I've searched for "frequency generators" on 2 of those sites and was led to VCO's. I'll try signal generators on all those manufacturers tonight.

Garth, where did you see this type of IC? I searched and searched and I just find PLL's for cell phones and other GHz devices...

With the 'S124 VCO I was able to swing the frequency out from 5MHz to 14.7MHz, with a corresponding Vin from 0 to 4.7V.

Did some measurements on a breadboard with me new scope Seems the 'S124 is very stable even when using 'el cheapo Radio Shack picoFarad cap's. With a 1pF cap on the 'S124, an 'F269 was counting close to the 100MHz range. It sure stayed alot cooler than the 'S124, even though it was above it's typFreq of 85MHz. The signal from the 'S124 looked more like a sine wave than a square wave on the clock input of the 'F269. The higher 'n' bit divider out pins of the 'F269 had nice square wave outputs, which shows the counter was still in action.

EDIT:Here is a plot of an 'S124 with 2 10pF cap's in parallel. This 1/2 of the 'S124 will be used for 6502 Phase 2 timng probably with an 8 position DIP switch and an R/2R ladder. The other 1/2 will be used for the 16-bit counter timing, expected to be around 2-5MHz which will be controlled by a 6502 through an ADC0808 DAC.

We used to call them "phase accumulating oscillators"
now they're (apparently) called numerically controlled oscillators

So try Googling "numerically controlled oscillator" and/or
"direct digital synthesis"


http://en.wikipedia.org/wiki/Direct_Digital_Synthesis

Did you see this topic:
viewtopic.php?t=1168 ?

I apologize that I haven't dug up the phase-accumulator IC stuff yet. I know which file cabinet drawer it's in, but it'll take a little time.

No need to look it up, and thanks for that link Garth, I should have thought to do a search myself. It's abit late here tonight and I need to print a few things out for tomorrow and I will read up on it. But just an update on what I've done since my last post:

I've finished wire wrapping the basics and decided to post an updated pic here, instead of updating the layout pic from a few posts ago. The layout pic from a few posts ago was anticipated with no wirewrapping, just off the top of my head so to speak... After doing most of the wire wrapping and further research, turns out I don't need the voltage level translators from 5v to 3.3v from my board to the new haven display board,and I had to add another 'F138 for further memory mapping. The FSA506 datasheet says the I/O interface can accept 5v signals. Still doing research on the FSA506 chip...

Very strange, right after I purchased an 8-bit version fom New Haven Display, they removed it from their site, as I was looking for the flex-connector adapter after I received the product in the mail, which they have removed as well. No worries though as I have modded a flex "cable" from an old printer. I can say that the info that accompanied the display was garbage, almost like info was intentionally left out. It was just a CD with 1 PDF which I had already downloaded from their website. Very lame... Amp Display has much better info on their products, unfortunately you can't order direct from the website. But they do use the same FSA 506 display controller and explain alot more on their website and downloadable PDF's. They even have the datasheet on the FSA506 itself, which is extremely useful. I cannot post any info on here as the content is protected.

Today I was reading through the FSA506 datasheet repeatedly, and understand enough of how the interface works to start experimenting soon. Tomorrow, I'm going to start reading datasheets on new haven's product and amp displays product to contrast and compare the two, and to figure out all the ambiguities...

I replaced the DAC and opamp and R2R ladder idea.I just settled for two pots to manually control Phase 2 and Injector frequencies, and a transistor driver for a counter overflow LED.

Some of my earlier schematics I posted are wrong. Very simple and stupid mistakes, I will update schematics from the earlier pages soon. But I got the basics working and switched an 8 bit port '574 on and off, and it worked. Max frequency of the 65C02 was ~7MHz with a 70ns EEPROM. Just as Garth said, 7MHz would be the upper limit... I was intending the video display to be the last part of this project, but, it's going to have to be my focus here in the beginning as the datasheets are not very designer friendly. Here's some pics.

Here's a PITA, wiring the flex cable from an old printer PCB with 30AWG wire wrap (read earlier post as to why I had to do this):


Here's the basic IC's that are working. The 574 is switching on and off as per my simple program. I removed the rest of unnecessary IC's as they just add noise ATM.


Here's a pic of everything hooked up with no power. At the bottom are power LED, Reset button, and Terminal Count LED with driver transistor.


And, here is power on and tried a program to initialize the display. This is just a confirmation of wiring and power, so far so good, but I am not sure the display is initialized. The static on the display is not changing FYI.

Got it working!

FYI, the display is actually upsidedown on the vectorboard. The newhaven.com site has updated app notes and datasheets since I've written about them last on this thread, which has given me some ideas which eventually led me to figure out how it works. Had to hold the /RD signal high, instead of hooking it to the E signal as suggested in the display datasheet. Not their fault since I am using a 6500 series CPU. According to 6800 series CPU's (i.e 6809) the E signal is the phase 2 signal divided by 4. I never had the patience to wire in a divider so I tried just a straight phase 2, clocked at a low 1MHz. Wouldn't work. I'll have to work out the logic later... But holding the /RD line high through a 10K pull-up resistor worked for write only operation.

... it looks like the 8 bit version of the TFT display is still unavailable from newhaven, but I will still post my progress. ampdisplay is still selling their 8bit version...

Interesting how it works. Everytime color data is sent, the horizontal (x) counter is incremented automatically. I'll write back here tomorrow after stepping up the 6502 back to ~7MHz, and see if it still communicates well with the display...

Here's: $00 data,


$0F data,


$90 data,


and $E0.

Communication no prob at 7.2MHz, that is, no change in behavior from 1MHz to 7MHz with 02out at 139ns max.

still testing...

Having problems sending color MSB,LSB pixel data...

Anyone have similar problems?

It reacts to the 1st 8 bits sent and treats the second set of 8 bits sent as the 2nd pixel info.

For 65K color it needs 2x8bit data...

I think my problem may be the 5Volt "F-series" logic interfacing with the 3.3V display logic (i.e. FSA506), which even though it can accept 5V-in logic levels, may be experiencing "noise" because of the different logic level switching, especially at higher speeds. I've had to put in software delays for data to be written correctly, even at the lower 65C02 (1MHz)and Display (10MHz pixel) clock speeds...Though I do still have a problem sending sequenced MSB and LSB 8bit data for the expected 65K colors, irregardless of each clock speed..

Since a MAX of 7MHz CPU has been attained with F logic. HCT and even HC should not be a problem, and hopefully signal switching will be "cleaner". They are on order..

I would like to run the whole system at 3.3V, but the EEPROM and SRAM I'm using can't run at those low volts.

If the HC and HCT series logic doesn't fix the noise problem, I'll be looking for 3.3V EEPROM and SRAMs, and run the whole system at 3.3V, which unfortunately will limit the 65C02 to a lower speed. Looking at the data sheet...

I am pursuing programming this display because I've seen that with a simple manipulating of 3 8-bit data "i.e 18bit memory start" registers, a pixel can be put anywhere in the display.

Although the logic seems to favor horizontal writing speed versus vertical writing speed (because of the address auto increment feature), which is not going to be favorable in drawing a waveform. Have to wait here for a few more weeks to see!. Any thoughts welcome!!

I had the day off today and continued working on the project. Accidentally noticed that when I touched the metal bezel of the display, the data "cleared" up, when I was doing a clearscreen init to all black. So I soldered a ground wire to it, and guess what. All data cleared up, 99 % of reset's are good, with no software delays (My reset circuit is not the best with just one cap and 1 resistor, no schmitt trigger or logic yet, and it resets the 65C02 and the display, although I do have a sofware delay before 1st communication with the display). So I was able to repeat after about 6 hours of programming and troubleshooting, to get it to clear screen all black pixels, and draw a red line from 0 to 320 with no random pixels on the display, with a 16 pixel offset so it would wrap around to check continuity. So I saved that program, and began on my next character drawing subroutine...

Here's my new setup since I was able to lose the scope today. My wife hated it ("it" being the scope...oh well), but today I was happy to oblige her. Now there's room for the project in the vise in its place.



A small chunk of software using Mikal Kowalski's awesome assembler/disassembler. Saves me MANY hours of prototyping by monitoring zero page, memory, and cpu registers, compared to the old days of measuring voltages on ports. Translation: old school = LAME.




Early attempt at drawing an 8x8 pixel capital "A". Data is appearing to be limited to an 8x8 bit square which is good software math, but the colors are changing everytime I reset... Will figure it out...

And another vote for an awesome tool that helps soemthign fierce for hardware debugging by monitoring. Now, if only a settable hardware environment and english instructions

_________________
"My biggest dream in life? Building black plywood Habitrails"

Do you know how to do tables with MK's 65c02 assembler? Gonna have to make a character set soon.

I think so, am using tables in the pinball program. The .DB directive.

_________________
"My biggest dream in life? Building black plywood Habitrails"

If you are using an 8x8 font, you are welcome to copy mine.

Just download the SBC-3 support file and take the "font.inc" file. You may need to change the .byte to .DB, but a replace all from notepad will fix that quickly.

I generated my font by grouping all 256 characters by row #, top row first. It would be very easy for me to regenerate it to suit your needs, just let me know.

Daryl