Thank you, At some point would like to update the Talkback design and roll in your adapter for a cleaner interface.
Yogi
Search found 35 matches
- Fri Sep 11, 2015 4:00 pm
- Forum: Hardware and Tech
- Topic: Adapter for Talkback card
- Replies: 5
- Views: 1106
- Wed Sep 09, 2015 3:20 pm
- Forum: Hardware and Tech
- Topic: Adapter for Talkback card
- Replies: 5
- Views: 1106
Re: Adapter for Talkback card
No worries If you get a chance, would like to see the schema also.srowe wrote:Sorry I've not replied, been busy building my FE3 card.
I'm aware of the frequency shift but I've not really experimented with it. I'll try it out shortly.
Yogi
- Fri Aug 21, 2015 6:07 am
- Forum: Hardware and Tech
- Topic: Adapter for Talkback card
- Replies: 5
- Views: 1106
Re: Adapter for Talkback card
Cool. Nice job sorting out the design shortcuts. I've looked at the Maplin reprint awhile ago and the original design does seem kind of 'wonky' to save a few chips. One thing that I found interesting was the V to F clock circuit. Very unique. Would like to hear your impressions of this feature, how ...
- Thu Jul 30, 2015 2:55 pm
- Forum: Hardware and Tech
- Topic: usefulness of partial inhibition (and not all) of the writing on the RAM expansion
- Replies: 12
- Views: 1350
Re: usefulness of partial inhibition (and not all) of the writing on the RAM expansion
what's happening on DATA BUS when CPU try to write on RAM with RAM's R/W line forced High ? CPU is putting data on it, the selected RAM is putting other data on it...... It's a problem! (isn't it?) It depends on how you are using /OE, /WE and /CS. If you are using these input separately then you wo...
- Mon Jun 29, 2015 5:04 pm
- Forum: Hardware and Tech
- Topic: SpeakJet ?
- Replies: 2
- Views: 717
Re: SpeakJet ?
Thanks for the reply, yes I had read that thread. My interest is mainly for more musical use of the Speakjet rather then TTS which the R Pi excels at.
Yogi
Yogi
- Mon Jun 22, 2015 8:37 pm
- Forum: Hardware and Tech
- Topic: SpeakJet ?
- Replies: 2
- Views: 717
SpeakJet ?
So I've been think about speech synth lately and an idea hit me. As some may be aware, there is a SpeakJet based product the AtariVox+ that is operated from the A2600's game port. As far as I can see, it's bit-banged from a game port pin at 9600 baud. The programmer's guide details the interface but...
- Mon Jun 22, 2015 8:17 pm
- Forum: General Topics
- Topic: VIC 20 MODERN LED SCREEN
- Replies: 29
- Views: 4450
Re: VIC 20 MODERN LED SCREEN
Hi, don't want to state the obvious, but didn't see anyone mention it. Your LED has multi-inputs, are you sure you have selected the correct input that you are plugged into? Even if you plug into the composite connector, most tvs have to be switched to that input in a menu. I have an old toshiba wit...
- Fri Apr 24, 2015 7:13 pm
- Forum: Hardware and Tech
- Topic: Verdict on 2-prong power supply reliability?
- Replies: 18
- Views: 1540
Re: Verdict on 2-prong power supply reliability?
@Yogi The excess heat does come from the regulator. Changing it to a switching will certainly reduce the heat but make sure you get a good quality regulator as cheap ones can cause a serious amount of ripple on the 5V line and potentially damage irreplaceable vintage custom chips. All very good adv...
- Fri Apr 24, 2015 4:48 pm
- Forum: Hardware and Tech
- Topic: Purpose of the vrw pin on the expansion port
- Replies: 20
- Views: 3568
Re: Purpose of the vrw pin on the expansion port
Thanks so much, your timing diagram is great! Just what I needed.
Yogi
Forgive meBlasphemy!yogi wrote:I think I got off track by trying to compare the VIC to an Atari, WRONG
Yogi
- Fri Apr 24, 2015 3:22 pm
- Forum: Hardware and Tech
- Topic: Purpose of the vrw pin on the expansion port
- Replies: 20
- Views: 3568
Re: Purpose of the vrw pin on the expansion port
The CPU is never halted. The beauty with he 6502 is that It only needs to work on one of the phases ( phi2 is high ) of the clock. Sure it starts to set up the address and r/w in the first phase but it doesn't need to. The time is enough when the clock is high and data is read or written on falling...
- Fri Apr 24, 2015 2:33 pm
- Forum: Hardware and Tech
- Topic: Verdict on 2-prong power supply reliability?
- Replies: 18
- Views: 1540
Re: Verdict on 2-prong power supply reliability?
Thanks very much! Still want to work a VIC-20 into the music! Hope Schema mass produces his MIDI interface someday. Yes, ditto on the MIDI card :) I've been digging into the project's github and going thru the original Maplin design (I found a 6850 in my junk box) I've started experimenting with a ...
- Fri Apr 24, 2015 1:52 pm
- Forum: Hardware and Tech
- Topic: Purpose of the vrw pin on the expansion port
- Replies: 20
- Views: 3568
Re: Purpose of the vrw pin on the expansion port
Oh, this is a bit confusing to me. I guess I had misunderstood the need for the 65245 xceivers, I thought they provided bus isolation when the 6502 was in RDY state to accommodate the VIC-1. RDY is pulled up and unused in the VIC-20 and irrelevant to this discussion. OK, now another question: how d...
- Fri Apr 24, 2015 12:39 pm
- Forum: Hardware and Tech
- Topic: Purpose of the vrw pin on the expansion port
- Replies: 20
- Views: 3568
Re: Purpose of the vrw pin on the expansion port
It is two different things. The data buss has to tristste on all 65xx internally regardless. VIC 20 also have buffers for isolating VIC chip and 6502. Both data AND address. The 6510 has an additional tristate capability for the address bus also, thus eliminating these external buffers. Thanks TLov...
- Fri Apr 24, 2015 10:26 am
- Forum: Hardware and Tech
- Topic: Verdict on 2-prong power supply reliability?
- Replies: 18
- Views: 1540
Re: Verdict on 2-prong power supply reliability?
One thing I've noticed with this VIC, there seems like alot excess heat from the heat sink. I've only been playing with it for about a month so don't know if this is the norm. But it got me thinking about replacing the original regulator with a switching mode one. Yogi I'd like to know if you are s...
- Thu Apr 23, 2015 7:28 pm
- Forum: Hardware and Tech
- Topic: Verdict on 2-prong power supply reliability?
- Replies: 18
- Views: 1540
Re: Verdict on 2-prong power supply reliability?
Oh --- yeah that's right. Now that you mention it, it's all coming back. So I guess that since the 2-prong VICs have most of the failure prone parts inside the computer, it doesn't really benefit to buy a high-quality third party power supply. Thats my take on it. OTOH if you have C64s and/or other...