:22 am
Forum: 6502 assembly coding
Topic: Help with a "Your computer" program
Replies: 11
Views: 717

Re: Help with a "Your computer" program

This helped lot, @Steve M! :)
Attached are working BAS and TAP files.
Now we waiting some animations from @peacer! ;)
by iss
Sat Mar 02, 2019 1:36 pm
Forum: Technical questions
Topic: Oric Speech Synthesizer + Cumulus/Microdisk
Replies: 23
Views: 1029

Re: Oric Speech Synthesizer + Cumulus/Microdisk

It's "Molex MiniFitKK 4pin Header Male 2.54mm" or from China "a2542 connector". Assembled cable - HERE (link is just example). Unfortunately google image search returns only white or brown connectors. Keep in mind that female connectors are sold as housing and metal pins separately. I have 2 such ca...
by iss
Sat Mar 02, 2019 9:26 am
Forum: Technical questions
Topic: Oric Speech Synthesizer + Cumulus/Microdisk
Replies: 23
Views: 1029

Re: Oric Speech Synthesizer + Cumulus/Microdisk

Everything looks very beautiful, congrats! And the best is that works with Cumulus.
What is the text being spoken? It's bit hard to understand for me "This is .... cyber...." :roll:
by iss
Fri Mar 01, 2019 7:40 pm
Forum: Technical questions
Topic: Dead oric 1
Replies: 48
Views: 1721

Re: Dead oric 1

Can you take a picture from this side?
Screenshot_20190301_203607.png
by iss
Fri Mar 01, 2019 7:06 pm
Forum: Technical questions
Topic: Dead oric 1
Replies: 48
Views: 1721

Re: Dead oric 1

Traindriver69 wrote:
Fri Mar 01, 2019 7:03 pm
I have tried it through the rf cable to a tv and nothing and keyboard no sound.
So, nothing means just black TV screen or there are bars or something? Can you try with SCART?
by iss
Fri Mar 01, 2019 6:42 pm
Forum: Technical questions
Topic: Dead oric 1
Replies: 48
Views: 1721

Re: Dead oric 1

From your first post:
... so plugged my power supply into it and nothing
What means 'nothing' here? If you attach a monitor, is anything displayed on it?
by iss
Thu Feb 28, 2019 4:51 pm
Forum: Technical questions
Topic: Dead oric 1
Replies: 48
Views: 1721

Re: Dead oric 1

OK, you can try another measuring - it's not scientific, but in practice is used sometimes: Remove the power adapter, set the multi-meter to measure resistance (2k) and measure again at IC10 (or IC11) - i.e. black probe to black arrow and red probe to red arrow - warning again do this with UNPOWERED...
by iss
Thu Feb 28, 2019 4:24 pm
Forum: Technical questions
Topic: Dead oric 1
Replies: 48
Views: 1721

Re: Dead oric 1

Stop! 2m is too small and can damage the multi-meter!
You can use 20m/10A - but put the probe in the other hole as on picture (where is a label 10A).
amper1.jpg
amper1.jpg (37.09 KiB) Viewed 394 times