AbeOwitz

My GBS8200 also fails on this STF, can't sync at all. Works on my STE though. (As best as can be expected for a stock GBS8200)

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First image is 5v & 12v power. Looks clean. 2nd image, Red is Horiz Sync. Yellow is Vertical Sync. Note the downward spike there... Noisy Vertical?

OK, so monochrome works fine. That eliminates a lot.

Found this schematic. I'm not using composite, just RGB & H & V sync, so that's not it either...

What's weird is the distortion occurs at exactly the same lines every frame. There's no rolling or randomness to it. So, whatever's wrong is occuring in sync with the video. I just watched a video where the STFs didn't have circuitry for composite sync? That on this model one can't just combine HSYNC and VSYNC? Edit: Found this, lessee if I have those components around... resistors yes, diodes probably, maybe transistor... https://www.atari-forum.com/viewtopic.php?p=310158&sid=5cabebd9f99a8943281e32ce45dc361b#p310158

It's good. Note that the distortion occurs at the same vertical line all the time. There's no rolling or randomness to it.

Thanks for the reply. :-) Right now, I'm running it though a Framemeister RGB to a Dell 2007 LCD. My other ST's work fine with the Framemeister. So, I'm pretty sure the problem is in this machine.

I picked up an STF in bad shape a while ago. Was able to fix some things, but I'm stumped with this one. Same pattern in both low & med res. Have not tried Hi-Res yet. (My hi-res monitor is also on the fritz. Prob. needs new caps.) I've reseated all socketed chips, swapped the power supply with a known working one. Also swapped the video chip, no changes. Bad EPROM/RAM? Bad capacitor? (No floppy hooked up here. Mouse and OS seem to work fine, just a video output issue...) I'm going to dig deeper, but figured I could ask here first to save me some time, in case this has been seen before. Any suggestions? Thanks

I have a couple of 520ST's and a STe w/4MB RAM. I upgraded one 520ST to 1MB, and replaced the external floppy drives with more modern mechanisms, that will do double sided 720k. I'm pretty sure I upgraded the BIOS with EPROMS to the latest. I also have a trashed 1040STf that I'm using for parts. Keeping another good STe for myself. They are packed away, but if you are interested, I can dig them out and take some pics, verify they work, etc. Edit: Found an old pic of the RAM upgrade I did years ago.

I would like to see something more like the RC-2014, http://rc2014.co.uk/ We could design backplane boards that fit in each Atari case, and plugin the modules we want. I suggest a modular architecture so we could use an FPGA, 65816 or 6502 as a CPU, or VBXE or an ANTIC/GTIA board for video out. In my 800XL, you'd have an L-shaped backplane board that fits all the IO ports, but can stack 2 cards deep on the side. OTOH, the 800 would have upright slots... I'm also looking into 65SPI, which would allow a bunch of cool hardware addons. http://sbc.rictor.org/io/65spi.html So, that could be a card as well... With SPI or I2C, we could easily add Ethernet or WiFI chips with built in TCP/IP stacks, LCD screens, sensors, etc. The bus would need to handle 8-16MHz, and based on the 6502.org forums, that may be difficult to achieve. Alternatively, 3.3 volts internally and use modern components, and use voltage level converters on the I/O...

I'm having trouble with 4.48 on SIDE2 (with Ult1MB SDX disabled). I can't type double characters. For example best I can get is: BASIC OF If I type a different character, then backspace, then F, I can finish the command. (Also happens in Altirra similarly configured.) Also BASIC OFF gives 170 file not found. How do I turn off basic? Is it possible to turn off basic in Ultimate1MB as well, or am I stuck with the options given? Thanks!

Yeah, I lose color artifacting with VBXE as well. FWIW, since your S-Video adapter puts out HDMI, I am happy with my HJ0801A-01E + PCB800099 kit from eBay... http://www.ebay.com/itm/HDMI-VGA-2AV-Rear-View-Monitors-8inch-1027-768-HJ080IA-01E-TFT-LCD-Display-/371515037326?hash=item568005968e:g:STUAAOSwSdZWeVav If only VBXE output HDMI... sigh...

Michael, It's not really a monitor, but an LCD with a pre-programmed driver board. You'd have to do a lot of research to find a driver board that can take S-Video and drive the LCD you want. I used http://www.panelook.com/index.phpto cross reference LCD's on eBay to find an IPS display model in the size I wanted. And I bought the LCD with the board so I knew they would work. (A lot of those boards are pre-programmed for a small set of LCD models, though a few people have been able to hack them. http://tech.mattmillman.com/lcd/rovatools/ftdi-ft232h/ ) There are S-Video to HDMI/VGA adapters out there. I tried one last year, but they shipped me a different model than pictured, and it didn't work. (Luckily it was through Amazon, so I got my money back.) I have a Dell 2007WFPb that takes S-Video input and works with A8. Add in a matching sound bar and you're good! (I used to have a Dell 2001FP with S-Video input. Sold it to another Atari guy.) But these are bulky and heavy, not too convenient to take to a retro computer meeting. :/ -Abe

I'd have to take a closer look and compare the two. The Framemeister did seem to have a better signal. It also outputs HDMI, which is superior to VGA. In my portable, I'm going from VBXE to GBS8220 to VGA to LVDS, so, it's not as sharp, but still 100X better than composite. OK, I will look into VFD display.